[smart_holder] git merge master

docs/changelog.rst

@@ -15,6 +15,20 @@ IN DEVELOPMENT
 
 Changes will be summarized here periodically.
 
+Version 2.13.1 (June 26, 2024)
+------------------------------
+
+New Features:
+
+* Add support for ``Typing.Callable[..., T]``.
+  `#5202 <https://github.com/pybind/pybind11/pull/5202>`_
+
+Bug fixes:
+
+* Avoid aligned allocation in free-threaded build in order to support macOS
+  versions before 10.14.
+  `#5200 <https://github.com/pybind/pybind11/pull/5200>`_
+
 Version 2.13.0 (June 25, 2024)
 ------------------------------
 

include/pybind11/detail/internals.h

@@ -149,18 +149,14 @@ struct override_hash {
 
 using instance_map = std::unordered_multimap<const void *, instance *>;
 
-// ignore: structure was padded due to alignment specifier
-PYBIND11_WARNING_PUSH
-PYBIND11_WARNING_DISABLE_MSVC(4324)
-
 // Instance map shards are used to reduce mutex contention in free-threaded Python.
-struct alignas(64) instance_map_shard {
+struct instance_map_shard {
     std::mutex mutex;
     instance_map registered_instances;
+    // alignas(64) would be better, but causes compile errors in macOS before 10.14 (see #5200)
+    char padding[64 - (sizeof(std::mutex) + sizeof(instance_map)) % 64];
 };
 
-PYBIND11_WARNING_POP
-
 /// Internal data structure used to track registered instances and types.
 /// Whenever binary incompatible changes are made to this structure,
 /// `PYBIND11_INTERNALS_VERSION` must be incremented.

include/pybind11/typing.h

@@ -177,6 +177,14 @@ struct handle_type_name<typing::Callable<Return(Args...)>> {
           + const_name("], ") + make_caster<retval_type>::name + const_name("]");
 };
 
+template <typename Return>
+struct handle_type_name<typing::Callable<Return(ellipsis)>> {
+    // PEP 484 specifies this syntax for defining only return types of callables
+    using retval_type = conditional_t<std::is_same<Return, void>::value, void_type, Return>;
+    static constexpr auto name
+        = const_name("Callable[..., ") + make_caster<retval_type>::name + const_name("]");
+};
+
 template <typename T>
 struct handle_type_name<typing::Type<T>> {
     static constexpr auto name = const_name("type[") + make_caster<T>::name + const_name("]");

tests/test_pytypes.cpp

@@ -865,6 +865,7 @@ TEST_SUBMODULE(pytypes, m) {
     m.def("annotate_fn",
           [](const py::typing::Callable<int(py::typing::List<py::str>, py::str)> &) {});
 
+    m.def("annotate_fn_only_return", [](const py::typing::Callable<int(py::ellipsis)> &) {});
     m.def("annotate_type", [](const py::typing::Type<int> &t) -> py::type { return t; });
 
     m.def("annotate_union",

tests/test_pytypes.py

@@ -959,6 +959,13 @@ def test_fn_annotations(doc):
     )
 
 
+def test_fn_return_only(doc):
+    assert (
+        doc(m.annotate_fn_only_return)
+        == "annotate_fn_only_return(arg0: Callable[..., int]) -> None"
+    )
+
+
 def test_type_annotation(doc):
     assert doc(m.annotate_type) == "annotate_type(arg0: type[int]) -> type"