Eliminate pybindit namespace

include/pybind11/detail/common.h

@@ -22,80 +22,7 @@
 // Additional convention: 0xD = dev
 #define PYBIND11_VERSION_HEX 0x030000D1
 
-// Define some generic pybind11 helper macros for warning management.
-//
-// Note that compiler-specific push/pop pairs are baked into the
-// PYBIND11_NAMESPACE_BEGIN/PYBIND11_NAMESPACE_END pair of macros. Therefore manual
-// PYBIND11_WARNING_PUSH/PYBIND11_WARNING_POP are usually only needed in `#include` sections.
-//
-// If you find you need to suppress a warning, please try to make the suppression as local as
-// possible using these macros. Please also be sure to push/pop with the pybind11 macros. Please
-// only use compiler specifics if you need to check specific versions, e.g. Apple Clang vs. vanilla
-// Clang.
-#if defined(_MSC_VER)
-#    define PYBIND11_COMPILER_MSVC
-#    define PYBIND11_PRAGMA(...) __pragma(__VA_ARGS__)
-#    define PYBIND11_WARNING_PUSH PYBIND11_PRAGMA(warning(push))
-#    define PYBIND11_WARNING_POP PYBIND11_PRAGMA(warning(pop))
-#elif defined(__INTEL_COMPILER)
-#    define PYBIND11_COMPILER_INTEL
-#    define PYBIND11_PRAGMA(...) _Pragma(#__VA_ARGS__)
-#    define PYBIND11_WARNING_PUSH PYBIND11_PRAGMA(warning push)
-#    define PYBIND11_WARNING_POP PYBIND11_PRAGMA(warning pop)
-#elif defined(__clang__)
-#    define PYBIND11_COMPILER_CLANG
-#    define PYBIND11_PRAGMA(...) _Pragma(#__VA_ARGS__)
-#    define PYBIND11_WARNING_PUSH PYBIND11_PRAGMA(clang diagnostic push)
-#    define PYBIND11_WARNING_POP PYBIND11_PRAGMA(clang diagnostic pop)
-#elif defined(__GNUC__)
-#    define PYBIND11_COMPILER_GCC
-#    define PYBIND11_PRAGMA(...) _Pragma(#__VA_ARGS__)
-#    define PYBIND11_WARNING_PUSH PYBIND11_PRAGMA(GCC diagnostic push)
-#    define PYBIND11_WARNING_POP PYBIND11_PRAGMA(GCC diagnostic pop)
-#endif
-
-#ifdef PYBIND11_COMPILER_MSVC
-#    define PYBIND11_WARNING_DISABLE_MSVC(name) PYBIND11_PRAGMA(warning(disable : name))
-#else
-#    define PYBIND11_WARNING_DISABLE_MSVC(name)
-#endif
-
-#ifdef PYBIND11_COMPILER_CLANG
-#    define PYBIND11_WARNING_DISABLE_CLANG(name) PYBIND11_PRAGMA(clang diagnostic ignored name)
-#else
-#    define PYBIND11_WARNING_DISABLE_CLANG(name)
-#endif
-
-#ifdef PYBIND11_COMPILER_GCC
-#    define PYBIND11_WARNING_DISABLE_GCC(name) PYBIND11_PRAGMA(GCC diagnostic ignored name)
-#else
-#    define PYBIND11_WARNING_DISABLE_GCC(name)
-#endif
-
-#ifdef PYBIND11_COMPILER_INTEL
-#    define PYBIND11_WARNING_DISABLE_INTEL(name) PYBIND11_PRAGMA(warning disable name)
-#else
-#    define PYBIND11_WARNING_DISABLE_INTEL(name)
-#endif
-
-#define PYBIND11_NAMESPACE_BEGIN(name)                                                            \
-    namespace name {                                                                              \
-    PYBIND11_WARNING_PUSH
-
-#define PYBIND11_NAMESPACE_END(name)                                                              \
-    PYBIND11_WARNING_POP                                                                          \
-    }
-
-// Robust support for some features and loading modules compiled against different pybind versions
-// requires forcing hidden visibility on pybind code, so we enforce this by setting the attribute
-// on the main `pybind11` namespace.
-#if !defined(PYBIND11_NAMESPACE)
-#    ifdef __GNUG__
-#        define PYBIND11_NAMESPACE pybind11 __attribute__((visibility("hidden")))
-#    else
-#        define PYBIND11_NAMESPACE pybind11
-#    endif
-#endif
+#include "pybind11_namespace_macros.h"
 
 #if !(defined(_MSC_VER) && __cplusplus == 199711L)
 #    if __cplusplus >= 201402L

include/pybind11/detail/pybind11_namespace_macros.h

@@ -0,0 +1,82 @@
+// Copyright (c) 2016-2025 The Pybind Development Team.
+// All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#pragma once
+
+// PLEASE DO NOT ADD ANY INCLUDES HERE
+
+// Define some generic pybind11 helper macros for warning management.
+//
+// Note that compiler-specific push/pop pairs are baked into the
+// PYBIND11_NAMESPACE_BEGIN/PYBIND11_NAMESPACE_END pair of macros. Therefore manual
+// PYBIND11_WARNING_PUSH/PYBIND11_WARNING_POP are usually only needed in `#include` sections.
+//
+// If you find you need to suppress a warning, please try to make the suppression as local as
+// possible using these macros. Please also be sure to push/pop with the pybind11 macros. Please
+// only use compiler specifics if you need to check specific versions, e.g. Apple Clang vs. vanilla
+// Clang.
+#if defined(_MSC_VER)
+#    define PYBIND11_COMPILER_MSVC
+#    define PYBIND11_PRAGMA(...) __pragma(__VA_ARGS__)
+#    define PYBIND11_WARNING_PUSH PYBIND11_PRAGMA(warning(push))
+#    define PYBIND11_WARNING_POP PYBIND11_PRAGMA(warning(pop))
+#elif defined(__INTEL_COMPILER)
+#    define PYBIND11_COMPILER_INTEL
+#    define PYBIND11_PRAGMA(...) _Pragma(#__VA_ARGS__)
+#    define PYBIND11_WARNING_PUSH PYBIND11_PRAGMA(warning push)
+#    define PYBIND11_WARNING_POP PYBIND11_PRAGMA(warning pop)
+#elif defined(__clang__)
+#    define PYBIND11_COMPILER_CLANG
+#    define PYBIND11_PRAGMA(...) _Pragma(#__VA_ARGS__)
+#    define PYBIND11_WARNING_PUSH PYBIND11_PRAGMA(clang diagnostic push)
+#    define PYBIND11_WARNING_POP PYBIND11_PRAGMA(clang diagnostic pop)
+#elif defined(__GNUC__)
+#    define PYBIND11_COMPILER_GCC
+#    define PYBIND11_PRAGMA(...) _Pragma(#__VA_ARGS__)
+#    define PYBIND11_WARNING_PUSH PYBIND11_PRAGMA(GCC diagnostic push)
+#    define PYBIND11_WARNING_POP PYBIND11_PRAGMA(GCC diagnostic pop)
+#endif
+
+#ifdef PYBIND11_COMPILER_MSVC
+#    define PYBIND11_WARNING_DISABLE_MSVC(name) PYBIND11_PRAGMA(warning(disable : name))
+#else
+#    define PYBIND11_WARNING_DISABLE_MSVC(name)
+#endif
+
+#ifdef PYBIND11_COMPILER_CLANG
+#    define PYBIND11_WARNING_DISABLE_CLANG(name) PYBIND11_PRAGMA(clang diagnostic ignored name)
+#else
+#    define PYBIND11_WARNING_DISABLE_CLANG(name)
+#endif
+
+#ifdef PYBIND11_COMPILER_GCC
+#    define PYBIND11_WARNING_DISABLE_GCC(name) PYBIND11_PRAGMA(GCC diagnostic ignored name)
+#else
+#    define PYBIND11_WARNING_DISABLE_GCC(name)
+#endif
+
+#ifdef PYBIND11_COMPILER_INTEL
+#    define PYBIND11_WARNING_DISABLE_INTEL(name) PYBIND11_PRAGMA(warning disable name)
+#else
+#    define PYBIND11_WARNING_DISABLE_INTEL(name)
+#endif
+
+#define PYBIND11_NAMESPACE_BEGIN(name)                                                            \
+    namespace name {                                                                              \
+    PYBIND11_WARNING_PUSH
+
+#define PYBIND11_NAMESPACE_END(name)                                                              \
+    PYBIND11_WARNING_POP                                                                          \
+    }
+
+// Robust support for some features and loading modules compiled against different pybind versions
+// requires forcing hidden visibility on pybind code, so we enforce this by setting the attribute
+// on the main `pybind11` namespace.
+#if !defined(PYBIND11_NAMESPACE)
+#    ifdef __GNUG__
+#        define PYBIND11_NAMESPACE pybind11 __attribute__((visibility("hidden")))
+#    else
+#        define PYBIND11_NAMESPACE pybind11
+#    endif
+#endif

include/pybind11/detail/struct_smart_holder.h

@@ -48,6 +48,8 @@ High-level aspects:
 
 #pragma once
 
+#include "pybind11_namespace_macros.h"
+
 #include <functional>
 #include <memory>
 #include <stdexcept>
@@ -56,11 +58,8 @@ High-level aspects:
 #include <typeinfo>
 #include <utility>
 
-// pybindit = Python Bindings Innovation Track.
-// Currently not in pybind11 namespace to signal that this POC does not depend
-// on any existing pybind11 functionality.
-namespace pybindit {
-namespace memory {
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(memory)
 
 // Default fallback.
 static constexpr bool type_has_shared_from_this(...) { return false; }
@@ -355,5 +354,5 @@ struct smart_holder {
     }
 };
 
-} // namespace memory
-} // namespace pybindit
+PYBIND11_NAMESPACE_END(memory)
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

include/pybind11/detail/type_caster_base.h

@@ -543,7 +543,7 @@ struct value_and_holder_helper {
 
     // have_holder() must be true or this function will fail.
     void throw_if_instance_is_currently_owned_by_shared_ptr() const {
-        auto *vptr_gd_ptr = std::get_deleter<pybindit::memory::guarded_delete>(holder().vptr);
+        auto *vptr_gd_ptr = std::get_deleter<memory::guarded_delete>(holder().vptr);
         if (vptr_gd_ptr != nullptr && !vptr_gd_ptr->released_ptr.expired()) {
             throw value_error("Python instance is currently owned by a std::shared_ptr.");
         }
@@ -770,7 +770,7 @@ struct load_helper : value_and_holder_helper {
         }
         auto *type_raw_ptr = static_cast<T *>(void_raw_ptr);
         if (python_instance_is_alias) {
-            auto *vptr_gd_ptr = std::get_deleter<pybindit::memory::guarded_delete>(hld.vptr);
+            auto *vptr_gd_ptr = std::get_deleter<memory::guarded_delete>(hld.vptr);
             if (vptr_gd_ptr != nullptr) {
                 std::shared_ptr<void> released_ptr = vptr_gd_ptr->released_ptr.lock();
                 if (released_ptr) {
@@ -790,8 +790,7 @@ struct load_helper : value_and_holder_helper {
                                   "loaded_v_h.inst == sptsls_ptr->self");
                 }
             }
-            if (sptsls_ptr != nullptr
-                || !pybindit::memory::type_has_shared_from_this(type_raw_ptr)) {
+            if (sptsls_ptr != nullptr || !memory::type_has_shared_from_this(type_raw_ptr)) {
                 return std::shared_ptr<T>(
                     type_raw_ptr, shared_ptr_trampoline_self_life_support(loaded_v_h.inst));
             }

include/pybind11/detail/using_smart_holder.h

@@ -11,7 +11,7 @@
 
 PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
 
-using pybindit::memory::smart_holder;
+using pybind11::memory::smart_holder;
 
 PYBIND11_NAMESPACE_BEGIN(detail)
 

tests/extra_python_package/test_files.py

@@ -69,6 +69,7 @@
     "include/pybind11/detail/init.h",
     "include/pybind11/detail/internals.h",
     "include/pybind11/detail/native_enum_data.h",
+    "include/pybind11/detail/pybind11_namespace_macros.h",
     "include/pybind11/detail/struct_smart_holder.h",
     "include/pybind11/detail/type_caster_base.h",
     "include/pybind11/detail/typeid.h",

tests/pure_cpp/smart_holder_poc.h

@@ -6,12 +6,12 @@
 
 #include "pybind11/detail/struct_smart_holder.h"
 
-namespace pybindit {
-namespace memory {
-namespace smart_holder_poc { // Proof-of-Concept implementations.
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(memory)
+PYBIND11_NAMESPACE_BEGIN(smart_holder_poc) // Proof-of-Concept implementations.
 
 struct PrivateESFT : private std::enable_shared_from_this<PrivateESFT> {};
-static_assert(!pybindit::memory::type_has_shared_from_this(static_cast<PrivateESFT *>(nullptr)),
+static_assert(!type_has_shared_from_this(static_cast<PrivateESFT *>(nullptr)),
               "should detect inaccessible base");
 
 template <typename T>
@@ -50,6 +50,6 @@ std::unique_ptr<T, D> as_unique_ptr(smart_holder &hld) {
     return std::unique_ptr<T, D>(raw_ptr);
 }
 
-} // namespace smart_holder_poc
-} // namespace memory
-} // namespace pybindit
+PYBIND11_NAMESPACE_END(smart_holder_poc)
+PYBIND11_NAMESPACE_END(memory)
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

tests/pure_cpp/smart_holder_poc_test.cpp

@@ -13,8 +13,8 @@
 #define CATCH_CONFIG_MAIN
 #include "catch.hpp"
 
-using pybindit::memory::smart_holder;
-namespace poc = pybindit::memory::smart_holder_poc;
+using pybind11::memory::smart_holder;
+namespace poc = pybind11::memory::smart_holder_poc;
 
 namespace helpers {