Add cmake option(PYBIND11_DISABLE_HANDLE_TYPE_NAME_DEFAULT_IMPLEMENTA…

…TION) and use in some tests.

.github/workflows/ci.yml

@@ -114,6 +114,7 @@ jobs:
       run: >
         cmake -S . -B .
         -DPYBIND11_WERROR=ON
+        -DPYBIND11_DISABLE_HANDLE_TYPE_NAME_DEFAULT_IMPLEMENTATION=ON
         -DPYBIND11_SIMPLE_GIL_MANAGEMENT=ON
         -DPYBIND11_NUMPY_1_ONLY=ON
         -DDOWNLOAD_CATCH=ON

CMakeLists.txt

@@ -107,6 +107,8 @@ endif()
 option(PYBIND11_INSTALL "Install pybind11 header files?" ${PYBIND11_MASTER_PROJECT})
 option(PYBIND11_TEST "Build pybind11 test suite?" ${PYBIND11_MASTER_PROJECT})
 option(PYBIND11_NOPYTHON "Disable search for Python" OFF)
+option(PYBIND11_DISABLE_HANDLE_TYPE_NAME_DEFAULT_IMPLEMENTATION
+       "To enforce that a handle_type_name<> specialization exists" OFF)
 option(PYBIND11_SIMPLE_GIL_MANAGEMENT
        "Use simpler GIL management logic that does not support disassociation" OFF)
 option(PYBIND11_NUMPY_1_ONLY
@@ -115,6 +117,9 @@ set(PYBIND11_INTERNALS_VERSION
     ""
     CACHE STRING "Override the ABI version, may be used to enable the unstable ABI.")
 
+if(PYBIND11_DISABLE_HANDLE_TYPE_NAME_DEFAULT_IMPLEMENTATION)
+  add_compile_definitions(PYBIND11_DISABLE_HANDLE_TYPE_NAME_DEFAULT_IMPLEMENTATION)
+endif()
 if(PYBIND11_SIMPLE_GIL_MANAGEMENT)
   add_compile_definitions(PYBIND11_SIMPLE_GIL_MANAGEMENT)
 endif()