gh-99202: Fix extension type from documentation for compiling in C++20 mode (#102518)

Author: jpn--

Doc/extending/newtypes_tutorial.rst

@@ -88,7 +88,7 @@ standard Python floats::
 The second bit is the definition of the type object. ::
 
    static PyTypeObject CustomType = {
-       PyVarObject_HEAD_INIT(NULL, 0)
+       .ob_base = PyVarObject_HEAD_INIT(NULL, 0)
        .tp_name = "custom.Custom",
        .tp_doc = PyDoc_STR("Custom objects"),
        .tp_basicsize = sizeof(CustomObject),
@@ -109,7 +109,7 @@ common practice to not specify them explicitly unless you need them.
 
 We're going to pick it apart, one field at a time::
 
-   PyVarObject_HEAD_INIT(NULL, 0)
+   .ob_base = PyVarObject_HEAD_INIT(NULL, 0)
 
 This line is mandatory boilerplate to initialize the ``ob_base``
 field mentioned above. ::

Doc/includes/custom.c

@@ -7,7 +7,7 @@ typedef struct {
 } CustomObject;
 
 static PyTypeObject CustomType = {
-    PyVarObject_HEAD_INIT(NULL, 0)
+    .ob_base = PyVarObject_HEAD_INIT(NULL, 0)
     .tp_name = "custom.Custom",
     .tp_doc = PyDoc_STR("Custom objects"),
     .tp_basicsize = sizeof(CustomObject),
@@ -17,7 +17,7 @@ static PyTypeObject CustomType = {
 };
 
 static PyModuleDef custommodule = {
-    PyModuleDef_HEAD_INIT,
+    .m_base = PyModuleDef_HEAD_INIT,
     .m_name = "custom",
     .m_doc = "Example module that creates an extension type.",
     .m_size = -1,

Doc/includes/custom2.c

@@ -90,7 +90,7 @@ static PyMethodDef Custom_methods[] = {
 };
 
 static PyTypeObject CustomType = {
-    PyVarObject_HEAD_INIT(NULL, 0)
+    .ob_base = PyVarObject_HEAD_INIT(NULL, 0)
     .tp_name = "custom2.Custom",
     .tp_doc = PyDoc_STR("Custom objects"),
     .tp_basicsize = sizeof(CustomObject),
@@ -104,7 +104,7 @@ static PyTypeObject CustomType = {
 };
 
 static PyModuleDef custommodule = {
-    PyModuleDef_HEAD_INIT,
+    .m_base =PyModuleDef_HEAD_INIT,
     .m_name = "custom2",
     .m_doc = "Example module that creates an extension type.",
     .m_size = -1,

Doc/includes/custom3.c

@@ -130,7 +130,7 @@ static PyMethodDef Custom_methods[] = {
 };
 
 static PyTypeObject CustomType = {
-    PyVarObject_HEAD_INIT(NULL, 0)
+    .ob_base = PyVarObject_HEAD_INIT(NULL, 0)
     .tp_name = "custom3.Custom",
     .tp_doc = PyDoc_STR("Custom objects"),
     .tp_basicsize = sizeof(CustomObject),
@@ -145,7 +145,7 @@ static PyTypeObject CustomType = {
 };
 
 static PyModuleDef custommodule = {
-    PyModuleDef_HEAD_INIT,
+    .m_base = PyModuleDef_HEAD_INIT,
     .m_name = "custom3",
     .m_doc = "Example module that creates an extension type.",
     .m_size = -1,

Doc/includes/custom4.c

@@ -146,7 +146,7 @@ static PyMethodDef Custom_methods[] = {
 };
 
 static PyTypeObject CustomType = {
-    PyVarObject_HEAD_INIT(NULL, 0)
+    .ob_base = PyVarObject_HEAD_INIT(NULL, 0)
     .tp_name = "custom4.Custom",
     .tp_doc = PyDoc_STR("Custom objects"),
     .tp_basicsize = sizeof(CustomObject),
@@ -163,7 +163,7 @@ static PyTypeObject CustomType = {
 };
 
 static PyModuleDef custommodule = {
-    PyModuleDef_HEAD_INIT,
+    .m_base = PyModuleDef_HEAD_INIT,
     .m_name = "custom4",
     .m_doc = "Example module that creates an extension type.",
     .m_size = -1,

Misc/NEWS.d/next/Documentation/2023-03-07-23-30-29.gh-issue-99202.hhiAJF.rst

@@ -0,0 +1 @@
+Fix extension type from documentation for compiling in C++20 mode