From a27d96231228cfcb9facc1cc49efe6cb1c16b535 Mon Sep 17 00:00:00 2001
From: Marvin Loebel <mloebel@vmray.com>
Date: Thu, 14 May 2020 19:23:44 +0200
Subject: [PATCH 1/6] Fix FFI divergence between python27-sys and python3-sys

---
 python3-sys/src/memoryobject.rs | 1 +
 python3-sys/src/object.rs       | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/python3-sys/src/memoryobject.rs b/python3-sys/src/memoryobject.rs
index 27d60d05..56c5af35 100644
--- a/python3-sys/src/memoryobject.rs
+++ b/python3-sys/src/memoryobject.rs
@@ -21,6 +21,7 @@ extern "C" {
         size: Py_ssize_t,
         flags: c_int,
     ) -> *mut PyObject;
+    pub fn PyMemoryView_FromBuffer(view: *mut Py_buffer) -> *mut PyObject;
     pub fn PyMemoryView_GetContiguous(
         base: *mut PyObject,
         buffertype: c_int,
diff --git a/python3-sys/src/object.rs b/python3-sys/src/object.rs
index 09df770b..8f4ca006 100644
--- a/python3-sys/src/object.rs
+++ b/python3-sys/src/object.rs
@@ -430,6 +430,10 @@ mod typeobject {
             unsafe { core::mem::zeroed() }
         }
     }
+    pub const PyBufferProcs_INIT: PyBufferProcs = PyBufferProcs {
+        bf_getbuffer: None,
+        bf_releasebuffer: None,
+    };
 
     #[repr(C)]
     #[derive(Copy)]

From 5b7c30562c75c40c10f5f69a906be3b7bb22bde5 Mon Sep 17 00:00:00 2001
From: Marvin Loebel <mloebel@vmray.com>
Date: Thu, 14 May 2020 19:24:51 +0200
Subject: [PATCH 2/6] Add support for the buffer protocol for read-only byte
 arrays

---
 python3-sys/src/object.rs      |   4 +-
 src/buffer.rs                  |  54 ++++++
 src/py_class/py_class.rs       |   8 +
 src/py_class/py_class_impl.py  |  20 +-
 src/py_class/py_class_impl2.rs | 331 ++++++++++++++++++---------------
 src/py_class/py_class_impl3.rs | 331 ++++++++++++++++++---------------
 src/py_class/slots.rs          | 166 +++++++++++++++++
 tests/test_class.rs            | 147 +++++++++++++++
 8 files changed, 757 insertions(+), 304 deletions(-)

diff --git a/python3-sys/src/object.rs b/python3-sys/src/object.rs
index 8f4ca006..3fd67bf6 100644
--- a/python3-sys/src/object.rs
+++ b/python3-sys/src/object.rs
@@ -109,13 +109,13 @@ mod bufferinfo {
         }
     }
 
-    pub type getbufferproc = extern "C" fn(
+    pub type getbufferproc = unsafe extern "C" fn(
         arg1: *mut crate::object::PyObject,
         arg2: *mut Py_buffer,
         arg3: c_int,
     ) -> c_int;
     pub type releasebufferproc =
-        extern "C" fn(arg1: *mut crate::object::PyObject, arg2: *mut Py_buffer) -> ();
+        unsafe extern "C" fn(arg1: *mut crate::object::PyObject, arg2: *mut Py_buffer) -> ();
 
     /// Maximum number of dimensions
     pub const PyBUF_MAX_NDIM: c_int = 64;
diff --git a/src/buffer.rs b/src/buffer.rs
index 4c0662c2..a411c67d 100644
--- a/src/buffer.rs
+++ b/src/buffer.rs
@@ -661,6 +661,60 @@ impl_element!(isize, SignedInteger);
 impl_element!(f32, Float);
 impl_element!(f64, Float);
 
+/// Trait for the backing storage of a PyBuffer provided from a Rust binding.
+///
+/// It is unsafe because its implementation needs to uphold certain invariants.
+/// See the method docs for more details.
+// TODO:
+// - Buffer request can not fail yet
+// - Buffer can not actually store data inside the object itself, only in a
+//   standalone owned object, which usually means a heap allocated reference counted
+//   container.
+pub unsafe trait BufferHandle: 'static + Send {
+    /// Returns the data of `Self` as a continous array of bytes.
+    ///
+    /// # Safety
+    ///
+    /// This needs to return an address that remains valid
+    /// and stable if `self` gets moved or transformed to or from a void pointer.
+    fn as_bytes(&self) -> &[u8];
+
+    /// Convert `self` into an owned void pointer.
+    ///
+    /// # Safety
+    ///
+    /// The returned pointer has to be a valid pointer that
+    /// can be converted back to `Self`.
+    fn to_owned_void_pointer(self) -> *mut libc::c_void;
+
+    /// Convert an owned void pointer back to `Self`. This takes owenrship of the pointer.
+    ///
+    /// # Safety
+    ///
+    /// The passed `ptr` has been created by this trait, and is only
+    /// used at most once to convert back to `Self`.
+    unsafe fn from_owned_void_pointer(ptr: *mut libc::c_void) -> Self;
+}
+
+#[doc(hidden)]
+pub struct BufferHandleRaw {
+    pub buf: *mut libc::c_void,
+    pub len: crate::Py_ssize_t,
+    pub owner: *mut libc::c_void,
+}
+
+impl BufferHandleRaw {
+    #[doc(hidden)]
+    #[inline]
+    pub unsafe fn new<T: BufferHandle>(handle: T) -> Self {
+        let slice = handle.as_bytes();
+        let buf = slice.as_ptr() as *mut libc::c_void;
+        let len = slice.len() as crate::Py_ssize_t;
+        let owner = handle.to_owned_void_pointer();
+        Self { buf, len, owner }
+    }
+}
+
 #[cfg(test)]
 mod test {
     use super::PyBuffer;
diff --git a/src/py_class/py_class.rs b/src/py_class/py_class.rs
index 80d6d64e..d3ce34bc 100644
--- a/src/py_class/py_class.rs
+++ b/src/py_class/py_class.rs
@@ -465,6 +465,10 @@ macro_rules! py_class {
                 /* as_number */   [ /* slot: expr, */ ]
                 /* as_sequence */ [ /* slot: expr, */ ]
                 /* as_mapping */  [ /* slot: expr, */ ]
+                /* as_buffer */ [
+                    bf_getbuffer: {},
+                    bf_releasebuffer: {},
+                ]
                 /* setitem_delitem */ [
                     sdi_setitem: {},
                     sdi_delitem: {},
@@ -495,6 +499,10 @@ macro_rules! py_class {
                 /* as_number */   [ /* slot: expr, */ ]
                 /* as_sequence */ [ /* slot: expr, */ ]
                 /* as_mapping */  [ /* slot: expr, */ ]
+                /* as_buffer */ [
+                    bf_getbuffer: {},
+                    bf_releasebuffer: {},
+                ]
                 /* setitem_delitem */ [
                     sdi_setitem: {},
                     sdi_delitem: {},
diff --git a/src/py_class/py_class_impl.py b/src/py_class/py_class_impl.py
index c70fc4d7..6aee72ce 100644
--- a/src/py_class/py_class_impl.py
+++ b/src/py_class/py_class_impl.py
@@ -247,7 +247,8 @@ def write(text):
     ('nb', 'as_number', None),
     ('sq', 'as_sequence', None),
     ('mp', 'as_mapping', None),
-    ('sdi', 'setdelitem', ['sdi_setitem', 'sdi_delitem'])
+    ('bf', 'as_buffer', ['bf_getbuffer', 'bf_releasebuffer']),
+    ('sdi', 'setdelitem', ['sdi_setitem', 'sdi_delitem']),
 )
 
 def generate_case(pattern, old_info=None, new_info=None, new_impl=None, new_slots=None, new_members=None, new_props=None):
@@ -723,6 +724,19 @@ def inplace_numeric_operator(special_name, slot):
     operator(slot=slot,
              args=[Argument('other')])(special_name)
 
+@special_method
+def buffer_protocol(special_name, enabled):
+    if enabled:
+        pattern = 'def %s (&$slf:ident) -> $res_type:ty $body:block' % special_name
+        new_slots = []
+        for slot in ['bf_getbuffer', 'bf_releasebuffer']:
+            new_slots.append((slot, '$crate::py_class_buffer_slot!(%s, $class::%s)' % (slot, special_name)))
+        generate_case(pattern, new_slots=new_slots, new_impl='''
+            impl $class {
+                fn %s(&$slf, $py: $crate::Python<'_>) -> $res_type $body
+            }
+        ''' % special_name)
+
 special_names = {
     '__init__': error('__init__ is not supported by py_class!; use __new__ instead.'),
     '__new__': special_class_method(
@@ -870,6 +884,9 @@ def inplace_numeric_operator(special_name, slot):
     '__aiter__': unimplemented(),
     '__aenter__': unimplemented(),
     '__aexit__': unimplemented(),
+
+    # Buffer protocol
+    '__buffer__': buffer_protocol(not PY2),
 }
 
 def main():
@@ -907,4 +924,3 @@ def main():
 
 if __name__ == '__main__':
     main()
-
diff --git a/src/py_class/py_class_impl2.rs b/src/py_class/py_class_impl2.rs
index b87e57dc..975676dc 100644
--- a/src/py_class/py_class_impl2.rs
+++ b/src/py_class/py_class_impl2.rs
@@ -341,7 +341,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -353,7 +353,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_clear: $crate::py_class_tp_clear!($class),
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -370,7 +370,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -383,7 +383,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_absolute: $crate::py_class_unary_slot!($class::__abs__, *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -400,7 +400,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -413,7 +413,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_add: $crate::py_class_binary_numeric_slot!($class::__add__),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -442,7 +442,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -455,7 +455,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_and: $crate::py_class_binary_numeric_slot!($class::__and__),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -476,7 +476,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -489,7 +489,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_nonzero: $crate::py_class_unary_slot!($class::__bool__, $crate::_detail::libc::c_int, $crate::py_class::slots::BoolConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -501,11 +501,42 @@ macro_rules! py_class_impl {
     { { def __bool__ $($tail:tt)* } $( $stuff:tt )* } => {
         $crate::py_error! { "Invalid signature for operator __bool__" }
     };
+    { { def __buffer__ (&$slf:ident) -> $res_type:ty $body:block $($tail:tt)* }
+        $class:ident $py:ident $info:tt
+        /* slots: */ {
+            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt
+            /* as_buffer */ [
+                bf_getbuffer: {},
+                bf_releasebuffer: {},
+            ]
+            $setdelitem:tt
+        }
+        { $( $imp:item )* }
+        $members:tt $props:tt
+    } => { $crate::py_class_impl! {
+        { $($tail)* }
+        $class $py $info
+        /* slots: */ {
+            $type_slots $as_number $as_sequence $as_mapping
+            /* as_buffer */ [
+                bf_getbuffer: { $crate::py_class_buffer_slot!(bf_getbuffer, $class::__buffer__) },
+                bf_releasebuffer: { $crate::py_class_buffer_slot!(bf_releasebuffer, $class::__buffer__) },
+            ]
+            $setdelitem
+        }
+        /* impl: */ {
+            $($imp)*
+            impl $class {
+                fn __buffer__(&$slf, $py: $crate::Python<'_>) -> $res_type $body
+            }
+        }
+        $members $props
+    }};
     { {  def __call__ (&$slf:ident) -> $res_type:ty { $( $body:tt )* } $($tail:tt)* }
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -517,7 +548,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_call: $crate::py_class_call_slot!{$class::__call__ []},
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -529,7 +560,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -541,7 +572,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_call: $crate::py_argparse_parse_plist_impl!{py_class_call_slot {$class::__call__} [] ($($p)+,)},
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -569,7 +600,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt $as_number:tt
             /* as_sequence */ [ $( $sq_slot_name:ident : $sq_slot_value:expr, )* ]
-            $as_mapping:tt $setdelitem:tt
+            $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -582,7 +613,7 @@ macro_rules! py_class_impl {
                 $( $sq_slot_name : $sq_slot_value, )*
                 sq_contains: $crate::py_class_contains_slot!($class::__contains__, [Option<&$item_name>]),
             ]
-            $as_mapping $setdelitem
+            $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -595,7 +626,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt $as_number:tt
             /* as_sequence */ [ $( $sq_slot_name:ident : $sq_slot_value:expr, )* ]
-            $as_mapping:tt $setdelitem:tt
+            $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -608,7 +639,7 @@ macro_rules! py_class_impl {
                 $( $sq_slot_name : $sq_slot_value, )*
                 sq_contains: $crate::py_class_contains_slot!($class::__contains__, [&$item_name]),
             ]
-            $as_mapping $setdelitem
+            $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -621,7 +652,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt $as_number:tt
             /* as_sequence */ [ $( $sq_slot_name:ident : $sq_slot_value:expr, )* ]
-            $as_mapping:tt $setdelitem:tt
+            $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -634,7 +665,7 @@ macro_rules! py_class_impl {
                 $( $sq_slot_name : $sq_slot_value, )*
                 sq_contains: $crate::py_class_contains_slot!($class::__contains__, [$item_name]),
             ]
-            $as_mapping $setdelitem
+            $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -661,7 +692,7 @@ macro_rules! py_class_impl {
     { { def __delitem__(&$slf:ident, $key:ident : Option<&$key_name:ty>) -> $res_type:ty { $($body:tt)* } $($tail:tt)* }
         $class:ident $py:ident $info:tt
         /* slots: */ {
-            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt
+            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt
             /* setdelitem */ [
                 sdi_setitem: $sdi_setitem_slot_value:tt,
                 sdi_delitem: {},
@@ -673,7 +704,7 @@ macro_rules! py_class_impl {
         { $($tail)* }
         $class $py $info
         /* slots: */ {
-            $type_slots $as_number $as_sequence $as_mapping
+            $type_slots $as_number $as_sequence $as_mapping $as_buffer
             /* setdelitem */ [
                 sdi_setitem: $sdi_setitem_slot_value,
                 sdi_delitem: { $crate::py_class_binary_slot!($class::__delitem__, [Option<&$key_name>], $crate::_detail::libc::c_int, $crate::py_class::slots::UnitCallbackConverter) },
@@ -688,7 +719,7 @@ macro_rules! py_class_impl {
     { { def __delitem__(&$slf:ident, $key:ident : &$key_name:ty) -> $res_type:ty { $($body:tt)* } $($tail:tt)* }
         $class:ident $py:ident $info:tt
         /* slots: */ {
-            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt
+            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt
             /* setdelitem */ [
                 sdi_setitem: $sdi_setitem_slot_value:tt,
                 sdi_delitem: {},
@@ -700,7 +731,7 @@ macro_rules! py_class_impl {
         { $($tail)* }
         $class $py $info
         /* slots: */ {
-            $type_slots $as_number $as_sequence $as_mapping
+            $type_slots $as_number $as_sequence $as_mapping $as_buffer
             /* setdelitem */ [
                 sdi_setitem: $sdi_setitem_slot_value,
                 sdi_delitem: { $crate::py_class_binary_slot!($class::__delitem__, [&$key_name], $crate::_detail::libc::c_int, $crate::py_class::slots::UnitCallbackConverter) },
@@ -715,7 +746,7 @@ macro_rules! py_class_impl {
     { { def __delitem__(&$slf:ident, $key:ident : $key_name:ty) -> $res_type:ty { $($body:tt)* } $($tail:tt)* }
         $class:ident $py:ident $info:tt
         /* slots: */ {
-            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt
+            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt
             /* setdelitem */ [
                 sdi_setitem: $sdi_setitem_slot_value:tt,
                 sdi_delitem: {},
@@ -727,7 +758,7 @@ macro_rules! py_class_impl {
         { $($tail)* }
         $class $py $info
         /* slots: */ {
-            $type_slots $as_number $as_sequence $as_mapping
+            $type_slots $as_number $as_sequence $as_mapping $as_buffer
             /* setdelitem */ [
                 sdi_setitem: $sdi_setitem_slot_value,
                 sdi_delitem: { $crate::py_class_binary_slot!($class::__delitem__, [$key_name], $crate::_detail::libc::c_int, $crate::py_class::slots::UnitCallbackConverter) },
@@ -789,7 +820,7 @@ macro_rules! py_class_impl {
             $type_slots:tt $as_number:tt
             /* as_sequence */ [ $( $sq_slot_name:ident : $sq_slot_value:expr, )* ]
             /* as_mapping */ [ $( $mp_slot_name:ident : $mp_slot_value:expr, )* ]
-            $setdelitem:tt
+            $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -806,7 +837,7 @@ macro_rules! py_class_impl {
                 $( $mp_slot_name : $mp_slot_value, )*
                 mp_subscript: $crate::py_class_binary_slot!($class::__getitem__, [Option<&$key_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $setdelitem
+            $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -820,7 +851,7 @@ macro_rules! py_class_impl {
             $type_slots:tt $as_number:tt
             /* as_sequence */ [ $( $sq_slot_name:ident : $sq_slot_value:expr, )* ]
             /* as_mapping */ [ $( $mp_slot_name:ident : $mp_slot_value:expr, )* ]
-            $setdelitem:tt
+            $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -837,7 +868,7 @@ macro_rules! py_class_impl {
                 $( $mp_slot_name : $mp_slot_value, )*
                 mp_subscript: $crate::py_class_binary_slot!($class::__getitem__, [&$key_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $setdelitem
+            $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -851,7 +882,7 @@ macro_rules! py_class_impl {
             $type_slots:tt $as_number:tt
             /* as_sequence */ [ $( $sq_slot_name:ident : $sq_slot_value:expr, )* ]
             /* as_mapping */ [ $( $mp_slot_name:ident : $mp_slot_value:expr, )* ]
-            $setdelitem:tt
+            $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -868,7 +899,7 @@ macro_rules! py_class_impl {
                 $( $mp_slot_name : $mp_slot_value, )*
                 mp_subscript: $crate::py_class_binary_slot!($class::__getitem__, [$key_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $setdelitem
+            $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -888,7 +919,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -900,7 +931,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_hash: $crate::py_class_unary_slot!($class::__hash__, $crate::Py_hash_t, $crate::py_class::slots::HashConverter),
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -917,7 +948,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -930,7 +961,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_add: $crate::py_class_binary_slot!($class::__iadd__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -943,7 +974,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -956,7 +987,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_add: $crate::py_class_binary_slot!($class::__iadd__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -969,7 +1000,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -982,7 +1013,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_add: $crate::py_class_binary_slot!($class::__iadd__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -999,7 +1030,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1012,7 +1043,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_and: $crate::py_class_binary_slot!($class::__iand__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1025,7 +1056,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1038,7 +1069,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_and: $crate::py_class_binary_slot!($class::__iand__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1051,7 +1082,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1064,7 +1095,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_and: $crate::py_class_binary_slot!($class::__iand__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1085,7 +1116,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1098,7 +1129,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_floor_divide: $crate::py_class_binary_slot!($class::__ifloordiv__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1111,7 +1142,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1124,7 +1155,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_floor_divide: $crate::py_class_binary_slot!($class::__ifloordiv__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1137,7 +1168,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1150,7 +1181,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_floor_divide: $crate::py_class_binary_slot!($class::__ifloordiv__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1167,7 +1198,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1180,7 +1211,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_lshift: $crate::py_class_binary_slot!($class::__ilshift__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1193,7 +1224,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1206,7 +1237,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_lshift: $crate::py_class_binary_slot!($class::__ilshift__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1219,7 +1250,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1232,7 +1263,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_lshift: $crate::py_class_binary_slot!($class::__ilshift__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1249,7 +1280,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1262,7 +1293,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_matrix_multiply: $crate::py_class_binary_slot!($class::__imatmul__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1275,7 +1306,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1288,7 +1319,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_matrix_multiply: $crate::py_class_binary_slot!($class::__imatmul__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1301,7 +1332,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1314,7 +1345,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_matrix_multiply: $crate::py_class_binary_slot!($class::__imatmul__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1331,7 +1362,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1344,7 +1375,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_remainder: $crate::py_class_binary_slot!($class::__imod__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1357,7 +1388,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1370,7 +1401,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_remainder: $crate::py_class_binary_slot!($class::__imod__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1383,7 +1414,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1396,7 +1427,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_remainder: $crate::py_class_binary_slot!($class::__imod__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1413,7 +1444,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1426,7 +1457,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_multiply: $crate::py_class_binary_slot!($class::__imul__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1439,7 +1470,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1452,7 +1483,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_multiply: $crate::py_class_binary_slot!($class::__imul__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1465,7 +1496,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1478,7 +1509,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_multiply: $crate::py_class_binary_slot!($class::__imul__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1511,7 +1542,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1524,7 +1555,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_invert: $crate::py_class_unary_slot!($class::__invert__, *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1541,7 +1572,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1554,7 +1585,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_or: $crate::py_class_binary_slot!($class::__ior__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1567,7 +1598,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1580,7 +1611,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_or: $crate::py_class_binary_slot!($class::__ior__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1593,7 +1624,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1606,7 +1637,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_or: $crate::py_class_binary_slot!($class::__ior__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1627,7 +1658,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1640,7 +1671,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_rshift: $crate::py_class_binary_slot!($class::__irshift__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1653,7 +1684,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1666,7 +1697,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_rshift: $crate::py_class_binary_slot!($class::__irshift__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1679,7 +1710,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1692,7 +1723,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_rshift: $crate::py_class_binary_slot!($class::__irshift__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1709,7 +1740,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1722,7 +1753,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_subtract: $crate::py_class_binary_slot!($class::__isub__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1735,7 +1766,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1748,7 +1779,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_subtract: $crate::py_class_binary_slot!($class::__isub__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1761,7 +1792,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1774,7 +1805,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_subtract: $crate::py_class_binary_slot!($class::__isub__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1790,7 +1821,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1802,7 +1833,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_iter: $crate::py_class_unary_slot!($class::__iter__, *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1819,7 +1850,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1832,7 +1863,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_true_divide: $crate::py_class_binary_slot!($class::__itruediv__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1845,7 +1876,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1858,7 +1889,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_true_divide: $crate::py_class_binary_slot!($class::__itruediv__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1871,7 +1902,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1884,7 +1915,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_true_divide: $crate::py_class_binary_slot!($class::__itruediv__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1901,7 +1932,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1914,7 +1945,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_xor: $crate::py_class_binary_slot!($class::__ixor__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1927,7 +1958,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1940,7 +1971,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_xor: $crate::py_class_binary_slot!($class::__ixor__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1953,7 +1984,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1966,7 +1997,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_xor: $crate::py_class_binary_slot!($class::__ixor__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1988,7 +2019,7 @@ macro_rules! py_class_impl {
             $type_slots:tt $as_number:tt
             /* as_sequence */ [ $( $sq_slot_name:ident : $sq_slot_value:expr, )* ]
             /* as_mapping */ [ $( $mp_slot_name:ident : $mp_slot_value:expr, )* ]
-            $setdelitem:tt
+            $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2005,7 +2036,7 @@ macro_rules! py_class_impl {
                 $( $mp_slot_name : $mp_slot_value, )*
                 mp_length: Some($crate::_detail::ffi::PySequence_Size),
             ]
-            $setdelitem
+            $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2026,7 +2057,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2039,7 +2070,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_lshift: $crate::py_class_binary_numeric_slot!($class::__lshift__),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2068,7 +2099,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2081,7 +2112,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_multiply: $crate::py_class_binary_numeric_slot!($class::__mul__),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2102,7 +2133,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2115,7 +2146,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_negative: $crate::py_class_unary_slot!($class::__neg__, *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2131,7 +2162,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2143,7 +2174,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_new: $crate::py_class_wrap_newfunc!{$class::__new__ []},
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2155,7 +2186,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2167,7 +2198,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_new: $crate::py_argparse_parse_plist_impl!{py_class_wrap_newfunc {$class::__new__} [] ($($p)+,)},
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2182,7 +2213,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2194,7 +2225,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_iternext: $crate::py_class_unary_slot!($class::__next__, *mut $crate::_detail::ffi::PyObject, $crate::py_class::slots::IterNextResultConverter),
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2215,7 +2246,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2228,7 +2259,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_or: $crate::py_class_binary_numeric_slot!($class::__or__),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2245,7 +2276,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2258,7 +2289,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_positive: $crate::py_class_unary_slot!($class::__pos__, *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2294,7 +2325,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2306,7 +2337,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_repr: $crate::py_class_unary_slot!($class::__repr__, *mut $crate::_detail::ffi::PyObject, $crate::_detail::PythonObjectCallbackConverter::<$crate::PyString>(std::marker::PhantomData)),
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2326,7 +2357,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2338,7 +2369,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_richcompare: $crate::py_class_richcompare_slot!($class::__richcmp__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2350,7 +2381,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2362,7 +2393,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_richcompare: $crate::py_class_richcompare_slot!($class::__richcmp__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2374,7 +2405,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2386,7 +2417,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_richcompare: $crate::py_class_richcompare_slot!($class::__richcmp__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2435,7 +2466,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2448,7 +2479,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_rshift: $crate::py_class_binary_numeric_slot!($class::__rshift__),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2483,7 +2514,7 @@ macro_rules! py_class_impl {
     { { def __setitem__(&$slf:ident, $key:ident : Option<&$key_name:ty>, $value:ident : $value_name:ty) -> $res_type:ty { $($body:tt)* } $($tail:tt)* }
         $class:ident $py:ident $info:tt
         /* slots: */ {
-            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt
+            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt
             /* setdelitem */ [
                 sdi_setitem: {},
                 sdi_delitem: $sdi_delitem_slot_value:tt,
@@ -2495,7 +2526,7 @@ macro_rules! py_class_impl {
         { $($tail)* }
         $class $py $info
         /* slots: */ {
-            $type_slots $as_number $as_sequence $as_mapping
+            $type_slots $as_number $as_sequence $as_mapping $as_buffer
             /* setdelitem */ [
                 sdi_setitem: { $crate::py_class_ternary_slot!($class::__setitem__, [Option<&$key_name>], $value_name, $crate::_detail::libc::c_int, $crate::py_class::slots::UnitCallbackConverter) },
                 sdi_delitem: $sdi_delitem_slot_value,
@@ -2510,7 +2541,7 @@ macro_rules! py_class_impl {
     { { def __setitem__(&$slf:ident, $key:ident : &$key_name:ty, $value:ident : $value_name:ty) -> $res_type:ty { $($body:tt)* } $($tail:tt)* }
         $class:ident $py:ident $info:tt
         /* slots: */ {
-            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt
+            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt
             /* setdelitem */ [
                 sdi_setitem: {},
                 sdi_delitem: $sdi_delitem_slot_value:tt,
@@ -2522,7 +2553,7 @@ macro_rules! py_class_impl {
         { $($tail)* }
         $class $py $info
         /* slots: */ {
-            $type_slots $as_number $as_sequence $as_mapping
+            $type_slots $as_number $as_sequence $as_mapping $as_buffer
             /* setdelitem */ [
                 sdi_setitem: { $crate::py_class_ternary_slot!($class::__setitem__, [&$key_name], $value_name, $crate::_detail::libc::c_int, $crate::py_class::slots::UnitCallbackConverter) },
                 sdi_delitem: $sdi_delitem_slot_value,
@@ -2537,7 +2568,7 @@ macro_rules! py_class_impl {
     { { def __setitem__(&$slf:ident, $key:ident : $key_name:ty, $value:ident : $value_name:ty) -> $res_type:ty { $($body:tt)* } $($tail:tt)* }
         $class:ident $py:ident $info:tt
         /* slots: */ {
-            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt
+            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt
             /* setdelitem */ [
                 sdi_setitem: {},
                 sdi_delitem: $sdi_delitem_slot_value:tt,
@@ -2549,7 +2580,7 @@ macro_rules! py_class_impl {
         { $($tail)* }
         $class $py $info
         /* slots: */ {
-            $type_slots $as_number $as_sequence $as_mapping
+            $type_slots $as_number $as_sequence $as_mapping $as_buffer
             /* setdelitem */ [
                 sdi_setitem: { $crate::py_class_ternary_slot!($class::__setitem__, [$key_name], $value_name, $crate::_detail::libc::c_int, $crate::py_class::slots::UnitCallbackConverter) },
                 sdi_delitem: $sdi_delitem_slot_value,
@@ -2569,7 +2600,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2581,7 +2612,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_str: $crate::py_class_unary_slot!($class::__str__, *mut $crate::_detail::ffi::PyObject, $crate::_detail::PythonObjectCallbackConverter::<$crate::PyString>(std::marker::PhantomData)),
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2598,7 +2629,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2611,7 +2642,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_subtract: $crate::py_class_binary_numeric_slot!($class::__sub__),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2636,7 +2667,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2649,7 +2680,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_xor: $crate::py_class_binary_numeric_slot!($class::__xor__),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
diff --git a/src/py_class/py_class_impl3.rs b/src/py_class/py_class_impl3.rs
index d3923ebf..84752357 100644
--- a/src/py_class/py_class_impl3.rs
+++ b/src/py_class/py_class_impl3.rs
@@ -341,7 +341,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -353,7 +353,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_clear: $crate::py_class_tp_clear!($class),
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -370,7 +370,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -383,7 +383,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_absolute: $crate::py_class_unary_slot!($class::__abs__, *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -400,7 +400,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -413,7 +413,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_add: $crate::py_class_binary_numeric_slot!($class::__add__),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -442,7 +442,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -455,7 +455,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_and: $crate::py_class_binary_numeric_slot!($class::__and__),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -476,7 +476,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -489,7 +489,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_bool: $crate::py_class_unary_slot!($class::__bool__, $crate::_detail::libc::c_int, $crate::py_class::slots::BoolConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -501,11 +501,42 @@ macro_rules! py_class_impl {
     { { def __bool__ $($tail:tt)* } $( $stuff:tt )* } => {
         $crate::py_error! { "Invalid signature for operator __bool__" }
     };
+    { { def __buffer__ (&$slf:ident) -> $res_type:ty $body:block $($tail:tt)* }
+        $class:ident $py:ident $info:tt
+        /* slots: */ {
+            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt
+            /* as_buffer */ [
+                bf_getbuffer: {},
+                bf_releasebuffer: {},
+            ]
+            $setdelitem:tt
+        }
+        { $( $imp:item )* }
+        $members:tt $props:tt
+    } => { $crate::py_class_impl! {
+        { $($tail)* }
+        $class $py $info
+        /* slots: */ {
+            $type_slots $as_number $as_sequence $as_mapping
+            /* as_buffer */ [
+                bf_getbuffer: { $crate::py_class_buffer_slot!(bf_getbuffer, $class::__buffer__) },
+                bf_releasebuffer: { $crate::py_class_buffer_slot!(bf_releasebuffer, $class::__buffer__) },
+            ]
+            $setdelitem
+        }
+        /* impl: */ {
+            $($imp)*
+            impl $class {
+                fn __buffer__(&$slf, $py: $crate::Python<'_>) -> $res_type $body
+            }
+        }
+        $members $props
+    }};
     { {  def __call__ (&$slf:ident) -> $res_type:ty { $( $body:tt )* } $($tail:tt)* }
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -517,7 +548,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_call: $crate::py_class_call_slot!{$class::__call__ []},
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -529,7 +560,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -541,7 +572,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_call: $crate::py_argparse_parse_plist_impl!{py_class_call_slot {$class::__call__} [] ($($p)+,)},
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -569,7 +600,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt $as_number:tt
             /* as_sequence */ [ $( $sq_slot_name:ident : $sq_slot_value:expr, )* ]
-            $as_mapping:tt $setdelitem:tt
+            $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -582,7 +613,7 @@ macro_rules! py_class_impl {
                 $( $sq_slot_name : $sq_slot_value, )*
                 sq_contains: $crate::py_class_contains_slot!($class::__contains__, [Option<&$item_name>]),
             ]
-            $as_mapping $setdelitem
+            $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -595,7 +626,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt $as_number:tt
             /* as_sequence */ [ $( $sq_slot_name:ident : $sq_slot_value:expr, )* ]
-            $as_mapping:tt $setdelitem:tt
+            $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -608,7 +639,7 @@ macro_rules! py_class_impl {
                 $( $sq_slot_name : $sq_slot_value, )*
                 sq_contains: $crate::py_class_contains_slot!($class::__contains__, [&$item_name]),
             ]
-            $as_mapping $setdelitem
+            $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -621,7 +652,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt $as_number:tt
             /* as_sequence */ [ $( $sq_slot_name:ident : $sq_slot_value:expr, )* ]
-            $as_mapping:tt $setdelitem:tt
+            $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -634,7 +665,7 @@ macro_rules! py_class_impl {
                 $( $sq_slot_name : $sq_slot_value, )*
                 sq_contains: $crate::py_class_contains_slot!($class::__contains__, [$item_name]),
             ]
-            $as_mapping $setdelitem
+            $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -661,7 +692,7 @@ macro_rules! py_class_impl {
     { { def __delitem__(&$slf:ident, $key:ident : Option<&$key_name:ty>) -> $res_type:ty { $($body:tt)* } $($tail:tt)* }
         $class:ident $py:ident $info:tt
         /* slots: */ {
-            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt
+            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt
             /* setdelitem */ [
                 sdi_setitem: $sdi_setitem_slot_value:tt,
                 sdi_delitem: {},
@@ -673,7 +704,7 @@ macro_rules! py_class_impl {
         { $($tail)* }
         $class $py $info
         /* slots: */ {
-            $type_slots $as_number $as_sequence $as_mapping
+            $type_slots $as_number $as_sequence $as_mapping $as_buffer
             /* setdelitem */ [
                 sdi_setitem: $sdi_setitem_slot_value,
                 sdi_delitem: { $crate::py_class_binary_slot!($class::__delitem__, [Option<&$key_name>], $crate::_detail::libc::c_int, $crate::py_class::slots::UnitCallbackConverter) },
@@ -688,7 +719,7 @@ macro_rules! py_class_impl {
     { { def __delitem__(&$slf:ident, $key:ident : &$key_name:ty) -> $res_type:ty { $($body:tt)* } $($tail:tt)* }
         $class:ident $py:ident $info:tt
         /* slots: */ {
-            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt
+            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt
             /* setdelitem */ [
                 sdi_setitem: $sdi_setitem_slot_value:tt,
                 sdi_delitem: {},
@@ -700,7 +731,7 @@ macro_rules! py_class_impl {
         { $($tail)* }
         $class $py $info
         /* slots: */ {
-            $type_slots $as_number $as_sequence $as_mapping
+            $type_slots $as_number $as_sequence $as_mapping $as_buffer
             /* setdelitem */ [
                 sdi_setitem: $sdi_setitem_slot_value,
                 sdi_delitem: { $crate::py_class_binary_slot!($class::__delitem__, [&$key_name], $crate::_detail::libc::c_int, $crate::py_class::slots::UnitCallbackConverter) },
@@ -715,7 +746,7 @@ macro_rules! py_class_impl {
     { { def __delitem__(&$slf:ident, $key:ident : $key_name:ty) -> $res_type:ty { $($body:tt)* } $($tail:tt)* }
         $class:ident $py:ident $info:tt
         /* slots: */ {
-            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt
+            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt
             /* setdelitem */ [
                 sdi_setitem: $sdi_setitem_slot_value:tt,
                 sdi_delitem: {},
@@ -727,7 +758,7 @@ macro_rules! py_class_impl {
         { $($tail)* }
         $class $py $info
         /* slots: */ {
-            $type_slots $as_number $as_sequence $as_mapping
+            $type_slots $as_number $as_sequence $as_mapping $as_buffer
             /* setdelitem */ [
                 sdi_setitem: $sdi_setitem_slot_value,
                 sdi_delitem: { $crate::py_class_binary_slot!($class::__delitem__, [$key_name], $crate::_detail::libc::c_int, $crate::py_class::slots::UnitCallbackConverter) },
@@ -789,7 +820,7 @@ macro_rules! py_class_impl {
             $type_slots:tt $as_number:tt
             /* as_sequence */ [ $( $sq_slot_name:ident : $sq_slot_value:expr, )* ]
             /* as_mapping */ [ $( $mp_slot_name:ident : $mp_slot_value:expr, )* ]
-            $setdelitem:tt
+            $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -806,7 +837,7 @@ macro_rules! py_class_impl {
                 $( $mp_slot_name : $mp_slot_value, )*
                 mp_subscript: $crate::py_class_binary_slot!($class::__getitem__, [Option<&$key_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $setdelitem
+            $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -820,7 +851,7 @@ macro_rules! py_class_impl {
             $type_slots:tt $as_number:tt
             /* as_sequence */ [ $( $sq_slot_name:ident : $sq_slot_value:expr, )* ]
             /* as_mapping */ [ $( $mp_slot_name:ident : $mp_slot_value:expr, )* ]
-            $setdelitem:tt
+            $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -837,7 +868,7 @@ macro_rules! py_class_impl {
                 $( $mp_slot_name : $mp_slot_value, )*
                 mp_subscript: $crate::py_class_binary_slot!($class::__getitem__, [&$key_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $setdelitem
+            $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -851,7 +882,7 @@ macro_rules! py_class_impl {
             $type_slots:tt $as_number:tt
             /* as_sequence */ [ $( $sq_slot_name:ident : $sq_slot_value:expr, )* ]
             /* as_mapping */ [ $( $mp_slot_name:ident : $mp_slot_value:expr, )* ]
-            $setdelitem:tt
+            $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -868,7 +899,7 @@ macro_rules! py_class_impl {
                 $( $mp_slot_name : $mp_slot_value, )*
                 mp_subscript: $crate::py_class_binary_slot!($class::__getitem__, [$key_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $setdelitem
+            $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -888,7 +919,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -900,7 +931,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_hash: $crate::py_class_unary_slot!($class::__hash__, $crate::Py_hash_t, $crate::py_class::slots::HashConverter),
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -917,7 +948,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -930,7 +961,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_add: $crate::py_class_binary_slot!($class::__iadd__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -943,7 +974,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -956,7 +987,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_add: $crate::py_class_binary_slot!($class::__iadd__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -969,7 +1000,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -982,7 +1013,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_add: $crate::py_class_binary_slot!($class::__iadd__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -999,7 +1030,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1012,7 +1043,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_and: $crate::py_class_binary_slot!($class::__iand__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1025,7 +1056,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1038,7 +1069,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_and: $crate::py_class_binary_slot!($class::__iand__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1051,7 +1082,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1064,7 +1095,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_and: $crate::py_class_binary_slot!($class::__iand__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1085,7 +1116,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1098,7 +1129,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_floor_divide: $crate::py_class_binary_slot!($class::__ifloordiv__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1111,7 +1142,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1124,7 +1155,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_floor_divide: $crate::py_class_binary_slot!($class::__ifloordiv__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1137,7 +1168,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1150,7 +1181,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_floor_divide: $crate::py_class_binary_slot!($class::__ifloordiv__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1167,7 +1198,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1180,7 +1211,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_lshift: $crate::py_class_binary_slot!($class::__ilshift__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1193,7 +1224,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1206,7 +1237,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_lshift: $crate::py_class_binary_slot!($class::__ilshift__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1219,7 +1250,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1232,7 +1263,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_lshift: $crate::py_class_binary_slot!($class::__ilshift__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1249,7 +1280,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1262,7 +1293,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_matrix_multiply: $crate::py_class_binary_slot!($class::__imatmul__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1275,7 +1306,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1288,7 +1319,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_matrix_multiply: $crate::py_class_binary_slot!($class::__imatmul__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1301,7 +1332,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1314,7 +1345,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_matrix_multiply: $crate::py_class_binary_slot!($class::__imatmul__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1331,7 +1362,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1344,7 +1375,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_remainder: $crate::py_class_binary_slot!($class::__imod__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1357,7 +1388,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1370,7 +1401,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_remainder: $crate::py_class_binary_slot!($class::__imod__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1383,7 +1414,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1396,7 +1427,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_remainder: $crate::py_class_binary_slot!($class::__imod__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1413,7 +1444,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1426,7 +1457,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_multiply: $crate::py_class_binary_slot!($class::__imul__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1439,7 +1470,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1452,7 +1483,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_multiply: $crate::py_class_binary_slot!($class::__imul__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1465,7 +1496,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1478,7 +1509,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_multiply: $crate::py_class_binary_slot!($class::__imul__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1511,7 +1542,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1524,7 +1555,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_invert: $crate::py_class_unary_slot!($class::__invert__, *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1541,7 +1572,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1554,7 +1585,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_or: $crate::py_class_binary_slot!($class::__ior__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1567,7 +1598,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1580,7 +1611,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_or: $crate::py_class_binary_slot!($class::__ior__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1593,7 +1624,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1606,7 +1637,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_or: $crate::py_class_binary_slot!($class::__ior__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1627,7 +1658,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1640,7 +1671,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_rshift: $crate::py_class_binary_slot!($class::__irshift__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1653,7 +1684,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1666,7 +1697,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_rshift: $crate::py_class_binary_slot!($class::__irshift__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1679,7 +1710,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1692,7 +1723,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_rshift: $crate::py_class_binary_slot!($class::__irshift__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1709,7 +1740,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1722,7 +1753,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_subtract: $crate::py_class_binary_slot!($class::__isub__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1735,7 +1766,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1748,7 +1779,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_subtract: $crate::py_class_binary_slot!($class::__isub__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1761,7 +1792,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1774,7 +1805,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_subtract: $crate::py_class_binary_slot!($class::__isub__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1790,7 +1821,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1802,7 +1833,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_iter: $crate::py_class_unary_slot!($class::__iter__, *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1819,7 +1850,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1832,7 +1863,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_true_divide: $crate::py_class_binary_slot!($class::__itruediv__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1845,7 +1876,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1858,7 +1889,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_true_divide: $crate::py_class_binary_slot!($class::__itruediv__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1871,7 +1902,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1884,7 +1915,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_true_divide: $crate::py_class_binary_slot!($class::__itruediv__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1901,7 +1932,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1914,7 +1945,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_xor: $crate::py_class_binary_slot!($class::__ixor__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1927,7 +1958,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1940,7 +1971,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_xor: $crate::py_class_binary_slot!($class::__ixor__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1953,7 +1984,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -1966,7 +1997,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_inplace_xor: $crate::py_class_binary_slot!($class::__ixor__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -1988,7 +2019,7 @@ macro_rules! py_class_impl {
             $type_slots:tt $as_number:tt
             /* as_sequence */ [ $( $sq_slot_name:ident : $sq_slot_value:expr, )* ]
             /* as_mapping */ [ $( $mp_slot_name:ident : $mp_slot_value:expr, )* ]
-            $setdelitem:tt
+            $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2005,7 +2036,7 @@ macro_rules! py_class_impl {
                 $( $mp_slot_name : $mp_slot_value, )*
                 mp_length: Some($crate::_detail::ffi::PySequence_Size),
             ]
-            $setdelitem
+            $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2026,7 +2057,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2039,7 +2070,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_lshift: $crate::py_class_binary_numeric_slot!($class::__lshift__),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2068,7 +2099,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2081,7 +2112,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_multiply: $crate::py_class_binary_numeric_slot!($class::__mul__),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2102,7 +2133,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2115,7 +2146,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_negative: $crate::py_class_unary_slot!($class::__neg__, *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2131,7 +2162,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2143,7 +2174,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_new: $crate::py_class_wrap_newfunc!{$class::__new__ []},
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2155,7 +2186,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2167,7 +2198,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_new: $crate::py_argparse_parse_plist_impl!{py_class_wrap_newfunc {$class::__new__} [] ($($p)+,)},
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2182,7 +2213,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2194,7 +2225,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_iternext: $crate::py_class_unary_slot!($class::__next__, *mut $crate::_detail::ffi::PyObject, $crate::py_class::slots::IterNextResultConverter),
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2215,7 +2246,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2228,7 +2259,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_or: $crate::py_class_binary_numeric_slot!($class::__or__),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2245,7 +2276,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2258,7 +2289,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_positive: $crate::py_class_unary_slot!($class::__pos__, *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2294,7 +2325,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2306,7 +2337,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_repr: $crate::py_class_unary_slot!($class::__repr__, *mut $crate::_detail::ffi::PyObject, $crate::_detail::PythonObjectCallbackConverter::<$crate::PyString>(std::marker::PhantomData)),
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2326,7 +2357,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2338,7 +2369,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_richcompare: $crate::py_class_richcompare_slot!($class::__richcmp__, [Option<&$other_name>], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2350,7 +2381,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2362,7 +2393,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_richcompare: $crate::py_class_richcompare_slot!($class::__richcmp__, [&$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2374,7 +2405,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2386,7 +2417,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_richcompare: $crate::py_class_richcompare_slot!($class::__richcmp__, [$other_name], *mut $crate::_detail::ffi::PyObject, $crate::_detail::PyObjectCallbackConverter),
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2435,7 +2466,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2448,7 +2479,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_rshift: $crate::py_class_binary_numeric_slot!($class::__rshift__),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2483,7 +2514,7 @@ macro_rules! py_class_impl {
     { { def __setitem__(&$slf:ident, $key:ident : Option<&$key_name:ty>, $value:ident : $value_name:ty) -> $res_type:ty { $($body:tt)* } $($tail:tt)* }
         $class:ident $py:ident $info:tt
         /* slots: */ {
-            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt
+            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt
             /* setdelitem */ [
                 sdi_setitem: {},
                 sdi_delitem: $sdi_delitem_slot_value:tt,
@@ -2495,7 +2526,7 @@ macro_rules! py_class_impl {
         { $($tail)* }
         $class $py $info
         /* slots: */ {
-            $type_slots $as_number $as_sequence $as_mapping
+            $type_slots $as_number $as_sequence $as_mapping $as_buffer
             /* setdelitem */ [
                 sdi_setitem: { $crate::py_class_ternary_slot!($class::__setitem__, [Option<&$key_name>], $value_name, $crate::_detail::libc::c_int, $crate::py_class::slots::UnitCallbackConverter) },
                 sdi_delitem: $sdi_delitem_slot_value,
@@ -2510,7 +2541,7 @@ macro_rules! py_class_impl {
     { { def __setitem__(&$slf:ident, $key:ident : &$key_name:ty, $value:ident : $value_name:ty) -> $res_type:ty { $($body:tt)* } $($tail:tt)* }
         $class:ident $py:ident $info:tt
         /* slots: */ {
-            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt
+            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt
             /* setdelitem */ [
                 sdi_setitem: {},
                 sdi_delitem: $sdi_delitem_slot_value:tt,
@@ -2522,7 +2553,7 @@ macro_rules! py_class_impl {
         { $($tail)* }
         $class $py $info
         /* slots: */ {
-            $type_slots $as_number $as_sequence $as_mapping
+            $type_slots $as_number $as_sequence $as_mapping $as_buffer
             /* setdelitem */ [
                 sdi_setitem: { $crate::py_class_ternary_slot!($class::__setitem__, [&$key_name], $value_name, $crate::_detail::libc::c_int, $crate::py_class::slots::UnitCallbackConverter) },
                 sdi_delitem: $sdi_delitem_slot_value,
@@ -2537,7 +2568,7 @@ macro_rules! py_class_impl {
     { { def __setitem__(&$slf:ident, $key:ident : $key_name:ty, $value:ident : $value_name:ty) -> $res_type:ty { $($body:tt)* } $($tail:tt)* }
         $class:ident $py:ident $info:tt
         /* slots: */ {
-            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt
+            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt
             /* setdelitem */ [
                 sdi_setitem: {},
                 sdi_delitem: $sdi_delitem_slot_value:tt,
@@ -2549,7 +2580,7 @@ macro_rules! py_class_impl {
         { $($tail)* }
         $class $py $info
         /* slots: */ {
-            $type_slots $as_number $as_sequence $as_mapping
+            $type_slots $as_number $as_sequence $as_mapping $as_buffer
             /* setdelitem */ [
                 sdi_setitem: { $crate::py_class_ternary_slot!($class::__setitem__, [$key_name], $value_name, $crate::_detail::libc::c_int, $crate::py_class::slots::UnitCallbackConverter) },
                 sdi_delitem: $sdi_delitem_slot_value,
@@ -2569,7 +2600,7 @@ macro_rules! py_class_impl {
         $class:ident $py:ident $info:tt
         /* slots: */ {
             /* type_slots */ [ $( $tp_slot_name:ident : $tp_slot_value:expr, )* ]
-            $as_number:tt $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_number:tt $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2581,7 +2612,7 @@ macro_rules! py_class_impl {
                 $( $tp_slot_name : $tp_slot_value, )*
                 tp_str: $crate::py_class_unary_slot!($class::__str__, *mut $crate::_detail::ffi::PyObject, $crate::_detail::PythonObjectCallbackConverter::<$crate::PyString>(std::marker::PhantomData)),
             ]
-            $as_number $as_sequence $as_mapping $setdelitem
+            $as_number $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2598,7 +2629,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2611,7 +2642,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_subtract: $crate::py_class_binary_numeric_slot!($class::__sub__),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
@@ -2636,7 +2667,7 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots:tt
             /* as_number */ [ $( $nb_slot_name:ident : $nb_slot_value:expr, )* ]
-            $as_sequence:tt $as_mapping:tt $setdelitem:tt
+            $as_sequence:tt $as_mapping:tt $as_buffer:tt $setdelitem:tt
         }
         { $( $imp:item )* }
         $members:tt $props:tt
@@ -2649,7 +2680,7 @@ macro_rules! py_class_impl {
                 $( $nb_slot_name : $nb_slot_value, )*
                 nb_xor: $crate::py_class_binary_numeric_slot!($class::__xor__),
             ]
-            $as_sequence $as_mapping $setdelitem
+            $as_sequence $as_mapping $as_buffer $setdelitem
         }
         /* impl: */ {
             $($imp)*
diff --git a/src/py_class/slots.rs b/src/py_class/slots.rs
index ac6e24bd..cb4f5317 100644
--- a/src/py_class/slots.rs
+++ b/src/py_class/slots.rs
@@ -18,8 +18,10 @@
 
 use libc::{c_char, c_int};
 use std::ffi::CString;
+use std::marker::PhantomData;
 use std::{isize, mem, ptr};
 
+use crate::buffer::BufferHandleRaw;
 use crate::conversion::ToPyObject;
 use crate::err::{PyErr, PyResult};
 use crate::exc;
@@ -40,6 +42,7 @@ macro_rules! py_class_type_object_static_init {
         $as_number:tt
         $as_sequence:tt
         $as_mapping:tt
+        $as_buffer:tt
         $setdelitem:tt
     }) => (
         $crate::_detail::ffi::PyTypeObject {
@@ -86,6 +89,7 @@ macro_rules! py_class_type_object_dynamic_init {
             $as_number:tt
             $as_sequence:tt
             $as_mapping:tt
+            $as_buffer:tt
             $setdelitem:tt
         }
         $props:tt
@@ -101,6 +105,7 @@ macro_rules! py_class_type_object_dynamic_init {
         *(unsafe { &mut $type_object.tp_as_sequence }) =
             $crate::py_class_as_sequence!($as_sequence);
         *(unsafe { &mut $type_object.tp_as_number }) = $crate::py_class_as_number!($as_number);
+        *(unsafe { &mut $type_object.tp_as_buffer }) = $crate::py_class_as_buffer!($as_buffer);
         $crate::py_class_as_mapping!($type_object, $as_mapping, $setdelitem);
         *(unsafe { &mut $type_object.tp_getset }) = $crate::py_class_tp_getset!($class, $props);
     };
@@ -184,6 +189,29 @@ macro_rules! py_class_as_number {
     }}
 }
 
+#[macro_export]
+#[doc(hidden)]
+macro_rules! py_class_as_buffer {
+    ([
+        bf_getbuffer: {},
+        bf_releasebuffer: {},
+    ]) => {
+        0 as *mut $crate::_detail::ffi::PyBufferProcs
+    };
+    ([
+        bf_getbuffer: $bf_getbuffer:expr,
+        bf_releasebuffer: $bf_releasebuffer:expr,
+    ]) => {{
+        static mut BUFFER_PROCS: $crate::_detail::ffi::PyBufferProcs =
+            $crate::_detail::ffi::PyBufferProcs {
+                bf_getbuffer: $bf_getbuffer,
+                bf_releasebuffer: $bf_releasebuffer,
+                ..$crate::_detail::ffi::PyBufferProcs_INIT
+            };
+        unsafe { &mut BUFFER_PROCS }
+    }};
+}
+
 #[macro_export]
 #[doc(hidden)]
 macro_rules! py_class_as_mapping {
@@ -538,6 +566,144 @@ macro_rules! py_class_binary_numeric_slot {
     }};
 }
 
+pub struct BufferHandleConverter;
+
+impl CallbackConverter<BufferHandleRaw> for BufferHandleConverter {
+    type R = Option<BufferHandleRaw>;
+
+    #[inline]
+    fn convert(val: BufferHandleRaw, _: Python) -> Option<BufferHandleRaw> {
+        Some(val)
+    }
+
+    #[inline]
+    fn error_value() -> Option<BufferHandleRaw> {
+        None
+    }
+}
+/// This is a bit of a hack to get the actual type of the Rust Buffer from
+/// the py_class's method return type.
+#[doc(hidden)]
+pub struct BufferType<T>(PhantomData<T>);
+impl<T: crate::buffer::BufferHandle> BufferType<T> {
+    #[doc(hidden)]
+    #[inline]
+    pub fn of<C>(_: fn(&C, Python) -> PyResult<T>) -> Self {
+        Self(PhantomData)
+    }
+
+    #[doc(hidden)]
+    #[inline]
+    pub fn assert_same_type(self, _: &T) {}
+
+    #[doc(hidden)]
+    #[inline]
+    pub unsafe fn drop_buffer(self, ptr: *mut libc::c_void) {
+        T::from_owned_void_pointer(ptr);
+    }
+}
+
+#[macro_export]
+#[doc(hidden)]
+macro_rules! py_class_buffer_slot {
+    (bf_getbuffer, $class:ident :: $f:ident) => {{
+        unsafe extern "C" fn getbufferproc(
+            exporter: *mut $crate::_detail::ffi::PyObject,
+            view: *mut $crate::_detail::ffi::Py_buffer,
+            flags: $crate::_detail::libc::c_int,
+        ) -> $crate::_detail::libc::c_int {
+            /*
+                According to https://docs.python.org/3/c-api/typeobj.html#c.PyBufferProcs,
+                the implementation of this function needs to behave like this:
+
+                1. Check if the request can be met. If not, raise PyExc_BufferError,
+                   set view->obj to NULL and return -1.
+                2. Fill in the requested fields.
+                3. Increment an internal counter for the number of exports.
+                4. Set view->obj to exporter and increment view->obj.
+                5. Return 0.
+
+                We handle 1) by trying to get a buffer via the Rust API, and 2) and 4)
+                via `PyBuffer_FillInfo`. Instead of doing 3) by tracking the number of
+                exported buffers in `exporter`, we take ownership of a handle for the
+                buffer and store it in `view.internal`.
+            */
+
+            const LOCATION: &'static str = concat!(stringify!($class), ".", stringify!($f), "()");
+            let res = $crate::_detail::handle_callback(
+                LOCATION,
+                $crate::py_class::slots::BufferHandleConverter,
+                |py| {
+                    let slf = $crate::PyObject::from_borrowed_ptr(py, exporter)
+                        .unchecked_cast_into::<$class>();
+
+                    let buf_handle = slf.__buffer__(py)?;
+
+                    // assert that we are working with the same type as in
+                    // `releasebufferproc`
+                    $crate::py_class::slots::BufferType::of($class::__buffer__)
+                        .assert_same_type(&buf_handle);
+
+                    let buf_handle_raw = $crate::buffer::BufferHandleRaw::new(buf_handle);
+                    Ok(buf_handle_raw)
+                },
+            );
+            match res {
+                None => -1,
+                Some($crate::buffer::BufferHandleRaw { buf, len, owner }) => {
+                    let readonly = 0x1;
+                    let ret = $crate::_detail::ffi::PyBuffer_FillInfo(
+                        view, exporter, buf, len, readonly, flags,
+                    );
+                    if ret == 0 {
+                        (*view).internal = owner;
+                    }
+                    ret
+                }
+            }
+        }
+        Some(getbufferproc)
+    }};
+    (bf_releasebuffer, $class:ident :: $f:ident) => {{
+        unsafe extern "C" fn releasebufferproc(
+            exporter: *mut $crate::_detail::ffi::PyObject,
+            view: *mut $crate::_detail::ffi::Py_buffer,
+        ) {
+            /*
+                According to https://docs.python.org/3/c-api/typeobj.html#c.PyBufferProcs,
+                the implementation of this function needs to (optionally) behave like this:
+
+                1. Decrement an internal counter for the number of exports.
+                2. If the counter is 0, free all memory associated with view.
+
+                However, we are not reference counting the buffer inside the export object,
+                but rather handle this by carrying around a owned handle in `view.internal`,
+                which we drop here again.
+            */
+
+            const LOCATION: &'static str = concat!(stringify!($class), ".", stringify!($f), "()");
+            $crate::_detail::handle_callback(
+                LOCATION,
+                $crate::py_class::slots::UnitCallbackConverter,
+                |py| {
+                    let owner = (*view).internal;
+
+                    // zeroing out the buffer fields should not be needed here,
+                    // but we do so defensivly to catch bugs.
+                    (*view).internal = 0 as *mut _;
+                    (*view).buf = 0 as *mut _;
+                    (*view).len = 0;
+
+                    $crate::py_class::slots::BufferType::of($class::__buffer__).drop_buffer(owner);
+
+                    Ok(())
+                },
+            );
+        }
+        Some(releasebufferproc)
+    }};
+}
+
 pub struct UnitCallbackConverter;
 
 impl CallbackConverter<()> for UnitCallbackConverter {
diff --git a/tests/test_class.rs b/tests/test_class.rs
index b448c5a6..aacb6bb6 100644
--- a/tests/test_class.rs
+++ b/tests/test_class.rs
@@ -1276,3 +1276,150 @@ fn properties() {
     py_run!(py, c, "del c.prop_by_opt_ref");
     py_run!(py, c, "repr(c) == 'P(42, \"testing\" \"DELETED\")'");
 }
+
+#[cfg(feature = "python3-sys")]
+mod py3_only {
+    use self::RefCountLog::*;
+    use super::*;
+    use std::sync::Mutex;
+
+    #[derive(PartialEq, Debug)]
+    enum RefCountLog {
+        Plus,
+        Minus,
+    }
+
+    struct SharedBuffer {
+        buf: Vec<u8>,
+        log: Mutex<Vec<RefCountLog>>,
+    }
+
+    impl SharedBuffer {
+        fn new(buf: Vec<u8>) -> Arc<Self> {
+            Arc::new(SharedBuffer {
+                buf,
+                log: Mutex::new(vec![]),
+            })
+        }
+    }
+
+    struct TestBuffer {
+        ptr: Arc<SharedBuffer>,
+        count_drop: bool,
+    }
+
+    impl TestBuffer {
+        fn new(ptr: &Arc<SharedBuffer>) -> Self {
+            ptr.log.lock().unwrap().push(RefCountLog::Plus);
+            Self::from_arc(ptr.clone())
+        }
+        fn into_arc(mut self) -> Arc<SharedBuffer> {
+            self.count_drop = false;
+            self.ptr.clone()
+        }
+        fn from_arc(ptr: Arc<SharedBuffer>) -> Self {
+            Self {
+                ptr: ptr.clone(),
+                count_drop: true,
+            }
+        }
+    }
+    impl Drop for TestBuffer {
+        fn drop(&mut self) {
+            if self.count_drop {
+                self.ptr.log.lock().unwrap().push(RefCountLog::Minus);
+            }
+        }
+    }
+
+    unsafe impl buffer::BufferHandle for TestBuffer {
+        fn as_bytes(&self) -> &[u8] {
+            &self.ptr.buf
+        }
+        fn to_owned_void_pointer(self) -> *mut libc::c_void {
+            let raw = Arc::into_raw(self.into_arc());
+            assert_eq!(
+                std::mem::size_of::<*mut libc::c_void>(),
+                std::mem::size_of_val(&raw)
+            );
+            raw as *const libc::c_void as *mut libc::c_void
+        }
+        unsafe fn from_owned_void_pointer(ptr: *mut libc::c_void) -> Self {
+            TestBuffer::from_arc(Arc::from_raw(ptr as *const libc::c_void as *const _))
+        }
+    }
+
+    py_class!(class BufferProtocol |py| {
+        data ptr: Arc<SharedBuffer>;
+
+        def __buffer__(&self) -> PyResult<TestBuffer> {
+            Ok(TestBuffer::new(self.ptr(py)))
+        }
+    });
+
+    #[test]
+    fn buffer_protocol() {
+        let gil = Python::acquire_gil();
+        let py = gil.python();
+
+        let buf = SharedBuffer::new(vec![1, 2, 42]);
+        let log_access = buf.clone();
+
+        let c = BufferProtocol::create_instance(py, buf).unwrap();
+
+        macro_rules! check_log {
+            ($($e:expr),+; $($r:expr),+) => {
+                py_run!(py, c, &[$($e),+].join("\n")[..]);
+                {
+                    let should_log = &[$($r),+];
+                    let mut log = log_access.log.lock().unwrap();
+                    assert_eq!(&**log, should_log);
+                    log.clear();
+                }
+            }
+        }
+
+        check_log!("memoryview(c)"; Plus, Minus);
+        check_log!("assert memoryview(c).readonly"; Plus, Minus);
+        check_log!("assert len(memoryview(c)) == 3"; Plus, Minus);
+        check_log!("assert memoryview(c)[0] == 1"; Plus, Minus);
+        check_log!("assert memoryview(c)[2] == 42"; Plus, Minus);
+        check_log!("assert list(memoryview(c)) == [1, 2, 42]"; Plus, Minus);
+        check_log!(
+            "a = memoryview(c)",
+            "b = memoryview(c)",
+            "assert a == b";
+            Plus, Plus, Minus, Minus);
+        check_log!(
+            "a = memoryview(c)",
+            "b = memoryview(a)",
+            "assert a == b";
+            Plus, Minus);
+        check_log!(
+            "def foo(x):",
+            "  a = memoryview(x)",
+            "  assert a[1] == 2",
+            "foo(c)",
+            "foo(c)";
+            Plus, Minus, Plus, Minus);
+        check_log!(
+            "def foo(x):",
+            "  a = memoryview(x)",
+            "  assert a[1] == 2",
+            "foo(c)",
+            "e = memoryview(c)",
+            "f = memoryview(c)",
+            "assert e[2] == f[2] == 42";
+            Plus, Minus, Plus, Plus, Minus, Minus);
+
+        check_log!(
+            "with memoryview(c):",
+            "  pass",
+            "with memoryview(c):",
+            "  pass";
+            Plus, Minus, Plus, Minus);
+
+        py_expect_exception!(py, c, "memoryview(c)[3]", IndexError);
+        py_expect_exception!(py, c, "memoryview(c)[2] = 413", TypeError);
+    }
+}

From 9239342f3c049ee4806b91d15f043d2d14ebd751 Mon Sep 17 00:00:00 2001
From: Marvin Loebel <mloebel@vmray.com>
Date: Mon, 18 May 2020 19:56:03 +0200
Subject: [PATCH 3/6] Remove TODO comment

---
 src/buffer.rs | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/src/buffer.rs b/src/buffer.rs
index a411c67d..7eff330b 100644
--- a/src/buffer.rs
+++ b/src/buffer.rs
@@ -665,11 +665,6 @@ impl_element!(f64, Float);
 ///
 /// It is unsafe because its implementation needs to uphold certain invariants.
 /// See the method docs for more details.
-// TODO:
-// - Buffer request can not fail yet
-// - Buffer can not actually store data inside the object itself, only in a
-//   standalone owned object, which usually means a heap allocated reference counted
-//   container.
 pub unsafe trait BufferHandle: 'static + Send {
     /// Returns the data of `Self` as a continous array of bytes.
     ///

From e4f3d965e3a080138eaa1b1951841357af3f9591 Mon Sep 17 00:00:00 2001
From: Marvin Loebel <mloebel@vmray.com>
Date: Mon, 25 May 2020 11:25:25 +0200
Subject: [PATCH 4/6] Use macro parameter for magic method name

---
 src/py_class/slots.rs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/py_class/slots.rs b/src/py_class/slots.rs
index cb4f5317..08973d67 100644
--- a/src/py_class/slots.rs
+++ b/src/py_class/slots.rs
@@ -637,11 +637,11 @@ macro_rules! py_class_buffer_slot {
                     let slf = $crate::PyObject::from_borrowed_ptr(py, exporter)
                         .unchecked_cast_into::<$class>();
 
-                    let buf_handle = slf.__buffer__(py)?;
+                    let buf_handle = slf.$f(py)?;
 
                     // assert that we are working with the same type as in
                     // `releasebufferproc`
-                    $crate::py_class::slots::BufferType::of($class::__buffer__)
+                    $crate::py_class::slots::BufferType::of($class::$f)
                         .assert_same_type(&buf_handle);
 
                     let buf_handle_raw = $crate::buffer::BufferHandleRaw::new(buf_handle);
@@ -694,7 +694,7 @@ macro_rules! py_class_buffer_slot {
                     (*view).buf = 0 as *mut _;
                     (*view).len = 0;
 
-                    $crate::py_class::slots::BufferType::of($class::__buffer__).drop_buffer(owner);
+                    $crate::py_class::slots::BufferType::of($class::$f).drop_buffer(owner);
 
                     Ok(())
                 },

From a1cd84c6f399f954014b89f3b883b34313d43825 Mon Sep 17 00:00:00 2001
From: Marvin Loebel <mloebel@vmray.com>
Date: Mon, 25 May 2020 20:38:36 +0200
Subject: [PATCH 5/6] Add alternative API "__direct_buffer__" for consumers
 that can not handle releasable PyBuffers

---
 src/buffer.rs                  | 13 +++++--
 src/py_class/py_class_impl.py  | 30 +++++++++++-----
 src/py_class/py_class_impl2.rs | 31 ----------------
 src/py_class/py_class_impl3.rs | 35 ++++++++++++++++--
 src/py_class/slots.rs          | 65 ++++++++++++++++++++++++++++++++--
 tests/test_class.rs            | 61 ++++++++++++++++++++++++++++++-
 6 files changed, 187 insertions(+), 48 deletions(-)

diff --git a/src/buffer.rs b/src/buffer.rs
index 7eff330b..68f2d9e5 100644
--- a/src/buffer.rs
+++ b/src/buffer.rs
@@ -18,7 +18,7 @@
 
 use libc;
 use std::ffi::CStr;
-use std::{cell, mem, slice};
+use std::{cell, mem, ptr, slice};
 
 use crate::err::{self, PyResult};
 use crate::exc;
@@ -701,13 +701,22 @@ pub struct BufferHandleRaw {
 impl BufferHandleRaw {
     #[doc(hidden)]
     #[inline]
-    pub unsafe fn new<T: BufferHandle>(handle: T) -> Self {
+    pub unsafe fn new_owned<T: BufferHandle>(handle: T) -> Self {
         let slice = handle.as_bytes();
         let buf = slice.as_ptr() as *mut libc::c_void;
         let len = slice.len() as crate::Py_ssize_t;
         let owner = handle.to_owned_void_pointer();
         Self { buf, len, owner }
     }
+
+    #[doc(hidden)]
+    #[inline]
+    pub unsafe fn new_borrowed(slice: &[u8]) -> Self {
+        let buf = slice.as_ptr() as *mut libc::c_void;
+        let len = slice.len() as crate::Py_ssize_t;
+        let owner = ptr::null_mut();
+        Self { buf, len, owner }
+    }
 }
 
 #[cfg(test)]
diff --git a/src/py_class/py_class_impl.py b/src/py_class/py_class_impl.py
index 6aee72ce..131a916a 100644
--- a/src/py_class/py_class_impl.py
+++ b/src/py_class/py_class_impl.py
@@ -725,17 +725,28 @@ def inplace_numeric_operator(special_name, slot):
              args=[Argument('other')])(special_name)
 
 @special_method
-def buffer_protocol(special_name, enabled):
+def buffer_protocol(special_name, enabled, mode):
     if enabled:
-        pattern = 'def %s (&$slf:ident) -> $res_type:ty $body:block' % special_name
+        if mode == "direct":
+            pattern = 'def %s <$gil_lt:lifetime>(&$slf_lt:lifetime $slf:ident) -> $res_type:ty $body:block' % special_name
+            new_impl='''
+                impl $class {
+                    fn %s<$gil_lt>(&$slf_lt $slf, $py: $crate::Python<$gil_lt>) -> $res_type $body
+                }
+            ''' % special_name
+
+        if mode == "handle":
+            pattern = 'def %s (&$slf:ident) -> $res_type:ty $body:block' % special_name
+            new_impl='''
+                impl $class {
+                    fn %s(&$slf, $py: $crate::Python<'_>) -> $res_type $body
+                }
+            ''' % special_name
+
         new_slots = []
         for slot in ['bf_getbuffer', 'bf_releasebuffer']:
-            new_slots.append((slot, '$crate::py_class_buffer_slot!(%s, $class::%s)' % (slot, special_name)))
-        generate_case(pattern, new_slots=new_slots, new_impl='''
-            impl $class {
-                fn %s(&$slf, $py: $crate::Python<'_>) -> $res_type $body
-            }
-        ''' % special_name)
+            new_slots.append((slot, '$crate::py_class_buffer_slot!(%s, %s, $class::%s)' % (mode, slot, special_name)))
+        generate_case(pattern, new_slots=new_slots, new_impl=new_impl)
 
 special_names = {
     '__init__': error('__init__ is not supported by py_class!; use __new__ instead.'),
@@ -886,7 +897,8 @@ def buffer_protocol(special_name, enabled):
     '__aexit__': unimplemented(),
 
     # Buffer protocol
-    '__buffer__': buffer_protocol(not PY2),
+    '__buffer__': buffer_protocol(not PY2, "handle"),
+    '__direct_buffer__': buffer_protocol(not PY2, "direct"),
 }
 
 def main():
diff --git a/src/py_class/py_class_impl2.rs b/src/py_class/py_class_impl2.rs
index 975676dc..a166116a 100644
--- a/src/py_class/py_class_impl2.rs
+++ b/src/py_class/py_class_impl2.rs
@@ -501,37 +501,6 @@ macro_rules! py_class_impl {
     { { def __bool__ $($tail:tt)* } $( $stuff:tt )* } => {
         $crate::py_error! { "Invalid signature for operator __bool__" }
     };
-    { { def __buffer__ (&$slf:ident) -> $res_type:ty $body:block $($tail:tt)* }
-        $class:ident $py:ident $info:tt
-        /* slots: */ {
-            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt
-            /* as_buffer */ [
-                bf_getbuffer: {},
-                bf_releasebuffer: {},
-            ]
-            $setdelitem:tt
-        }
-        { $( $imp:item )* }
-        $members:tt $props:tt
-    } => { $crate::py_class_impl! {
-        { $($tail)* }
-        $class $py $info
-        /* slots: */ {
-            $type_slots $as_number $as_sequence $as_mapping
-            /* as_buffer */ [
-                bf_getbuffer: { $crate::py_class_buffer_slot!(bf_getbuffer, $class::__buffer__) },
-                bf_releasebuffer: { $crate::py_class_buffer_slot!(bf_releasebuffer, $class::__buffer__) },
-            ]
-            $setdelitem
-        }
-        /* impl: */ {
-            $($imp)*
-            impl $class {
-                fn __buffer__(&$slf, $py: $crate::Python<'_>) -> $res_type $body
-            }
-        }
-        $members $props
-    }};
     { {  def __call__ (&$slf:ident) -> $res_type:ty { $( $body:tt )* } $($tail:tt)* }
         $class:ident $py:ident $info:tt
         /* slots: */ {
diff --git a/src/py_class/py_class_impl3.rs b/src/py_class/py_class_impl3.rs
index 84752357..9fcbcfe5 100644
--- a/src/py_class/py_class_impl3.rs
+++ b/src/py_class/py_class_impl3.rs
@@ -519,8 +519,8 @@ macro_rules! py_class_impl {
         /* slots: */ {
             $type_slots $as_number $as_sequence $as_mapping
             /* as_buffer */ [
-                bf_getbuffer: { $crate::py_class_buffer_slot!(bf_getbuffer, $class::__buffer__) },
-                bf_releasebuffer: { $crate::py_class_buffer_slot!(bf_releasebuffer, $class::__buffer__) },
+                bf_getbuffer: { $crate::py_class_buffer_slot!(handle, bf_getbuffer, $class::__buffer__) },
+                bf_releasebuffer: { $crate::py_class_buffer_slot!(handle, bf_releasebuffer, $class::__buffer__) },
             ]
             $setdelitem
         }
@@ -778,6 +778,37 @@ macro_rules! py_class_impl {
     { { def __dir__ $($tail:tt)* } $( $stuff:tt )* } => {
         $crate::py_error! { "__dir__ is not supported by py_class! yet." }
     };
+    { { def __direct_buffer__ <$gil_lt:lifetime>(&$slf_lt:lifetime $slf:ident) -> $res_type:ty $body:block $($tail:tt)* }
+        $class:ident $py:ident $info:tt
+        /* slots: */ {
+            $type_slots:tt $as_number:tt $as_sequence:tt $as_mapping:tt
+            /* as_buffer */ [
+                bf_getbuffer: {},
+                bf_releasebuffer: {},
+            ]
+            $setdelitem:tt
+        }
+        { $( $imp:item )* }
+        $members:tt $props:tt
+    } => { $crate::py_class_impl! {
+        { $($tail)* }
+        $class $py $info
+        /* slots: */ {
+            $type_slots $as_number $as_sequence $as_mapping
+            /* as_buffer */ [
+                bf_getbuffer: { $crate::py_class_buffer_slot!(direct, bf_getbuffer, $class::__direct_buffer__) },
+                bf_releasebuffer: { $crate::py_class_buffer_slot!(direct, bf_releasebuffer, $class::__direct_buffer__) },
+            ]
+            $setdelitem
+        }
+        /* impl: */ {
+            $($imp)*
+            impl $class {
+                fn __direct_buffer__<$gil_lt>(&$slf_lt $slf, $py: $crate::Python<$gil_lt>) -> $res_type $body
+            }
+        }
+        $members $props
+    }};
 
     { { def __div__ $($tail:tt)* } $( $stuff:tt )* } => {
         $crate::py_error! { "__div__ is not supported by py_class! yet." }
diff --git a/src/py_class/slots.rs b/src/py_class/slots.rs
index 08973d67..7d8eb978 100644
--- a/src/py_class/slots.rs
+++ b/src/py_class/slots.rs
@@ -30,6 +30,7 @@ use crate::function::CallbackConverter;
 use crate::objects::PyObject;
 use crate::py_class::CompareOp;
 use crate::python::{Python, PythonObject};
+use crate::PySharedRef;
 use crate::Py_hash_t;
 
 #[macro_export]
@@ -603,10 +604,14 @@ impl<T: crate::buffer::BufferHandle> BufferType<T> {
     }
 }
 
+#[doc(hidden)]
+#[inline]
+pub fn assert_buffer_type_direct<C>(_: for<'a> fn(&'a C, Python<'a>) -> PyResult<&'a [u8]>) {}
+
 #[macro_export]
 #[doc(hidden)]
 macro_rules! py_class_buffer_slot {
-    (bf_getbuffer, $class:ident :: $f:ident) => {{
+    (handle, bf_getbuffer, $class:ident :: $f:ident) => {{
         unsafe extern "C" fn getbufferproc(
             exporter: *mut $crate::_detail::ffi::PyObject,
             view: *mut $crate::_detail::ffi::Py_buffer,
@@ -644,7 +649,7 @@ macro_rules! py_class_buffer_slot {
                     $crate::py_class::slots::BufferType::of($class::$f)
                         .assert_same_type(&buf_handle);
 
-                    let buf_handle_raw = $crate::buffer::BufferHandleRaw::new(buf_handle);
+                    let buf_handle_raw = $crate::buffer::BufferHandleRaw::new_owned(buf_handle);
                     Ok(buf_handle_raw)
                 },
             );
@@ -664,7 +669,7 @@ macro_rules! py_class_buffer_slot {
         }
         Some(getbufferproc)
     }};
-    (bf_releasebuffer, $class:ident :: $f:ident) => {{
+    (handle, bf_releasebuffer, $class:ident :: $f:ident) => {{
         unsafe extern "C" fn releasebufferproc(
             exporter: *mut $crate::_detail::ffi::PyObject,
             view: *mut $crate::_detail::ffi::Py_buffer,
@@ -702,6 +707,60 @@ macro_rules! py_class_buffer_slot {
         }
         Some(releasebufferproc)
     }};
+    (direct, bf_getbuffer, $class:ident :: $f:ident) => {{
+        unsafe extern "C" fn getbufferproc(
+            exporter: *mut $crate::_detail::ffi::PyObject,
+            view: *mut $crate::_detail::ffi::Py_buffer,
+            flags: $crate::_detail::libc::c_int,
+        ) -> $crate::_detail::libc::c_int {
+            /*
+                According to https://docs.python.org/3/c-api/typeobj.html#c.PyBufferProcs,
+                the implementation of this function needs to behave like this:
+
+                1. Check if the request can be met. If not, raise PyExc_BufferError,
+                   set view->obj to NULL and return -1.
+                2. Fill in the requested fields.
+                3. Increment an internal counter for the number of exports.
+                4. Set view->obj to exporter and increment view->obj.
+                5. Return 0.
+
+                We handle 1) by trying to get a buffer via the Rust API, and 2) and 4)
+                via `PyBuffer_FillInfo`. Instead of doing 3) by tracking the number of
+                exported buffers in `exporter`, we just do nothing.
+            */
+
+            const LOCATION: &'static str = concat!(stringify!($class), ".", stringify!($f), "()");
+            let res = $crate::_detail::handle_callback(
+                LOCATION,
+                $crate::py_class::slots::BufferHandleConverter,
+                |py| {
+                    let slf = $crate::PyObject::from_borrowed_ptr(py, exporter)
+                        .unchecked_cast_into::<$class>();
+
+                    // assert that we are borrowing bytes from the refcounted $class object
+                    $crate::py_class::slots::assert_buffer_type_direct($class::$f);
+
+                    let buf_slice = slf.$f(py)?;
+
+                    let buf_handle_raw = $crate::buffer::BufferHandleRaw::new_borrowed(buf_slice);
+                    Ok(buf_handle_raw)
+                },
+            );
+            match res {
+                None => -1,
+                Some($crate::buffer::BufferHandleRaw { buf, len, owner }) => {
+                    let readonly = 0x1;
+                    $crate::_detail::ffi::PyBuffer_FillInfo(
+                        view, exporter, buf, len, readonly, flags,
+                    )
+                }
+            }
+        }
+        Some(getbufferproc)
+    }};
+    (direct, bf_releasebuffer, $class:ident :: $f:ident) => {{
+        None
+    }};
 }
 
 pub struct UnitCallbackConverter;
diff --git a/tests/test_class.rs b/tests/test_class.rs
index aacb6bb6..7e2074e7 100644
--- a/tests/test_class.rs
+++ b/tests/test_class.rs
@@ -1358,7 +1358,7 @@ mod py3_only {
     });
 
     #[test]
-    fn buffer_protocol() {
+    fn test_buffer() {
         let gil = Python::acquire_gil();
         let py = gil.python();
 
@@ -1422,4 +1422,63 @@ mod py3_only {
         py_expect_exception!(py, c, "memoryview(c)[3]", IndexError);
         py_expect_exception!(py, c, "memoryview(c)[2] = 413", TypeError);
     }
+
+    py_class!(class DirectBufferProtocol |py| {
+        data ptr: Arc<Vec<u8>>;
+
+        def __direct_buffer__<'a>(&'a self) -> PyResult<&'a [u8]> {
+            Ok(self.ptr(py))
+        }
+    });
+
+    #[test]
+    fn test_direct_buffer() {
+        let gil = Python::acquire_gil();
+        let py = gil.python();
+
+        let buf = Arc::new(vec![1, 2, 42]);
+
+        let c = DirectBufferProtocol::create_instance(py, buf).unwrap();
+
+        macro_rules! check_log {
+            ($($e:expr),+) => {
+                py_run!(py, c, &[$($e),+].join("\n")[..]);
+            }
+        }
+
+        check_log!("memoryview(c)");
+        check_log!("assert memoryview(c).readonly");
+        check_log!("assert len(memoryview(c)) == 3");
+        check_log!("assert memoryview(c)[0] == 1");
+        check_log!("assert memoryview(c)[2] == 42");
+        check_log!("assert list(memoryview(c)) == [1, 2, 42]");
+        check_log!("a = memoryview(c)", "b = memoryview(c)", "assert a == b");
+        check_log!("a = memoryview(c)", "b = memoryview(a)", "assert a == b");
+        check_log!(
+            "def foo(x):",
+            "  a = memoryview(x)",
+            "  assert a[1] == 2",
+            "foo(c)",
+            "foo(c)"
+        );
+        check_log!(
+            "def foo(x):",
+            "  a = memoryview(x)",
+            "  assert a[1] == 2",
+            "foo(c)",
+            "e = memoryview(c)",
+            "f = memoryview(c)",
+            "assert e[2] == f[2] == 42"
+        );
+
+        check_log!(
+            "with memoryview(c):",
+            "  pass",
+            "with memoryview(c):",
+            "  pass"
+        );
+
+        py_expect_exception!(py, c, "memoryview(c)[3]", IndexError);
+        py_expect_exception!(py, c, "memoryview(c)[2] = 413", TypeError);
+    }
 }

From 2e243f7622a8d33bca3fb321db25d4be4c26397d Mon Sep 17 00:00:00 2001
From: Marvin Loebel <mloebel@vmray.com>
Date: Thu, 28 May 2020 10:46:13 +0200
Subject: [PATCH 6/6] Changed consuming `to_...` method name to `into_...`.
 Also moved slots.rs specific data structures into the same module.

---
 src/buffer.rs         | 30 +-----------------------------
 src/py_class/slots.rs | 40 +++++++++++++++++++++++++++++++++++-----
 tests/test_class.rs   |  2 +-
 3 files changed, 37 insertions(+), 35 deletions(-)

diff --git a/src/buffer.rs b/src/buffer.rs
index 68f2d9e5..a268234b 100644
--- a/src/buffer.rs
+++ b/src/buffer.rs
@@ -680,7 +680,7 @@ pub unsafe trait BufferHandle: 'static + Send {
     ///
     /// The returned pointer has to be a valid pointer that
     /// can be converted back to `Self`.
-    fn to_owned_void_pointer(self) -> *mut libc::c_void;
+    fn into_owned_void_pointer(self) -> *mut libc::c_void;
 
     /// Convert an owned void pointer back to `Self`. This takes owenrship of the pointer.
     ///
@@ -691,34 +691,6 @@ pub unsafe trait BufferHandle: 'static + Send {
     unsafe fn from_owned_void_pointer(ptr: *mut libc::c_void) -> Self;
 }
 
-#[doc(hidden)]
-pub struct BufferHandleRaw {
-    pub buf: *mut libc::c_void,
-    pub len: crate::Py_ssize_t,
-    pub owner: *mut libc::c_void,
-}
-
-impl BufferHandleRaw {
-    #[doc(hidden)]
-    #[inline]
-    pub unsafe fn new_owned<T: BufferHandle>(handle: T) -> Self {
-        let slice = handle.as_bytes();
-        let buf = slice.as_ptr() as *mut libc::c_void;
-        let len = slice.len() as crate::Py_ssize_t;
-        let owner = handle.to_owned_void_pointer();
-        Self { buf, len, owner }
-    }
-
-    #[doc(hidden)]
-    #[inline]
-    pub unsafe fn new_borrowed(slice: &[u8]) -> Self {
-        let buf = slice.as_ptr() as *mut libc::c_void;
-        let len = slice.len() as crate::Py_ssize_t;
-        let owner = ptr::null_mut();
-        Self { buf, len, owner }
-    }
-}
-
 #[cfg(test)]
 mod test {
     use super::PyBuffer;
diff --git a/src/py_class/slots.rs b/src/py_class/slots.rs
index 7d8eb978..cb25091f 100644
--- a/src/py_class/slots.rs
+++ b/src/py_class/slots.rs
@@ -21,7 +21,7 @@ use std::ffi::CString;
 use std::marker::PhantomData;
 use std::{isize, mem, ptr};
 
-use crate::buffer::BufferHandleRaw;
+use crate::buffer::BufferHandle;
 use crate::conversion::ToPyObject;
 use crate::err::{PyErr, PyResult};
 use crate::exc;
@@ -567,6 +567,34 @@ macro_rules! py_class_binary_numeric_slot {
     }};
 }
 
+#[doc(hidden)]
+pub struct BufferHandleRaw {
+    pub buf: *mut libc::c_void,
+    pub len: crate::Py_ssize_t,
+    pub owner: *mut libc::c_void,
+}
+
+impl BufferHandleRaw {
+    #[doc(hidden)]
+    #[inline]
+    pub unsafe fn new_owned<T: BufferHandle>(handle: T) -> Self {
+        let slice = handle.as_bytes();
+        let buf = slice.as_ptr() as *mut libc::c_void;
+        let len = slice.len() as crate::Py_ssize_t;
+        let owner = handle.into_owned_void_pointer();
+        Self { buf, len, owner }
+    }
+
+    #[doc(hidden)]
+    #[inline]
+    pub unsafe fn new_borrowed(slice: &[u8]) -> Self {
+        let buf = slice.as_ptr() as *mut libc::c_void;
+        let len = slice.len() as crate::Py_ssize_t;
+        let owner = ptr::null_mut();
+        Self { buf, len, owner }
+    }
+}
+
 pub struct BufferHandleConverter;
 
 impl CallbackConverter<BufferHandleRaw> for BufferHandleConverter {
@@ -649,13 +677,14 @@ macro_rules! py_class_buffer_slot {
                     $crate::py_class::slots::BufferType::of($class::$f)
                         .assert_same_type(&buf_handle);
 
-                    let buf_handle_raw = $crate::buffer::BufferHandleRaw::new_owned(buf_handle);
+                    let buf_handle_raw =
+                        $crate::py_class::slots::BufferHandleRaw::new_owned(buf_handle);
                     Ok(buf_handle_raw)
                 },
             );
             match res {
                 None => -1,
-                Some($crate::buffer::BufferHandleRaw { buf, len, owner }) => {
+                Some($crate::py_class::slots::BufferHandleRaw { buf, len, owner }) => {
                     let readonly = 0x1;
                     let ret = $crate::_detail::ffi::PyBuffer_FillInfo(
                         view, exporter, buf, len, readonly, flags,
@@ -742,13 +771,14 @@ macro_rules! py_class_buffer_slot {
 
                     let buf_slice = slf.$f(py)?;
 
-                    let buf_handle_raw = $crate::buffer::BufferHandleRaw::new_borrowed(buf_slice);
+                    let buf_handle_raw =
+                        $crate::py_class::slots::BufferHandleRaw::new_borrowed(buf_slice);
                     Ok(buf_handle_raw)
                 },
             );
             match res {
                 None => -1,
-                Some($crate::buffer::BufferHandleRaw { buf, len, owner }) => {
+                Some($crate::py_class::slots::BufferHandleRaw { buf, len, owner }) => {
                     let readonly = 0x1;
                     $crate::_detail::ffi::PyBuffer_FillInfo(
                         view, exporter, buf, len, readonly, flags,
diff --git a/tests/test_class.rs b/tests/test_class.rs
index 7e2074e7..a3233395 100644
--- a/tests/test_class.rs
+++ b/tests/test_class.rs
@@ -1336,7 +1336,7 @@ mod py3_only {
         fn as_bytes(&self) -> &[u8] {
             &self.ptr.buf
         }
-        fn to_owned_void_pointer(self) -> *mut libc::c_void {
+        fn into_owned_void_pointer(self) -> *mut libc::c_void {
             let raw = Arc::into_raw(self.into_arc());
             assert_eq!(
                 std::mem::size_of::<*mut libc::c_void>(),