GH-92898: Make _Py_Cast C++ version compatible with cast operator (gh-92951)

1 files changed, 26 insertions, 2 deletions

diff --git a/Include/pyport.h b/Include/pyport.h
index 614a278..086ed42 100644
--- a/Include/pyport.h
+++ b/Include/pyport.h
@@ -26,8 +26,32 @@
 // _Py_CAST(const PyObject*, expr) fails with a compiler error.
 #ifdef __cplusplus
 #  define _Py_STATIC_CAST(type, expr) static_cast<type>(expr)
-#  define _Py_CAST(type, expr) \
-       const_cast<type>(reinterpret_cast<const type>(expr))
+
+extern "C++" {
+namespace {
+template <typename type, typename expr_type>
+inline type _Py_reinterpret_cast_impl(expr_type *expr) {
+  return reinterpret_cast<type>(expr);
+}
+
+template <typename type, typename expr_type>
+inline type _Py_reinterpret_cast_impl(expr_type const *expr) {
+  return reinterpret_cast<type>(const_cast<expr_type *>(expr));
+}
+
+template <typename type, typename expr_type>
+inline type _Py_reinterpret_cast_impl(expr_type &expr) {
+  return static_cast<type>(expr);
+}
+
+template <typename type, typename expr_type>
+inline type _Py_reinterpret_cast_impl(expr_type const &expr) {
+  return static_cast<type>(const_cast<expr_type &>(expr));
+}
+} // namespace
+}
+#  define _Py_CAST(type, expr) _Py_reinterpret_cast_impl<type>(expr)
+
 #else
 #  define _Py_STATIC_CAST(type, expr) ((type)(expr))
 #  define _Py_CAST(type, expr) ((type)(expr))