Add some standard zend interfaces (#164)

* Add some standard zend interfaces

The zend API also has some standard interfaces it exposes:
https://github.com/php/php-src/blob/c8c09b4aaee7ac447828564c6267e62eb304135b/Zend/zend_interfaces.h#L27-L33
```
extern ZEND_API zend_class_entry *zend_ce_traversable;
extern ZEND_API zend_class_entry *zend_ce_aggregate;
extern ZEND_API zend_class_entry *zend_ce_iterator;
extern ZEND_API zend_class_entry *zend_ce_arrayaccess;
extern ZEND_API zend_class_entry *zend_ce_serializable;
extern ZEND_API zend_class_entry *zend_ce_countable;
extern ZEND_API zend_class_entry *zend_ce_stringable;
```

This surfaced in #163 and should make it possible to implement these interfaces.

* Add some links to the php documentation

* update docs.rs bindings

Co-authored-by: David Cole <[email protected]>

Author: nikeee

allowed_bindings.rs

@@ -49,6 +49,13 @@ bind! {
     zend_ce_type_error,
     zend_ce_unhandled_match_error,
     zend_ce_value_error,
+    zend_ce_traversable,
+    zend_ce_aggregate,
+    zend_ce_iterator,
+    zend_ce_arrayaccess,
+    zend_ce_serializable,
+    zend_ce_countable,
+    zend_ce_stringable,
     zend_class_entry,
     zend_declare_class_constant,
     zend_declare_property,

docsrs_bindings.rs

@@ -1405,3 +1405,24 @@ extern "C" {
 extern "C" {
     pub fn zend_do_implement_interface(ce: *mut zend_class_entry, iface: *mut zend_class_entry);
 }
+extern "C" {
+    pub static mut zend_ce_traversable: *mut zend_class_entry;
+}
+extern "C" {
+    pub static mut zend_ce_aggregate: *mut zend_class_entry;
+}
+extern "C" {
+    pub static mut zend_ce_iterator: *mut zend_class_entry;
+}
+extern "C" {
+    pub static mut zend_ce_arrayaccess: *mut zend_class_entry;
+}
+extern "C" {
+    pub static mut zend_ce_serializable: *mut zend_class_entry;
+}
+extern "C" {
+    pub static mut zend_ce_countable: *mut zend_class_entry;
+}
+extern "C" {
+    pub static mut zend_ce_stringable: *mut zend_class_entry;
+}

src/zend/ce.rs

@@ -3,70 +3,107 @@
 #![allow(clippy::unwrap_used)]
 
 use crate::ffi::{
-    zend_ce_argument_count_error, zend_ce_arithmetic_error, zend_ce_compile_error,
-    zend_ce_division_by_zero_error, zend_ce_error_exception, zend_ce_exception,
-    zend_ce_parse_error, zend_ce_throwable, zend_ce_type_error, zend_ce_unhandled_match_error,
-    zend_ce_value_error, zend_standard_class_def,
+    zend_ce_aggregate, zend_ce_argument_count_error, zend_ce_arithmetic_error, zend_ce_arrayaccess,
+    zend_ce_compile_error, zend_ce_countable, zend_ce_division_by_zero_error,
+    zend_ce_error_exception, zend_ce_exception, zend_ce_iterator, zend_ce_parse_error,
+    zend_ce_serializable, zend_ce_stringable, zend_ce_throwable, zend_ce_traversable,
+    zend_ce_type_error, zend_ce_unhandled_match_error, zend_ce_value_error,
+    zend_standard_class_def,
 };
 
 use super::ClassEntry;
 
-/// Returns the base `stdClass` class.
+/// Returns the base [`stdClass`](https://www.php.net/manual/en/class.stdclass.php) class.
 pub fn stdclass() -> &'static ClassEntry {
     unsafe { zend_standard_class_def.as_ref() }.unwrap()
 }
 
-/// Returns the base `Throwable` class.
+/// Returns the base [`Throwable`](https://www.php.net/manual/en/class.throwable.php) class.
 pub fn throwable() -> &'static ClassEntry {
     unsafe { zend_ce_throwable.as_ref() }.unwrap()
 }
 
-/// Returns the base `Exception` class.
+/// Returns the base [`Exception`](https://www.php.net/manual/en/class.exception.php) class.
 pub fn exception() -> &'static ClassEntry {
     unsafe { zend_ce_exception.as_ref() }.unwrap()
 }
 
-/// Returns the base `ErrorException` class.
+/// Returns the base [`ErrorException`](https://www.php.net/manual/en/class.errorexception.php) class.
 pub fn error_exception() -> &'static ClassEntry {
     unsafe { zend_ce_error_exception.as_ref() }.unwrap()
 }
 
-/// Returns the base `CompileError` class.
+/// Returns the base [`CompileError`](https://www.php.net/manual/en/class.compileerror.php) class.
 pub fn compile_error() -> &'static ClassEntry {
     unsafe { zend_ce_compile_error.as_ref() }.unwrap()
 }
 
-/// Returns the base `ParseError` class.
+/// Returns the base [`ParseError`](https://www.php.net/manual/en/class.parseerror.php) class.
 pub fn parse_error() -> &'static ClassEntry {
     unsafe { zend_ce_parse_error.as_ref() }.unwrap()
 }
 
-/// Returns the base `TypeError` class.
+/// Returns the base [`TypeError`](https://www.php.net/manual/en/class.typeerror.php) class.
 pub fn type_error() -> &'static ClassEntry {
     unsafe { zend_ce_type_error.as_ref() }.unwrap()
 }
 
-/// Returns the base `ArgumentCountError` class.
+/// Returns the base [`ArgumentCountError`](https://www.php.net/manual/en/class.argumentcounterror.php) class.
 pub fn argument_count_error() -> &'static ClassEntry {
     unsafe { zend_ce_argument_count_error.as_ref() }.unwrap()
 }
 
-/// Returns the base `ValueError` class.
+/// Returns the base [`ValueError`](https://www.php.net/manual/en/class.valueerror.php) class.
 pub fn value_error() -> &'static ClassEntry {
     unsafe { zend_ce_value_error.as_ref() }.unwrap()
 }
 
-/// Returns the base `ArithmeticError` class.
+/// Returns the base [`ArithmeticError`](https://www.php.net/manual/en/class.arithmeticerror.php) class.
 pub fn arithmetic_error() -> &'static ClassEntry {
     unsafe { zend_ce_arithmetic_error.as_ref() }.unwrap()
 }
 
-/// Returns the base `DivisionByZeroError` class.
+/// Returns the base [`DivisionByZeroError`](https://www.php.net/manual/en/class.divisionbyzeroerror.php) class.
 pub fn division_by_zero_error() -> &'static ClassEntry {
     unsafe { zend_ce_division_by_zero_error.as_ref() }.unwrap()
 }
 
-/// Returns the base `UnhandledMatchError` class.
+/// Returns the base [`UnhandledMatchError`](https://www.php.net/manual/en/class.unhandledmatcherror.php) class.
 pub fn unhandled_match_error() -> &'static ClassEntry {
     unsafe { zend_ce_unhandled_match_error.as_ref() }.unwrap()
 }
+
+/// Returns the [`Traversable`](https://www.php.net/manual/en/class.traversable.php) interface.
+pub fn traversable() -> &'static ClassEntry {
+    unsafe { zend_ce_traversable.as_ref() }.unwrap()
+}
+
+/// Returns the [`IteratorAggregate`](https://www.php.net/manual/en/class.iteratoraggregate.php) interface.
+pub fn aggregate() -> &'static ClassEntry {
+    unsafe { zend_ce_aggregate.as_ref() }.unwrap()
+}
+
+/// Returns the [`Iterator`](https://www.php.net/manual/en/class.iterator.php) interface.
+pub fn iterator() -> &'static ClassEntry {
+    unsafe { zend_ce_iterator.as_ref() }.unwrap()
+}
+
+/// Returns the [`ArrayAccess`](https://www.php.net/manual/en/class.arrayaccess.php) interface.
+pub fn arrayaccess() -> &'static ClassEntry {
+    unsafe { zend_ce_arrayaccess.as_ref() }.unwrap()
+}
+
+/// Returns the [`Serializable`](https://www.php.net/manual/en/class.serializable.php) interface.
+pub fn serializable() -> &'static ClassEntry {
+    unsafe { zend_ce_serializable.as_ref() }.unwrap()
+}
+
+/// Returns the [`Countable`](https://www.php.net/manual/en/class.countable.php) interface.
+pub fn countable() -> &'static ClassEntry {
+    unsafe { zend_ce_countable.as_ref() }.unwrap()
+}
+
+/// Returns the [`Stringable`](https://www.php.net/manual/en/class.stringable.php) interface.
+pub fn stringable() -> &'static ClassEntry {
+    unsafe { zend_ce_stringable.as_ref() }.unwrap()
+}