From d0003f5660362dd08ca48545b8b88bf8628abfdc Mon Sep 17 00:00:00 2001
From: "Ralf W. Grosse-Kunstleve" <rwgk@google.com>
Date: Sat, 20 Jul 2024 17:53:37 -0700
Subject: [PATCH] Move `classh` into pybind11/pybind11.h and update
 test_classh_mock.cpp accordingly.

---
 include/pybind11/pybind11.h     | 12 ++++++++++++
 include/pybind11/smart_holder.h | 18 ++----------------
 tests/test_classh_mock.cpp      | 14 ++++++++------
 3 files changed, 22 insertions(+), 22 deletions(-)

diff --git a/include/pybind11/pybind11.h b/include/pybind11/pybind11.h
index 7c26f1d985..b7717f69b5 100644
--- a/include/pybind11/pybind11.h
+++ b/include/pybind11/pybind11.h
@@ -2308,6 +2308,18 @@ class class_ : public detail::generic_type {
     }
 };
 
+#ifdef PYBIND11_HAVE_INTERNALS_WITH_SMART_HOLDER_SUPPORT
+
+// Supports easier switching between py::class_<T> and py::class_<T, py::smart_holder>:
+// users can simply replace the `_` in `class_` with `h` or vice versa.
+template <typename type_, typename... options>
+class classh : public class_<type_, smart_holder, options...> {
+public:
+    using class_<type_, smart_holder, options...>::class_;
+};
+
+#endif
+
 /// Binds an existing constructor taking arguments Args...
 template <typename... Args>
 detail::initimpl::constructor<Args...> init() {
diff --git a/include/pybind11/smart_holder.h b/include/pybind11/smart_holder.h
index 6ca9e7d3d5..5f568a5529 100644
--- a/include/pybind11/smart_holder.h
+++ b/include/pybind11/smart_holder.h
@@ -6,23 +6,9 @@
 
 #include "pybind11.h"
 
+// Legacy macros introduced with smart_holder_type_casters implementation in 2021.
+// Deprecated.
 #define PYBIND11_TYPE_CASTER_BASE_HOLDER(...)
 #define PYBIND11_SMART_HOLDER_TYPE_CASTERS(...)
 #define PYBIND11_SH_AVL(...) // "Smart_Holder if AVaiLable"
 #define PYBIND11_SH_DEF(...) // "Smart_Holder if DEFault"
-
-PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
-
-#ifdef PYBIND11_HAVE_INTERNALS_WITH_SMART_HOLDER_SUPPORT
-
-// Supports easier switching between py::class_<T> and py::class_<T, py::smart_holder>:
-// users can simply replace the `_` in `class_` with `h` or vice versa.
-template <typename type_, typename... options>
-class classh : public class_<type_, smart_holder, options...> {
-public:
-    using class_<type_, smart_holder, options...>::class_;
-};
-
-#endif
-
-PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)
diff --git a/tests/test_classh_mock.cpp b/tests/test_classh_mock.cpp
index 38e765fb01..135320320f 100644
--- a/tests/test_classh_mock.cpp
+++ b/tests/test_classh_mock.cpp
@@ -1,18 +1,20 @@
 #include "pybind11_tests.h"
 
-// The main purpose of this test is to ensure the suggested BOILERPLATE code block below is
-// correct.
+// The main purpose of this test was to ensure that the suggested
+// BOILERPLATE code block (NOW DEPRECATED!) block below is correct.
 
 // Copy this block of code into your project.
 // Replace FOOEXT with the name of your project.
-// BOILERPLATE BEGIN
+// BOILERPLATE BEGIN DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED
 #ifdef FOOEXT_USING_PYBIND11_SMART_HOLDER
 #    include <pybind11/smart_holder.h>
 #else
 #    include <pybind11/pybind11.h>
 PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+#    ifndef PYBIND11_HAVE_INTERNALS_WITH_SMART_HOLDER_SUPPORT
 template <typename type_, typename... options>
 using classh = class_<type_, options...>;
+#    endif
 PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)
 #    ifndef PYBIND11_SH_AVL
 #        define PYBIND11_SH_AVL(...) std::shared_ptr<__VA_ARGS__> // "Smart_Holder if AVaiLable"
@@ -27,7 +29,7 @@ PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)
 #        define PYBIND11_TYPE_CASTER_BASE_HOLDER(...)
 #    endif
 #endif
-// BOILERPLATE END
+// BOILERPLATE END DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED
 
 namespace {
 struct FooUc {};
@@ -37,8 +39,8 @@ struct FooSc {};
 struct FooSp {};
 } // namespace
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(FooUp)
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(FooSp)
+PYBIND11_SMART_HOLDER_TYPE_CASTERS(FooUp) // DEPRECATED
+PYBIND11_SMART_HOLDER_TYPE_CASTERS(FooSp) // DEPRECATED
 
 PYBIND11_TYPE_CASTER_BASE_HOLDER(FooSa, std::shared_ptr<FooSa>)