diff --git a/.cmake-format.yaml b/.cmake-format.yaml
index fc69b40a0..a2a69f3f8 100644
--- a/.cmake-format.yaml
+++ b/.cmake-format.yaml
@@ -67,3 +67,7 @@ format:
   # If true, the parsers may infer whether or not an argument
   # list is sortable (without annotation).
   autosort: false
+
+# Causes a few issues - can be solved later, possibly.
+markup:
+  enable_markup: false
diff --git a/CMakeLists.txt b/CMakeLists.txt
index d5a39b4d7..31e253f9d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -10,37 +10,30 @@ cmake_minimum_required(VERSION 3.7)
 # VERSION 3.7...3.18, but some versions of MCVS have a patched CMake 3.11
 # that do not work properly with this syntax, so using the following workaround:
 if(${CMAKE_VERSION} VERSION_LESS 3.18)
-    cmake_policy(VERSION ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION})
+  cmake_policy(VERSION ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION})
 else()
-    cmake_policy(VERSION 3.18)
+  cmake_policy(VERSION 3.18)
 endif()
 
 # Extract project version from source
-file(
-  STRINGS
-    "${CMAKE_CURRENT_SOURCE_DIR}/include/pybind11/detail/common.h"
-  pybind11_version_defines
-  REGEX
-    "#define PYBIND11_VERSION_(MAJOR|MINOR|PATCH) ")
+file(STRINGS "${CMAKE_CURRENT_SOURCE_DIR}/include/pybind11/detail/common.h"
+     pybind11_version_defines REGEX "#define PYBIND11_VERSION_(MAJOR|MINOR|PATCH) ")
 
 foreach(ver ${pybind11_version_defines})
-    if (ver MATCHES [[#define PYBIND11_VERSION_(MAJOR|MINOR|PATCH) +([^ ]+)$]])
-        set(PYBIND11_VERSION_${CMAKE_MATCH_1} "${CMAKE_MATCH_2}")
-    endif()
+  if(ver MATCHES [[#define PYBIND11_VERSION_(MAJOR|MINOR|PATCH) +([^ ]+)$]])
+    set(PYBIND11_VERSION_${CMAKE_MATCH_1} "${CMAKE_MATCH_2}")
+  endif()
 endforeach()
 
 if(PYBIND11_VERSION_PATCH MATCHES [[([a-zA-Z]+)]])
-    set(PYBIND11_VERSION_TYPE "${CMAKE_MATCH_1}")
+  set(PYBIND11_VERSION_TYPE "${CMAKE_MATCH_1}")
 endif()
 string(REGEX MATCH "[0-9]+" PYBIND11_VERSION_PATCH "${PYBIND11_VERSION_PATCH}")
 
 project(
-    pybind11
-  LANGUAGES
-    CXX
-  VERSION
-    "${PYBIND11_VERSION_MAJOR}.${PYBIND11_VERSION_MINOR}.${PYBIND11_VERSION_PATCH}"
-)
+  pybind11
+  LANGUAGES CXX
+  VERSION "${PYBIND11_VERSION_MAJOR}.${PYBIND11_VERSION_MINOR}.${PYBIND11_VERSION_PATCH}")
 
 # Standard includes
 include(GNUInstallDirs)
@@ -51,26 +44,25 @@ message(STATUS "pybind11 v${pybind11_VERSION} ${PYBIND11_VERSION_TYPE}")
 
 # Check if pybind11 is being used directly or via add_subdirectory
 if(CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)
-    set(PYBIND11_MASTER_PROJECT ON)
-    message(STATUS "CMake ${CMAKE_VERSION}")
+  set(PYBIND11_MASTER_PROJECT ON)
+  message(STATUS "CMake ${CMAKE_VERSION}")
 
-    if(CMAKE_CXX_STANDARD)
-        set(CMAKE_CXX_EXTENSIONS OFF)
-        set(CMAKE_CXX_STANDARD_REQUIRED ON)
-    endif()
+  if(CMAKE_CXX_STANDARD)
+    set(CMAKE_CXX_EXTENSIONS OFF)
+    set(CMAKE_CXX_STANDARD_REQUIRED ON)
+  endif()
 else()
-    set(PYBIND11_MASTER_PROJECT OFF)
-    set(pybind11_system SYSTEM)
+  set(PYBIND11_MASTER_PROJECT OFF)
+  set(pybind11_system SYSTEM)
 endif()
 
 option(PYBIND11_INSTALL "Install pybind11 header files?" ${PYBIND11_MASTER_PROJECT})
 option(PYBIND11_TEST "Build pybind11 test suite?" ${PYBIND11_MASTER_PROJECT})
 option(PYBIND11_CLASSIC_LTO "Use the classic LTO flag algorithm, even on CMake 3.9+" OFF)
 cmake_dependent_option(
-    USE_PYTHON_INCLUDE_DIR
-    "Install pybind11 headers in Python include directory instead of default installation prefix" OFF
-    "PYBIND11_INSTALL" OFF
-)
+  USE_PYTHON_INCLUDE_DIR
+  "Install pybind11 headers in Python include directory instead of default installation prefix"
+  OFF "PYBIND11_INSTALL" OFF)
 
 # NB: when adding a header don't forget to also add it to setup.py
 set(PYBIND11_HEADERS
@@ -96,16 +88,14 @@ set(PYBIND11_HEADERS
     include/pybind11/pybind11.h
     include/pybind11/pytypes.h
     include/pybind11/stl.h
-    include/pybind11/stl_bind.h
-)
+    include/pybind11/stl_bind.h)
 
 # TODO: compare with grep and warn if missmatched
 
 # cmake 3.12 added list(TRANSFORM <list> PREPEND
 # But we can't use it yet
-string(REPLACE "include/" "${CMAKE_CURRENT_SOURCE_DIR}/include/"
-       PYBIND11_HEADERS "${PYBIND11_HEADERS}")
-
+string(REPLACE "include/" "${CMAKE_CURRENT_SOURCE_DIR}/include/" PYBIND11_HEADERS
+               "${PYBIND11_HEADERS}")
 
 # Classic mode
 
@@ -113,23 +103,37 @@ list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/tools")
 include(pybind11Tools)
 
 # Cache variables so pybind11_add_module can be used in parent projects
-set(PYBIND11_INCLUDE_DIR "${CMAKE_CURRENT_LIST_DIR}/include" CACHE INTERNAL "")
-set(PYTHON_INCLUDE_DIRS ${PYTHON_INCLUDE_DIRS} CACHE INTERNAL "")
-set(PYTHON_LIBRARIES ${PYTHON_LIBRARIES} CACHE INTERNAL "")
-set(PYTHON_MODULE_PREFIX ${PYTHON_MODULE_PREFIX} CACHE INTERNAL "")
-set(PYTHON_MODULE_EXTENSION ${PYTHON_MODULE_EXTENSION} CACHE INTERNAL "")
-set(PYTHON_VERSION_MAJOR ${PYTHON_VERSION_MAJOR} CACHE INTERNAL "")
-set(PYTHON_VERSION_MINOR ${PYTHON_VERSION_MINOR} CACHE INTERNAL "")
-set(PYTHON_IS_DEBUG "${PYTHON_IS_DEBUG}" CACHE INTERNAL "")
-
+set(PYBIND11_INCLUDE_DIR
+    "${CMAKE_CURRENT_LIST_DIR}/include"
+    CACHE INTERNAL "")
+set(PYTHON_INCLUDE_DIRS
+    ${PYTHON_INCLUDE_DIRS}
+    CACHE INTERNAL "")
+set(PYTHON_LIBRARIES
+    ${PYTHON_LIBRARIES}
+    CACHE INTERNAL "")
+set(PYTHON_MODULE_PREFIX
+    ${PYTHON_MODULE_PREFIX}
+    CACHE INTERNAL "")
+set(PYTHON_MODULE_EXTENSION
+    ${PYTHON_MODULE_EXTENSION}
+    CACHE INTERNAL "")
+set(PYTHON_VERSION_MAJOR
+    ${PYTHON_VERSION_MAJOR}
+    CACHE INTERNAL "")
+set(PYTHON_VERSION_MINOR
+    ${PYTHON_VERSION_MINOR}
+    CACHE INTERNAL "")
+set(PYTHON_IS_DEBUG
+    "${PYTHON_IS_DEBUG}"
+    CACHE INTERNAL "")
 
 if(PYBIND11_TEST OR (BUILD_TESTING AND PYBIND11_MASTER_PROJECT))
-    add_subdirectory(tests)
+  add_subdirectory(tests)
 endif()
 
-
 if(USE_PYTHON_INCLUDE_DIR)
-    file(RELATIVE_PATH CMAKE_INSTALL_INCLUDEDIR ${CMAKE_INSTALL_PREFIX} ${PYTHON_INCLUDE_DIRS})
+  file(RELATIVE_PATH CMAKE_INSTALL_INCLUDEDIR ${CMAKE_INSTALL_PREFIX} ${PYTHON_INCLUDE_DIRS})
 endif()
 
 # Note: when creating targets, you cannot use if statements at configure time -
@@ -138,26 +142,22 @@ endif()
 
 # Build an interface library target:
 add_library(pybind11 INTERFACE)
-add_library(pybind11::pybind11 ALIAS pybind11)  # to match exported target
+add_library(pybind11::pybind11 ALIAS pybind11) # to match exported target
 
-target_include_directories(pybind11 ${pybind11_system} INTERFACE $<BUILD_INTERFACE:${PYBIND11_INCLUDE_DIR}>
-                                                                 $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
+target_include_directories(
+  pybind11 ${pybind11_system} INTERFACE $<BUILD_INTERFACE:${PYBIND11_INCLUDE_DIR}>
+                                        $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
 # Only add Python for build - must be added during the import for config since it has to be re-discovered.
 target_include_directories(pybind11 SYSTEM INTERFACE $<BUILD_INTERFACE:${PYTHON_INCLUDE_DIRS}>)
 
 if(CMAKE_VERSION VERSION_LESS 3.13)
-    target_compile_features(
-        pybind11
-      INTERFACE
-        cxx_inheriting_constructors
-        cxx_user_literals
-        cxx_right_angle_brackets
-      )
+  target_compile_features(pybind11 INTERFACE cxx_inheriting_constructors cxx_user_literals
+                                             cxx_right_angle_brackets)
 else()
-    # This was added in CMake 3.8, but we are keeping a consistent breaking
-    # point for the config file at 3.13. A config generated by CMake 3.13+
-    # can only be read in 3.13+ due to the SHELL usage later, so this is safe to do.
-    target_compile_features(pybind11 INTERFACE cxx_std_11)
+  # This was added in CMake 3.8, but we are keeping a consistent breaking
+  # point for the config file at 3.13. A config generated by CMake 3.13+
+  # can only be read in 3.13+ due to the SHELL usage later, so this is safe to do.
+  target_compile_features(pybind11 INTERFACE cxx_std_11)
 endif()
 
 add_library(module INTERFACE)
@@ -167,23 +167,26 @@ target_link_libraries(module INTERFACE pybind11::pybind11)
 
 # See https://github.com/Kitware/CMake/blob/master/Modules/CMakePlatformId.h.in for platform IDs
 # Note: CMake 3.15 allows $<PLATFORM_ID:Windows,Cygwin>
-target_link_libraries(module INTERFACE "$<$<OR:$<PLATFORM_ID:Windows>,$<PLATFORM_ID:Cygwin>>:$<BUILD_INTERFACE:${PYTHON_LIBRARIES}>>")
+target_link_libraries(
+  module
+  INTERFACE
+    "$<$<OR:$<PLATFORM_ID:Windows>,$<PLATFORM_ID:Cygwin>>:$<BUILD_INTERFACE:${PYTHON_LIBRARIES}>>")
 
 if(CMAKE_VERSION VERSION_LESS 3.13)
-    target_link_libraries(module INTERFACE "$<$<PLATFORM_ID:Darwin>:-undefined dynamic_lookup>")
+  target_link_libraries(module INTERFACE "$<$<PLATFORM_ID:Darwin>:-undefined dynamic_lookup>")
 else()
-    # SHELL (3.12+) forces this to remain together, and link_options was added in 3.13+
-    # This is safer, because you are ensured the deduplication pass in CMake will not consider
-    # these separate and remove one but not the other.
-    target_link_options(module INTERFACE "$<$<PLATFORM_ID:Darwin>:SHELL:-undefined dynamic_lookup>")
+  # SHELL (3.12+) forces this to remain together, and link_options was added in 3.13+
+  # This is safer, because you are ensured the deduplication pass in CMake will not consider
+  # these separate and remove one but not the other.
+  target_link_options(module INTERFACE "$<$<PLATFORM_ID:Darwin>:SHELL:-undefined dynamic_lookup>")
 endif()
 
-
 # Workaround for Python 2.7 and C++17 (C++14 as a warning) incompatibility
 # This adds the flags -Wno-register and -Wno-deprecated-register if the compiler
 # is Clang 3.9+ or AppleClang and the compile language is CXX, or /wd5033 for MSVC (all languages,
 # since MSVC didn't recognize COMPILE_LANGUAGE until CMake 3.11+).
-set(clang_4plus "$<AND:$<CXX_COMPILER_ID:Clang>,$<NOT:$<VERSION_LESS:$<CXX_COMPILER_VERSION>,3.9>>>")
+set(clang_4plus
+    "$<AND:$<CXX_COMPILER_ID:Clang>,$<NOT:$<VERSION_LESS:$<CXX_COMPILER_VERSION>,3.9>>>")
 set(no_register "$<OR:${clang_4plus},$<CXX_COMPILER_ID:AppleClang>>")
 set(cxx_no_register "$<AND:$<COMPILE_LANGUAGE:CXX>,${no_register}>")
 set(msvc "$<CXX_COMPILER_ID:MSVC>")
@@ -196,58 +199,50 @@ add_library(pybind11::embed ALIAS embed)
 target_link_libraries(embed INTERFACE pybind11::pybind11 $<BUILD_INTERFACE:${PYTHON_LIBRARIES}>)
 
 if(PYBIND11_INSTALL)
-    install(DIRECTORY ${PYBIND11_INCLUDE_DIR}/pybind11 DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
-    # GNUInstallDirs "DATADIR" wrong here; CMake search path wants "share".
-    set(PYBIND11_CMAKECONFIG_INSTALL_DIR "share/cmake/${PROJECT_NAME}" CACHE STRING "install path for pybind11Config.cmake")
+  install(DIRECTORY ${PYBIND11_INCLUDE_DIR}/pybind11 DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+  # GNUInstallDirs "DATADIR" wrong here; CMake search path wants "share".
+  set(PYBIND11_CMAKECONFIG_INSTALL_DIR
+      "share/cmake/${PROJECT_NAME}"
+      CACHE STRING "install path for pybind11Config.cmake")
 
-    configure_package_config_file(tools/${PROJECT_NAME}Config.cmake.in
-                                  "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Config.cmake"
-                                  INSTALL_DESTINATION ${PYBIND11_CMAKECONFIG_INSTALL_DIR})
+  configure_package_config_file(
+    tools/${PROJECT_NAME}Config.cmake.in "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Config.cmake"
+    INSTALL_DESTINATION ${PYBIND11_CMAKECONFIG_INSTALL_DIR})
 
-    if(CMAKE_VERSION VERSION_LESS 3.14)
-        # Remove CMAKE_SIZEOF_VOID_P from ConfigVersion.cmake since the library does
-        # not depend on architecture specific settings or libraries.
-        set(_PYBIND11_CMAKE_SIZEOF_VOID_P ${CMAKE_SIZEOF_VOID_P})
-        unset(CMAKE_SIZEOF_VOID_P)
+  if(CMAKE_VERSION VERSION_LESS 3.14)
+    # Remove CMAKE_SIZEOF_VOID_P from ConfigVersion.cmake since the library does
+    # not depend on architecture specific settings or libraries.
+    set(_PYBIND11_CMAKE_SIZEOF_VOID_P ${CMAKE_SIZEOF_VOID_P})
+    unset(CMAKE_SIZEOF_VOID_P)
 
-        write_basic_package_version_file(
-            ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake
-          VERSION
-            ${PROJECT_VERSION}
-          COMPATIBILITY
-            AnyNewerVersion
-        )
+    write_basic_package_version_file(
+      ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake
+      VERSION ${PROJECT_VERSION}
+      COMPATIBILITY AnyNewerVersion)
 
-        set(CMAKE_SIZEOF_VOID_P ${_PYBIND11_CMAKE_SIZEOF_VOID_P})
-    else()
-        # CMake 3.14+ natively supports header-only libraries
-        write_basic_package_version_file(
-            ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake
-          VERSION
-            ${PROJECT_VERSION}
-          COMPATIBILITY
-            AnyNewerVersion
-          ARCH_INDEPENDENT
-        )
-    endif()
+    set(CMAKE_SIZEOF_VOID_P ${_PYBIND11_CMAKE_SIZEOF_VOID_P})
+  else()
+    # CMake 3.14+ natively supports header-only libraries
+    write_basic_package_version_file(
+      ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake
+      VERSION ${PROJECT_VERSION}
+      COMPATIBILITY AnyNewerVersion ARCH_INDEPENDENT)
+  endif()
 
-    install(
-      FILES
-        ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Config.cmake
-        ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake
-        tools/FindPythonLibsNew.cmake
-        tools/pybind11Tools.cmake
-      DESTINATION
-        ${PYBIND11_CMAKECONFIG_INSTALL_DIR})
+  install(
+    FILES ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Config.cmake
+          ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake
+          tools/FindPythonLibsNew.cmake tools/pybind11Tools.cmake
+    DESTINATION ${PYBIND11_CMAKECONFIG_INSTALL_DIR})
 
-    if(NOT PYBIND11_EXPORT_NAME)
-        set(PYBIND11_EXPORT_NAME "${PROJECT_NAME}Targets")
-    endif()
+  if(NOT PYBIND11_EXPORT_NAME)
+    set(PYBIND11_EXPORT_NAME "${PROJECT_NAME}Targets")
+  endif()
 
-    install(TARGETS pybind11 module embed
-            EXPORT "${PYBIND11_EXPORT_NAME}")
+  install(TARGETS pybind11 module embed EXPORT "${PYBIND11_EXPORT_NAME}")
 
-    install(EXPORT "${PYBIND11_EXPORT_NAME}"
-            NAMESPACE "pybind11::"
-            DESTINATION ${PYBIND11_CMAKECONFIG_INSTALL_DIR})
+  install(
+    EXPORT "${PYBIND11_EXPORT_NAME}"
+    NAMESPACE "pybind11::"
+    DESTINATION ${PYBIND11_CMAKECONFIG_INSTALL_DIR})
 endif()
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index cab273bc1..5dea63acd 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -10,84 +10,91 @@ cmake_minimum_required(VERSION 3.7)
 # VERSION 3.7...3.18, but some versions of VS have a patched CMake 3.11
 # that do not work properly with this syntax, so using the following workaround:
 if(${CMAKE_VERSION} VERSION_LESS 3.18)
-    cmake_policy(VERSION ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION})
+  cmake_policy(VERSION ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION})
 else()
-    cmake_policy(VERSION 3.18)
+  cmake_policy(VERSION 3.18)
 endif()
 
 # There's no harm in including a project in a project
 project(pybind11_tests CXX)
 
-option(PYBIND11_WERROR  "Report all warnings as errors"  OFF)
+option(PYBIND11_WERROR "Report all warnings as errors" OFF)
 option(DOWNLOAD_EIGEN "Download EIGEN (requires CMake 3.11+)" OFF)
-set(PYBIND11_TEST_OVERRIDE "" CACHE STRING "Tests from ;-separated list of *.cpp files will be built instead of all tests")
+set(PYBIND11_TEST_OVERRIDE
+    ""
+    CACHE STRING "Tests from ;-separated list of *.cpp files will be built instead of all tests")
 
 if(CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)
-    # We're being loaded directly, i.e. not via add_subdirectory, so make this
-    # work as its own project and load the pybind11Config to get the tools we need
-    find_package(pybind11 REQUIRED CONFIG)
+  # We're being loaded directly, i.e. not via add_subdirectory, so make this
+  # work as its own project and load the pybind11Config to get the tools we need
+  find_package(pybind11 REQUIRED CONFIG)
 endif()
 
 if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
   message(STATUS "Setting tests build type to MinSizeRel as none was specified")
-  set(CMAKE_BUILD_TYPE MinSizeRel CACHE STRING "Choose the type of build." FORCE)
-  set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS "Debug" "Release"
-    "MinSizeRel" "RelWithDebInfo")
+  set(CMAKE_BUILD_TYPE
+      MinSizeRel
+      CACHE STRING "Choose the type of build." FORCE)
+  set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS "Debug" "Release" "MinSizeRel"
+                                               "RelWithDebInfo")
 endif()
 
 # Full set of test files (you can override these; see below)
 set(PYBIND11_TEST_FILES
-  test_async.cpp
-  test_buffers.cpp
-  test_builtin_casters.cpp
-  test_call_policies.cpp
-  test_callbacks.cpp
-  test_chrono.cpp
-  test_class.cpp
-  test_constants_and_functions.cpp
-  test_copy_move.cpp
-  test_custom_type_casters.cpp
-  test_docstring_options.cpp
-  test_eigen.cpp
-  test_enum.cpp
-  test_eval.cpp
-  test_exceptions.cpp
-  test_factory_constructors.cpp
-  test_gil_scoped.cpp
-  test_iostream.cpp
-  test_kwargs_and_defaults.cpp
-  test_local_bindings.cpp
-  test_methods_and_attributes.cpp
-  test_modules.cpp
-  test_multiple_inheritance.cpp
-  test_numpy_array.cpp
-  test_numpy_dtypes.cpp
-  test_numpy_vectorize.cpp
-  test_opaque_types.cpp
-  test_operator_overloading.cpp
-  test_pickling.cpp
-  test_pytypes.cpp
-  test_sequences_and_iterators.cpp
-  test_smart_ptr.cpp
-  test_stl.cpp
-  test_stl_binders.cpp
-  test_tagbased_polymorphic.cpp
-  test_union.cpp
-  test_virtual_functions.cpp
-)
+    test_async.cpp
+    test_buffers.cpp
+    test_builtin_casters.cpp
+    test_call_policies.cpp
+    test_callbacks.cpp
+    test_chrono.cpp
+    test_class.cpp
+    test_constants_and_functions.cpp
+    test_copy_move.cpp
+    test_custom_type_casters.cpp
+    test_docstring_options.cpp
+    test_eigen.cpp
+    test_enum.cpp
+    test_eval.cpp
+    test_exceptions.cpp
+    test_factory_constructors.cpp
+    test_gil_scoped.cpp
+    test_iostream.cpp
+    test_kwargs_and_defaults.cpp
+    test_local_bindings.cpp
+    test_methods_and_attributes.cpp
+    test_modules.cpp
+    test_multiple_inheritance.cpp
+    test_numpy_array.cpp
+    test_numpy_dtypes.cpp
+    test_numpy_vectorize.cpp
+    test_opaque_types.cpp
+    test_operator_overloading.cpp
+    test_pickling.cpp
+    test_pytypes.cpp
+    test_sequences_and_iterators.cpp
+    test_smart_ptr.cpp
+    test_stl.cpp
+    test_stl_binders.cpp
+    test_tagbased_polymorphic.cpp
+    test_union.cpp
+    test_virtual_functions.cpp)
 
 # Invoking cmake with something like:
 #     cmake -DPYBIND11_TEST_OVERRIDE="test_callbacks.cpp;test_picking.cpp" ..
 # lets you override the tests that get compiled and run.  You can restore to all tests with:
 #     cmake -DPYBIND11_TEST_OVERRIDE= ..
-if (PYBIND11_TEST_OVERRIDE)
+if(PYBIND11_TEST_OVERRIDE)
   set(PYBIND11_TEST_FILES ${PYBIND11_TEST_OVERRIDE})
 endif()
 
 # Skip test_async for Python < 3.5
 list(FIND PYBIND11_TEST_FILES test_async.cpp PYBIND11_TEST_FILES_ASYNC_I)
-if((PYBIND11_TEST_FILES_ASYNC_I GREATER -1) AND ("${PYTHON_VERSION_MAJOR}.${PYTHON_VERSION_MINOR}" VERSION_LESS 3.5))
-  message(STATUS "Skipping test_async because Python version ${PYTHON_VERSION_MAJOR}.${PYTHON_VERSION_MINOR} < 3.5")
+if((PYBIND11_TEST_FILES_ASYNC_I GREATER -1) AND ("${PYTHON_VERSION_MAJOR}.${PYTHON_VERSION_MINOR}"
+                                                 VERSION_LESS 3.5))
+  message(
+    STATUS
+      "Skipping test_async because Python version ${PYTHON_VERSION_MAJOR}.${PYTHON_VERSION_MINOR} < 3.5"
+  )
   list(REMOVE_AT PYBIND11_TEST_FILES ${PYBIND11_TEST_FILES_ASYNC_I})
 endif()
 
@@ -96,16 +103,10 @@ string(REPLACE ".cpp" ".py" PYBIND11_PYTEST_FILES "${PYBIND11_TEST_FILES}")
 # Contains the set of test files that require pybind11_cross_module_tests to be
 # built; if none of these are built (i.e. because TEST_OVERRIDE is used and
 # doesn't include them) the second module doesn't get built.
-set(PYBIND11_CROSS_MODULE_TESTS
-  test_exceptions.py
-  test_local_bindings.py
-  test_stl.py
-  test_stl_binders.py
-)
+set(PYBIND11_CROSS_MODULE_TESTS test_exceptions.py test_local_bindings.py test_stl.py
+                                test_stl_binders.py)
 
-set(PYBIND11_CROSS_MODULE_GIL_TESTS
-  test_gil_scoped.py
-)
+set(PYBIND11_CROSS_MODULE_GIL_TESTS test_gil_scoped.py)
 
 # Check if Eigen is available; if not, remove from PYBIND11_TEST_FILES (but
 # keep it in PYBIND11_PYTEST_FILES, so that we get the "eigen is not installed"
@@ -126,8 +127,7 @@ if(PYBIND11_TEST_FILES_EIGEN_I GREATER -1)
     FetchContent_Declare(
       eigen
       GIT_REPOSITORY https://gitlab.com/libeigen/eigen.git
-      GIT_TAG ${EIGEN3_VERSION_STRING}
-    )
+      GIT_TAG ${EIGEN3_VERSION_STRING})
 
     FetchContent_GetProperties(eigen)
     if(NOT eigen_POPULATED)
@@ -139,13 +139,13 @@ if(PYBIND11_TEST_FILES_EIGEN_I GREATER -1)
     set(EIGEN3_FOUND TRUE)
   else()
     find_package(Eigen3 3.2.7 QUIET CONFIG)
-    if (EIGEN3_FOUND)
-      if (EIGEN3_VERSION_STRING AND NOT EIGEN3_VERSION_STRING VERSION_LESS 3.3.1)
+    if(EIGEN3_FOUND)
+      if(EIGEN3_VERSION_STRING AND NOT EIGEN3_VERSION_STRING VERSION_LESS 3.3.1)
         set(PYBIND11_EIGEN_VIA_TARGET TRUE)
       endif()
     endif()
 
-    if (NOT EIGEN3_FOUND)
+    if(NOT EIGEN3_FOUND)
       # Couldn't load via target, so fall back to allowing module mode finding, which will pick up
       # tools/FindEigen3.cmake
       find_package(Eigen3 3.2.7 QUIET)
@@ -174,7 +174,8 @@ function(pybind11_enable_warnings target_name)
   if(MSVC)
     target_compile_options(${target_name} PRIVATE /W4)
   elseif(CMAKE_CXX_COMPILER_ID MATCHES "(GNU|Intel|Clang)")
-      target_compile_options(${target_name} PRIVATE -Wall -Wextra -Wconversion -Wcast-qual -Wdeprecated)
+    target_compile_options(${target_name} PRIVATE -Wall -Wextra -Wconversion -Wcast-qual
+                                                  -Wdeprecated)
   endif()
 
   if(PYBIND11_WERROR)
@@ -186,7 +187,9 @@ function(pybind11_enable_warnings target_name)
   endif()
 
   # Needs to be readded since the ordering requires these to be after the ones above
-  if(CMAKE_CXX_STANDARD AND CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND PYTHON_VERSION VERSION_LESS 3.0)
+  if(CMAKE_CXX_STANDARD
+     AND CMAKE_CXX_COMPILER_ID MATCHES "Clang"
+     AND PYTHON_VERSION VERSION_LESS 3.0)
     if(CMAKE_CXX_STANDARD LESS 17)
       target_compile_options(${target_name} PUBLIC -Wno-deprecated-register)
     else()
@@ -200,7 +203,7 @@ set(test_targets pybind11_tests)
 # Build pybind11_cross_module_tests if any test_whatever.py are being built that require it
 foreach(t ${PYBIND11_CROSS_MODULE_TESTS})
   list(FIND PYBIND11_PYTEST_FILES ${t} i)
-  if (i GREATER -1)
+  if(i GREATER -1)
     list(APPEND test_targets pybind11_cross_module_tests)
     break()
   endif()
@@ -208,7 +211,7 @@ endforeach()
 
 foreach(t ${PYBIND11_CROSS_MODULE_GIL_TESTS})
   list(FIND PYBIND11_PYTEST_FILES ${t} i)
-  if (i GREATER -1)
+  if(i GREATER -1)
     list(APPEND test_targets cross_module_gil_utils)
     break()
   endif()
@@ -230,7 +233,7 @@ foreach(target ${test_targets})
   endif()
 
   if(EIGEN3_FOUND)
-    if (PYBIND11_EIGEN_VIA_TARGET)
+    if(PYBIND11_EIGEN_VIA_TARGET)
       target_link_libraries(${target} PRIVATE Eigen3::Eigen)
     else()
       target_include_directories(${target} PRIVATE ${EIGEN3_INCLUDE_DIR})
@@ -255,8 +258,11 @@ endforeach()
 
 # Make sure pytest is found or produce a fatal error
 if(NOT PYBIND11_PYTEST_FOUND)
-  execute_process(COMMAND ${PYTHON_EXECUTABLE} -c "import pytest; print(pytest.__version__)"
-                  RESULT_VARIABLE pytest_not_found OUTPUT_VARIABLE pytest_version ERROR_QUIET)
+  execute_process(
+    COMMAND ${PYTHON_EXECUTABLE} -c "import pytest; print(pytest.__version__)"
+    RESULT_VARIABLE pytest_not_found
+    OUTPUT_VARIABLE pytest_version
+    ERROR_QUIET)
   if(pytest_not_found)
     message(FATAL_ERROR "Running the tests requires pytest. Please install it manually"
                         " (try: ${PYTHON_EXECUTABLE} -m pip install pytest)")
@@ -264,16 +270,25 @@ if(NOT PYBIND11_PYTEST_FOUND)
     message(FATAL_ERROR "Running the tests requires pytest >= 3.0. Found: ${pytest_version}"
                         "Please update it (try: ${PYTHON_EXECUTABLE} -m pip install -U pytest)")
   endif()
-  set(PYBIND11_PYTEST_FOUND TRUE CACHE INTERNAL "")
+  set(PYBIND11_PYTEST_FOUND
+      TRUE
+      CACHE INTERNAL "")
 endif()
 
 # A single command to compile and run the tests
-add_custom_target(pytest COMMAND ${PYTHON_EXECUTABLE} -m pytest ${PYBIND11_PYTEST_FILES}
-                  DEPENDS ${test_targets} WORKING_DIRECTORY ${testdir} USES_TERMINAL)
+add_custom_target(
+  pytest
+  COMMAND ${PYTHON_EXECUTABLE} -m pytest ${PYBIND11_PYTEST_FILES}
+  DEPENDS ${test_targets}
+  WORKING_DIRECTORY ${testdir}
+  USES_TERMINAL)
 
 if(PYBIND11_TEST_OVERRIDE)
-  add_custom_command(TARGET pytest POST_BUILD
-    COMMAND ${CMAKE_COMMAND} -E echo "Note: not all tests run: -DPYBIND11_TEST_OVERRIDE is in effect")
+  add_custom_command(
+    TARGET pytest
+    POST_BUILD
+    COMMAND ${CMAKE_COMMAND} -E echo
+            "Note: not all tests run: -DPYBIND11_TEST_OVERRIDE is in effect")
 endif()
 
 # Add a check target to run all the tests, starting with pytest (we add dependencies to this below)
@@ -287,11 +302,10 @@ endif()
 
 # Add a post-build comment to show the primary test suite .so size and, if a previous size, compare it:
 add_custom_command(
-  TARGET
-    pybind11_tests
-  POST_BUILD COMMAND
-    ${PYTHON_EXECUTABLE}
-    ${CMAKE_CURRENT_SOURCE_DIR}/../tools/libsize.py
+  TARGET pybind11_tests
+  POST_BUILD
+  COMMAND
+    ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/../tools/libsize.py
     $<TARGET_FILE:pybind11_tests>
     ${CMAKE_CURRENT_BINARY_DIR}/sosize-$<TARGET_FILE_NAME:pybind11_tests>.txt)
 
diff --git a/tests/test_cmake_build/CMakeLists.txt b/tests/test_cmake_build/CMakeLists.txt
index fd8c80304..53228f0eb 100644
--- a/tests/test_cmake_build/CMakeLists.txt
+++ b/tests/test_cmake_build/CMakeLists.txt
@@ -1,12 +1,12 @@
 add_custom_target(test_cmake_build)
 
-
 function(pybind11_add_build_test name)
   cmake_parse_arguments(ARG "INSTALL" "" "" ${ARGN})
 
-  set(build_options "-DCMAKE_PREFIX_PATH=${pybind11_BINARY_DIR}/mock_install"
-                    "-DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}"
-                    "-DPYTHON_EXECUTABLE:FILEPATH=${PYTHON_EXECUTABLE}")
+  set(build_options
+      "-DCMAKE_PREFIX_PATH=${pybind11_BINARY_DIR}/mock_install"
+      "-DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}"
+      "-DPYTHON_EXECUTABLE:FILEPATH=${PYTHON_EXECUTABLE}")
 
   if(CMAKE_CXX_STANDARD)
     list(APPEND build_options "-DCMAKE_CXX_STANDARD=${CMAKE_CXX_STANDARD}")
@@ -16,17 +16,25 @@ function(pybind11_add_build_test name)
     list(APPEND build_options "-DPYBIND11_PROJECT_DIR=${pybind11_SOURCE_DIR}")
   endif()
 
-  add_custom_target(test_${name} ${CMAKE_CTEST_COMMAND}
-    --build-and-test "${CMAKE_CURRENT_SOURCE_DIR}/${name}"
-                     "${CMAKE_CURRENT_BINARY_DIR}/${name}"
-    --build-config Release
+  add_custom_target(
+    test_${name}
+    ${CMAKE_CTEST_COMMAND}
+    --build-and-test
+    "${CMAKE_CURRENT_SOURCE_DIR}/${name}"
+    "${CMAKE_CURRENT_BINARY_DIR}/${name}"
+    --build-config
+    Release
     --build-noclean
-    --build-generator ${CMAKE_GENERATOR}
-    $<$<BOOL:${CMAKE_GENERATOR_PLATFORM}>:--build-generator-platform> ${CMAKE_GENERATOR_PLATFORM}
-    --build-makeprogram ${CMAKE_MAKE_PROGRAM}
-    --build-target check
-    --build-options ${build_options}
-  )
+    --build-generator
+    ${CMAKE_GENERATOR}
+    $<$<BOOL:${CMAKE_GENERATOR_PLATFORM}>:--build-generator-platform>
+    ${CMAKE_GENERATOR_PLATFORM}
+    --build-makeprogram
+    ${CMAKE_MAKE_PROGRAM}
+    --build-target
+    check
+    --build-options
+    ${build_options})
   if(ARG_INSTALL)
     add_dependencies(test_${name} mock_install)
   endif()
@@ -40,10 +48,9 @@ if(NOT ${PYTHON_MODULE_EXTENSION} MATCHES "pypy")
 endif()
 
 if(PYBIND11_INSTALL)
-  add_custom_target(mock_install ${CMAKE_COMMAND}
-    "-DCMAKE_INSTALL_PREFIX=${pybind11_BINARY_DIR}/mock_install"
-    -P "${pybind11_BINARY_DIR}/cmake_install.cmake"
-  )
+  add_custom_target(
+    mock_install ${CMAKE_COMMAND} "-DCMAKE_INSTALL_PREFIX=${pybind11_BINARY_DIR}/mock_install" -P
+                 "${pybind11_BINARY_DIR}/cmake_install.cmake")
 
   pybind11_add_build_test(installed_function INSTALL)
   pybind11_add_build_test(installed_target INSTALL)
diff --git a/tests/test_cmake_build/installed_embed/CMakeLists.txt b/tests/test_cmake_build/installed_embed/CMakeLists.txt
index 80ac2f0e9..78855afa2 100644
--- a/tests/test_cmake_build/installed_embed/CMakeLists.txt
+++ b/tests/test_cmake_build/installed_embed/CMakeLists.txt
@@ -8,7 +8,6 @@ message(STATUS "Found pybind11 v${pybind11_VERSION}: ${pybind11_INCLUDE_DIRS}")
 add_executable(test_cmake_build ../embed.cpp)
 target_link_libraries(test_cmake_build PRIVATE pybind11::embed)
 
-
 # Do not treat includes from IMPORTED target as SYSTEM (Python headers in pybind11::embed).
 # This may be needed to resolve header conflicts, e.g. between Python release and debug headers.
 set_target_properties(test_cmake_build PROPERTIES NO_SYSTEM_FROM_IMPORTED ON)
diff --git a/tests/test_cmake_build/installed_function/CMakeLists.txt b/tests/test_cmake_build/installed_function/CMakeLists.txt
index a8c0130d9..3ad5445e3 100644
--- a/tests/test_cmake_build/installed_function/CMakeLists.txt
+++ b/tests/test_cmake_build/installed_function/CMakeLists.txt
@@ -8,5 +8,12 @@ message(STATUS "Found pybind11 v${pybind11_VERSION}: ${pybind11_INCLUDE_DIRS}")
 
 pybind11_add_module(test_cmake_build SHARED NO_EXTRAS ../main.cpp)
 
-add_custom_target(check ${CMAKE_COMMAND} -E env PYTHONPATH=$<TARGET_FILE_DIR:test_cmake_build>
-                  ${PYTHON_EXECUTABLE} ${PROJECT_SOURCE_DIR}/../test.py ${PROJECT_NAME})
+add_custom_target(
+  check
+  ${CMAKE_COMMAND}
+  -E
+  env
+  PYTHONPATH=$<TARGET_FILE_DIR:test_cmake_build>
+  ${PYTHON_EXECUTABLE}
+  ${PROJECT_SOURCE_DIR}/../test.py
+  ${PROJECT_NAME})
diff --git a/tests/test_cmake_build/installed_target/CMakeLists.txt b/tests/test_cmake_build/installed_target/CMakeLists.txt
index a172c20cf..348c419cd 100644
--- a/tests/test_cmake_build/installed_target/CMakeLists.txt
+++ b/tests/test_cmake_build/installed_target/CMakeLists.txt
@@ -18,5 +18,12 @@ set_target_properties(test_cmake_build PROPERTIES PREFIX "${PYTHON_MODULE_PREFIX
 # This may be needed to resolve header conflicts, e.g. between Python release and debug headers.
 set_target_properties(test_cmake_build PROPERTIES NO_SYSTEM_FROM_IMPORTED ON)
 
-add_custom_target(check ${CMAKE_COMMAND} -E env PYTHONPATH=$<TARGET_FILE_DIR:test_cmake_build>
-                  ${PYTHON_EXECUTABLE} ${PROJECT_SOURCE_DIR}/../test.py ${PROJECT_NAME})
+add_custom_target(
+  check
+  ${CMAKE_COMMAND}
+  -E
+  env
+  PYTHONPATH=$<TARGET_FILE_DIR:test_cmake_build>
+  ${PYTHON_EXECUTABLE}
+  ${PROJECT_SOURCE_DIR}/../test.py
+  ${PROJECT_NAME})
diff --git a/tests/test_cmake_build/subdirectory_embed/CMakeLists.txt b/tests/test_cmake_build/subdirectory_embed/CMakeLists.txt
index 170ec5300..eea0eeea3 100644
--- a/tests/test_cmake_build/subdirectory_embed/CMakeLists.txt
+++ b/tests/test_cmake_build/subdirectory_embed/CMakeLists.txt
@@ -1,7 +1,9 @@
 cmake_minimum_required(VERSION 3.7)
 project(test_subdirectory_embed CXX)
 
-set(PYBIND11_INSTALL ON CACHE BOOL "")
+set(PYBIND11_INSTALL
+    ON
+    CACHE BOOL "")
 set(PYBIND11_EXPORT_NAME test_export)
 
 add_subdirectory(${PYBIND11_PROJECT_DIR} pybind11)
@@ -16,10 +18,10 @@ add_custom_target(check $<TARGET_FILE:test_cmake_build> ${PROJECT_SOURCE_DIR}/..
 add_library(test_embed_lib ../embed.cpp)
 target_link_libraries(test_embed_lib PRIVATE pybind11::embed)
 
-install(TARGETS test_embed_lib
-        EXPORT  test_export
-        ARCHIVE DESTINATION bin
-        LIBRARY DESTINATION lib
-        RUNTIME DESTINATION lib)
-install(EXPORT      test_export
-        DESTINATION lib/cmake/test_export/test_export-Targets.cmake)
+install(
+  TARGETS test_embed_lib
+  EXPORT test_export
+  ARCHIVE DESTINATION bin
+  LIBRARY DESTINATION lib
+  RUNTIME DESTINATION lib)
+install(EXPORT test_export DESTINATION lib/cmake/test_export/test_export-Targets.cmake)
diff --git a/tests/test_cmake_build/subdirectory_function/CMakeLists.txt b/tests/test_cmake_build/subdirectory_function/CMakeLists.txt
index f4d4e3583..e4518044e 100644
--- a/tests/test_cmake_build/subdirectory_function/CMakeLists.txt
+++ b/tests/test_cmake_build/subdirectory_function/CMakeLists.txt
@@ -4,5 +4,12 @@ project(test_subdirectory_module CXX)
 add_subdirectory(${PYBIND11_PROJECT_DIR} pybind11)
 pybind11_add_module(test_cmake_build THIN_LTO ../main.cpp)
 
-add_custom_target(check ${CMAKE_COMMAND} -E env PYTHONPATH=$<TARGET_FILE_DIR:test_cmake_build>
-                  ${PYTHON_EXECUTABLE} ${PROJECT_SOURCE_DIR}/../test.py ${PROJECT_NAME})
+add_custom_target(
+  check
+  ${CMAKE_COMMAND}
+  -E
+  env
+  PYTHONPATH=$<TARGET_FILE_DIR:test_cmake_build>
+  ${PYTHON_EXECUTABLE}
+  ${PROJECT_SOURCE_DIR}/../test.py
+  ${PROJECT_NAME})
diff --git a/tests/test_cmake_build/subdirectory_target/CMakeLists.txt b/tests/test_cmake_build/subdirectory_target/CMakeLists.txt
index 01acba426..f84140ce0 100644
--- a/tests/test_cmake_build/subdirectory_target/CMakeLists.txt
+++ b/tests/test_cmake_build/subdirectory_target/CMakeLists.txt
@@ -11,5 +11,12 @@ target_link_libraries(test_cmake_build PRIVATE pybind11::module)
 set_target_properties(test_cmake_build PROPERTIES PREFIX "${PYTHON_MODULE_PREFIX}"
                                                   SUFFIX "${PYTHON_MODULE_EXTENSION}")
 
-add_custom_target(check ${CMAKE_COMMAND} -E env PYTHONPATH=$<TARGET_FILE_DIR:test_cmake_build>
-                  ${PYTHON_EXECUTABLE} ${PROJECT_SOURCE_DIR}/../test.py ${PROJECT_NAME})
+add_custom_target(
+  check
+  ${CMAKE_COMMAND}
+  -E
+  env
+  PYTHONPATH=$<TARGET_FILE_DIR:test_cmake_build>
+  ${PYTHON_EXECUTABLE}
+  ${PROJECT_SOURCE_DIR}/../test.py
+  ${PROJECT_NAME})
diff --git a/tests/test_embed/CMakeLists.txt b/tests/test_embed/CMakeLists.txt
index 495b0fcbf..25972701f 100644
--- a/tests/test_embed/CMakeLists.txt
+++ b/tests/test_embed/CMakeLists.txt
@@ -1,5 +1,5 @@
 if(${PYTHON_MODULE_EXTENSION} MATCHES "pypy")
-  add_custom_target(cpptest)  # Dummy target on PyPy. Embedding is not supported.
+  add_custom_target(cpptest) # Dummy target on PyPy. Embedding is not supported.
   set(_suppress_unused_variable_warning "${DOWNLOAD_CATCH}")
   return()
 endif()
@@ -13,10 +13,7 @@ else()
   return()
 endif()
 
-add_executable(test_embed
-  catch.cpp
-  test_interpreter.cpp
-)
+add_executable(test_embed catch.cpp test_interpreter.cpp)
 target_include_directories(test_embed PRIVATE "${CATCH_INCLUDE_DIR}")
 pybind11_enable_warnings(test_embed)
 
@@ -25,14 +22,18 @@ target_link_libraries(test_embed PRIVATE pybind11::embed)
 find_package(Threads REQUIRED)
 target_link_libraries(test_embed PUBLIC Threads::Threads)
 
-add_custom_target(cpptest COMMAND "$<TARGET_FILE:test_embed>"
-                  WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}")
+add_custom_target(
+  cpptest
+  COMMAND "$<TARGET_FILE:test_embed>"
+  WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}")
 
 pybind11_add_module(external_module THIN_LTO external_module.cpp)
-set_target_properties(external_module PROPERTIES LIBRARY_OUTPUT_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}")
+set_target_properties(external_module PROPERTIES LIBRARY_OUTPUT_DIRECTORY
+                                                 "${CMAKE_CURRENT_SOURCE_DIR}")
 foreach(config ${CMAKE_CONFIGURATION_TYPES})
   string(TOUPPER ${config} config)
-  set_target_properties(external_module PROPERTIES LIBRARY_OUTPUT_DIRECTORY_${config} "${CMAKE_CURRENT_SOURCE_DIR}")
+  set_target_properties(external_module PROPERTIES LIBRARY_OUTPUT_DIRECTORY_${config}
+                                                   "${CMAKE_CURRENT_SOURCE_DIR}")
 endforeach()
 add_dependencies(cpptest external_module)
 
diff --git a/tools/FindCatch.cmake b/tools/FindCatch.cmake
index ad4a4a593..ade66c79e 100644
--- a/tools/FindCatch.cmake
+++ b/tools/FindCatch.cmake
@@ -19,9 +19,14 @@ endif()
 
 # Extract the version number from catch.hpp
 function(_get_catch_version)
-  file(STRINGS "${CATCH_INCLUDE_DIR}/catch.hpp" version_line REGEX "Catch v.*" LIMIT_COUNT 1)
+  file(
+    STRINGS "${CATCH_INCLUDE_DIR}/catch.hpp" version_line
+    REGEX "Catch v.*"
+    LIMIT_COUNT 1)
   if(version_line MATCHES "Catch v([0-9]+)\\.([0-9]+)\\.([0-9]+)")
-    set(CATCH_VERSION "${CMAKE_MATCH_1}.${CMAKE_MATCH_2}.${CMAKE_MATCH_3}" PARENT_SCOPE)
+    set(CATCH_VERSION
+        "${CMAKE_MATCH_1}.${CMAKE_MATCH_2}.${CMAKE_MATCH_3}"
+        PARENT_SCOPE)
   endif()
 endfunction()
 
@@ -34,11 +39,16 @@ function(_download_catch version destination_dir)
   if(error)
     message(FATAL_ERROR "Could not download ${url}")
   endif()
-  set(CATCH_INCLUDE_DIR "${destination_dir}" CACHE INTERNAL "")
+  set(CATCH_INCLUDE_DIR
+      "${destination_dir}"
+      CACHE INTERNAL "")
 endfunction()
 
 # Look for catch locally
-find_path(CATCH_INCLUDE_DIR NAMES catch.hpp PATH_SUFFIXES catch2)
+find_path(
+  CATCH_INCLUDE_DIR
+  NAMES catch.hpp
+  PATH_SUFFIXES catch2)
 if(CATCH_INCLUDE_DIR)
   _get_catch_version()
 endif()
diff --git a/tools/FindEigen3.cmake b/tools/FindEigen3.cmake
index 66ffe8e1e..98ab43d9e 100644
--- a/tools/FindEigen3.cmake
+++ b/tools/FindEigen3.cmake
@@ -26,17 +26,21 @@ if(NOT Eigen3_FIND_VERSION)
     set(Eigen3_FIND_VERSION_PATCH 0)
   endif(NOT Eigen3_FIND_VERSION_PATCH)
 
-  set(Eigen3_FIND_VERSION "${Eigen3_FIND_VERSION_MAJOR}.${Eigen3_FIND_VERSION_MINOR}.${Eigen3_FIND_VERSION_PATCH}")
+  set(Eigen3_FIND_VERSION
+      "${Eigen3_FIND_VERSION_MAJOR}.${Eigen3_FIND_VERSION_MINOR}.${Eigen3_FIND_VERSION_PATCH}")
 endif(NOT Eigen3_FIND_VERSION)
 
 macro(_eigen3_check_version)
   file(READ "${EIGEN3_INCLUDE_DIR}/Eigen/src/Core/util/Macros.h" _eigen3_version_header)
 
-  string(REGEX MATCH "define[ \t]+EIGEN_WORLD_VERSION[ \t]+([0-9]+)" _eigen3_world_version_match "${_eigen3_version_header}")
+  string(REGEX MATCH "define[ \t]+EIGEN_WORLD_VERSION[ \t]+([0-9]+)" _eigen3_world_version_match
+               "${_eigen3_version_header}")
   set(EIGEN3_WORLD_VERSION "${CMAKE_MATCH_1}")
-  string(REGEX MATCH "define[ \t]+EIGEN_MAJOR_VERSION[ \t]+([0-9]+)" _eigen3_major_version_match "${_eigen3_version_header}")
+  string(REGEX MATCH "define[ \t]+EIGEN_MAJOR_VERSION[ \t]+([0-9]+)" _eigen3_major_version_match
+               "${_eigen3_version_header}")
   set(EIGEN3_MAJOR_VERSION "${CMAKE_MATCH_1}")
-  string(REGEX MATCH "define[ \t]+EIGEN_MINOR_VERSION[ \t]+([0-9]+)" _eigen3_minor_version_match "${_eigen3_version_header}")
+  string(REGEX MATCH "define[ \t]+EIGEN_MINOR_VERSION[ \t]+([0-9]+)" _eigen3_minor_version_match
+               "${_eigen3_version_header}")
   set(EIGEN3_MINOR_VERSION "${CMAKE_MATCH_1}")
 
   set(EIGEN3_VERSION ${EIGEN3_WORLD_VERSION}.${EIGEN3_MAJOR_VERSION}.${EIGEN3_MINOR_VERSION})
@@ -53,20 +57,19 @@ macro(_eigen3_check_version)
   endif(NOT EIGEN3_VERSION_OK)
 endmacro(_eigen3_check_version)
 
-if (EIGEN3_INCLUDE_DIR)
+if(EIGEN3_INCLUDE_DIR)
 
   # in cache already
   _eigen3_check_version()
   set(EIGEN3_FOUND ${EIGEN3_VERSION_OK})
 
-else (EIGEN3_INCLUDE_DIR)
+else(EIGEN3_INCLUDE_DIR)
 
-  find_path(EIGEN3_INCLUDE_DIR NAMES signature_of_eigen3_matrix_library
-      PATHS
-      ${CMAKE_INSTALL_PREFIX}/include
-      ${KDE4_INCLUDE_DIR}
-      PATH_SUFFIXES eigen3 eigen
-    )
+  find_path(
+    EIGEN3_INCLUDE_DIR
+    NAMES signature_of_eigen3_matrix_library
+    PATHS ${CMAKE_INSTALL_PREFIX}/include ${KDE4_INCLUDE_DIR}
+    PATH_SUFFIXES eigen3 eigen)
 
   if(EIGEN3_INCLUDE_DIR)
     _eigen3_check_version()
diff --git a/tools/FindPythonLibsNew.cmake b/tools/FindPythonLibsNew.cmake
index 994bb1e03..cf2a13f67 100644
--- a/tools/FindPythonLibsNew.cmake
+++ b/tools/FindPythonLibsNew.cmake
@@ -52,23 +52,23 @@
 
 # Checking for the extension makes sure that `LibsNew` was found and not just `Libs`.
 if(PYTHONLIBS_FOUND AND PYTHON_MODULE_EXTENSION)
-    return()
+  return()
 endif()
 
 # Use the Python interpreter to find the libs.
 if(NOT PythonLibsNew_FIND_VERSION)
-    set(PythonLibsNew_FIND_VERSION "")
+  set(PythonLibsNew_FIND_VERSION "")
 endif()
 if(PythonLibsNew_FIND_REQUIRED)
-    find_package(PythonInterp ${PythonLibsNew_FIND_VERSION} REQUIRED)
+  find_package(PythonInterp ${PythonLibsNew_FIND_VERSION} REQUIRED)
 else()
-    find_package(PythonInterp ${PythonLibsNew_FIND_VERSION})
+  find_package(PythonInterp ${PythonLibsNew_FIND_VERSION})
 endif()
 
 if(NOT PYTHONINTERP_FOUND)
-    set(PYTHONLIBS_FOUND FALSE)
-    set(PythonLibsNew_FOUND FALSE)
-    return()
+  set(PYTHONLIBS_FOUND FALSE)
+  set(PythonLibsNew_FOUND FALSE)
+  return()
 endif()
 
 # According to http://stackoverflow.com/questions/646518/python-how-to-detect-debug-interpreter
@@ -77,8 +77,9 @@ endif()
 #
 # The library suffix is from the config var LDVERSION sometimes, otherwise
 # VERSION. VERSION will typically be like "2.7" on unix, and "27" on windows.
-execute_process(COMMAND "${PYTHON_EXECUTABLE}" "-c"
-    "from distutils import sysconfig as s;import sys;import struct;
+execute_process(
+  COMMAND
+    "${PYTHON_EXECUTABLE}" "-c" "from distutils import sysconfig as s;import sys;import struct;
 print('.'.join(str(v) for v in sys.version_info));
 print(sys.prefix);
 print(s.get_python_inc(plat_specific=True));
@@ -90,23 +91,22 @@ print(s.get_config_var('LDVERSION') or s.get_config_var('VERSION'));
 print(s.get_config_var('LIBDIR') or '');
 print(s.get_config_var('MULTIARCH') or '');
 "
-    RESULT_VARIABLE _PYTHON_SUCCESS
-    OUTPUT_VARIABLE _PYTHON_VALUES
-    ERROR_VARIABLE _PYTHON_ERROR_VALUE)
+  RESULT_VARIABLE _PYTHON_SUCCESS
+  OUTPUT_VARIABLE _PYTHON_VALUES
+  ERROR_VARIABLE _PYTHON_ERROR_VALUE)
 
 if(NOT _PYTHON_SUCCESS MATCHES 0)
-    if(PythonLibsNew_FIND_REQUIRED)
-        message(FATAL_ERROR
-            "Python config failure:\n${_PYTHON_ERROR_VALUE}")
-    endif()
-    set(PYTHONLIBS_FOUND FALSE)
-    set(PythonLibsNew_FOUND FALSE)
-    return()
+  if(PythonLibsNew_FIND_REQUIRED)
+    message(FATAL_ERROR "Python config failure:\n${_PYTHON_ERROR_VALUE}")
+  endif()
+  set(PYTHONLIBS_FOUND FALSE)
+  set(PythonLibsNew_FOUND FALSE)
+  return()
 endif()
 
 # Convert the process output into a list
 if(WIN32)
-    string(REGEX REPLACE "\\\\" "/" _PYTHON_VALUES ${_PYTHON_VALUES})
+  string(REGEX REPLACE "\\\\" "/" _PYTHON_VALUES ${_PYTHON_VALUES})
 endif()
 string(REGEX REPLACE ";" "\\\\;" _PYTHON_VALUES ${_PYTHON_VALUES})
 string(REGEX REPLACE "\n" ";" _PYTHON_VALUES ${_PYTHON_VALUES})
@@ -124,16 +124,15 @@ list(GET _PYTHON_VALUES 9 PYTHON_MULTIARCH)
 # Make sure the Python has the same pointer-size as the chosen compiler
 # Skip if CMAKE_SIZEOF_VOID_P is not defined
 if(CMAKE_SIZEOF_VOID_P AND (NOT "${PYTHON_SIZEOF_VOID_P}" STREQUAL "${CMAKE_SIZEOF_VOID_P}"))
-    if(PythonLibsNew_FIND_REQUIRED)
-        math(EXPR _PYTHON_BITS "${PYTHON_SIZEOF_VOID_P} * 8")
-        math(EXPR _CMAKE_BITS "${CMAKE_SIZEOF_VOID_P} * 8")
-        message(FATAL_ERROR
-            "Python config failure: Python is ${_PYTHON_BITS}-bit, "
-            "chosen compiler is  ${_CMAKE_BITS}-bit")
-    endif()
-    set(PYTHONLIBS_FOUND FALSE)
-    set(PythonLibsNew_FOUND FALSE)
-    return()
+  if(PythonLibsNew_FIND_REQUIRED)
+    math(EXPR _PYTHON_BITS "${PYTHON_SIZEOF_VOID_P} * 8")
+    math(EXPR _CMAKE_BITS "${CMAKE_SIZEOF_VOID_P} * 8")
+    message(FATAL_ERROR "Python config failure: Python is ${_PYTHON_BITS}-bit, "
+                        "chosen compiler is  ${_CMAKE_BITS}-bit")
+  endif()
+  set(PYTHONLIBS_FOUND FALSE)
+  set(PythonLibsNew_FOUND FALSE)
+  return()
 endif()
 
 # The built-in FindPython didn't always give the version numbers
@@ -148,79 +147,76 @@ string(REGEX REPLACE "\\\\" "/" PYTHON_INCLUDE_DIR "${PYTHON_INCLUDE_DIR}")
 string(REGEX REPLACE "\\\\" "/" PYTHON_SITE_PACKAGES "${PYTHON_SITE_PACKAGES}")
 
 if(CMAKE_HOST_WIN32)
-    set(PYTHON_LIBRARY
-        "${PYTHON_PREFIX}/libs/python${PYTHON_LIBRARY_SUFFIX}.lib")
+  set(PYTHON_LIBRARY "${PYTHON_PREFIX}/libs/python${PYTHON_LIBRARY_SUFFIX}.lib")
 
-    # when run in a venv, PYTHON_PREFIX points to it. But the libraries remain in the
-    # original python installation. They may be found relative to PYTHON_INCLUDE_DIR.
-    if(NOT EXISTS "${PYTHON_LIBRARY}")
-        get_filename_component(_PYTHON_ROOT ${PYTHON_INCLUDE_DIR} DIRECTORY)
-        set(PYTHON_LIBRARY
-            "${_PYTHON_ROOT}/libs/python${PYTHON_LIBRARY_SUFFIX}.lib")
-    endif()
+  # when run in a venv, PYTHON_PREFIX points to it. But the libraries remain in the
+  # original python installation. They may be found relative to PYTHON_INCLUDE_DIR.
+  if(NOT EXISTS "${PYTHON_LIBRARY}")
+    get_filename_component(_PYTHON_ROOT ${PYTHON_INCLUDE_DIR} DIRECTORY)
+    set(PYTHON_LIBRARY "${_PYTHON_ROOT}/libs/python${PYTHON_LIBRARY_SUFFIX}.lib")
+  endif()
 
-    # if we are in MSYS & MINGW, and we didn't find windows python lib, look for system python lib
-    if(DEFINED ENV{MSYSTEM} AND MINGW AND NOT EXISTS "${PYTHON_LIBRARY}")
-        if(PYTHON_MULTIARCH)
-            set(_PYTHON_LIBS_SEARCH "${PYTHON_LIBDIR}/${PYTHON_MULTIARCH}" "${PYTHON_LIBDIR}")
-        else()
-            set(_PYTHON_LIBS_SEARCH "${PYTHON_LIBDIR}")
-        endif()
-        unset(PYTHON_LIBRARY)
-        find_library(PYTHON_LIBRARY
-            NAMES "python${PYTHON_LIBRARY_SUFFIX}"
-            PATHS ${_PYTHON_LIBS_SEARCH}
-            NO_DEFAULT_PATH)
+  # if we are in MSYS & MINGW, and we didn't find windows python lib, look for system python lib
+  if(DEFINED ENV{MSYSTEM}
+     AND MINGW
+     AND NOT EXISTS "${PYTHON_LIBRARY}")
+    if(PYTHON_MULTIARCH)
+      set(_PYTHON_LIBS_SEARCH "${PYTHON_LIBDIR}/${PYTHON_MULTIARCH}" "${PYTHON_LIBDIR}")
+    else()
+      set(_PYTHON_LIBS_SEARCH "${PYTHON_LIBDIR}")
     endif()
+    unset(PYTHON_LIBRARY)
+    find_library(
+      PYTHON_LIBRARY
+      NAMES "python${PYTHON_LIBRARY_SUFFIX}"
+      PATHS ${_PYTHON_LIBS_SEARCH}
+      NO_DEFAULT_PATH)
+  endif()
 
-    # raise an error if the python libs are still not found.
-    if(NOT EXISTS "${PYTHON_LIBRARY}")
-        message(FATAL_ERROR "Python libraries not found")
-    endif()
+  # raise an error if the python libs are still not found.
+  if(NOT EXISTS "${PYTHON_LIBRARY}")
+    message(FATAL_ERROR "Python libraries not found")
+  endif()
 
 else()
-    if(PYTHON_MULTIARCH)
-        set(_PYTHON_LIBS_SEARCH "${PYTHON_LIBDIR}/${PYTHON_MULTIARCH}" "${PYTHON_LIBDIR}")
-    else()
-        set(_PYTHON_LIBS_SEARCH "${PYTHON_LIBDIR}")
-    endif()
-    #message(STATUS "Searching for Python libs in ${_PYTHON_LIBS_SEARCH}")
-    # Probably this needs to be more involved. It would be nice if the config
-    # information the python interpreter itself gave us were more complete.
-    find_library(PYTHON_LIBRARY
-        NAMES "python${PYTHON_LIBRARY_SUFFIX}"
-        PATHS ${_PYTHON_LIBS_SEARCH}
-        NO_DEFAULT_PATH)
+  if(PYTHON_MULTIARCH)
+    set(_PYTHON_LIBS_SEARCH "${PYTHON_LIBDIR}/${PYTHON_MULTIARCH}" "${PYTHON_LIBDIR}")
+  else()
+    set(_PYTHON_LIBS_SEARCH "${PYTHON_LIBDIR}")
+  endif()
+  #message(STATUS "Searching for Python libs in ${_PYTHON_LIBS_SEARCH}")
+  # Probably this needs to be more involved. It would be nice if the config
+  # information the python interpreter itself gave us were more complete.
+  find_library(
+    PYTHON_LIBRARY
+    NAMES "python${PYTHON_LIBRARY_SUFFIX}"
+    PATHS ${_PYTHON_LIBS_SEARCH} NO_DEFAULT_PATH)
 
-    # If all else fails, just set the name/version and let the linker figure out the path.
-    if(NOT PYTHON_LIBRARY)
-        set(PYTHON_LIBRARY python${PYTHON_LIBRARY_SUFFIX})
-    endif()
+  # If all else fails, just set the name/version and let the linker figure out the path.
+  if(NOT PYTHON_LIBRARY)
+    set(PYTHON_LIBRARY python${PYTHON_LIBRARY_SUFFIX})
+  endif()
 endif()
 
-MARK_AS_ADVANCED(
-  PYTHON_LIBRARY
-  PYTHON_INCLUDE_DIR
-)
+mark_as_advanced(PYTHON_LIBRARY PYTHON_INCLUDE_DIR)
 
 # We use PYTHON_INCLUDE_DIR, PYTHON_LIBRARY and PYTHON_DEBUG_LIBRARY for the
 # cache entries because they are meant to specify the location of a single
 # library. We now set the variables listed by the documentation for this
 # module.
-SET(PYTHON_INCLUDE_DIRS "${PYTHON_INCLUDE_DIR}")
-SET(PYTHON_LIBRARIES "${PYTHON_LIBRARY}")
+set(PYTHON_INCLUDE_DIRS "${PYTHON_INCLUDE_DIR}")
+set(PYTHON_LIBRARIES "${PYTHON_LIBRARY}")
 if(NOT PYTHON_DEBUG_LIBRARY)
-    SET(PYTHON_DEBUG_LIBRARY "")
+  set(PYTHON_DEBUG_LIBRARY "")
 endif()
-SET(PYTHON_DEBUG_LIBRARIES "${PYTHON_DEBUG_LIBRARY}")
+set(PYTHON_DEBUG_LIBRARIES "${PYTHON_DEBUG_LIBRARY}")
 
-find_package_message(PYTHON
-    "Found PythonLibs: ${PYTHON_LIBRARY}"
-    "${PYTHON_EXECUTABLE}${PYTHON_VERSION_STRING}")
+find_package_message(PYTHON "Found PythonLibs: ${PYTHON_LIBRARY}"
+                     "${PYTHON_EXECUTABLE}${PYTHON_VERSION_STRING}")
 
 set(PYTHONLIBS_FOUND TRUE)
 set(PythonLibsNew_FOUND TRUE)
 
 if(NOT PYTHON_MODULE_PREFIX)
-    SET(PYTHON_MODULE_PREFIX "")
+  set(PYTHON_MODULE_PREFIX "")
 endif()
diff --git a/tools/pybind11Tools.cmake b/tools/pybind11Tools.cmake
index 742699aca..49876eb9f 100644
--- a/tools/pybind11Tools.cmake
+++ b/tools/pybind11Tools.cmake
@@ -10,18 +10,22 @@ cmake_minimum_required(VERSION 3.7)
 # VERSION 3.7...3.18, but some versions of VS have a patched CMake 3.11
 # that do not work properly with this syntax, so using the following workaround:
 if(${CMAKE_VERSION} VERSION_LESS 3.18)
-    cmake_policy(VERSION ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION})
+  cmake_policy(VERSION ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION})
 else()
-    cmake_policy(VERSION 3.18)
+  cmake_policy(VERSION 3.18)
 endif()
 
 # Add a CMake parameter for choosing a desired Python version
 if(NOT PYBIND11_PYTHON_VERSION)
-    set(PYBIND11_PYTHON_VERSION "" CACHE STRING "Python version to use for compiling modules")
+  set(PYBIND11_PYTHON_VERSION
+      ""
+      CACHE STRING "Python version to use for compiling modules")
 endif()
 
 # A user can set versions manually too
-set(Python_ADDITIONAL_VERSIONS "3.9;3.8;3.7;3.6;3.5;3.4" CACHE INTERNAL "")
+set(Python_ADDITIONAL_VERSIONS
+    "3.9;3.8;3.7;3.6;3.5;3.4"
+    CACHE INTERNAL "")
 find_package(PythonLibsNew ${PYBIND11_PYTHON_VERSION} REQUIRED)
 
 include(CheckCXXCompilerFlag)
@@ -29,76 +33,80 @@ include(CMakeParseArguments)
 
 # Warn or error if old variable name used
 if(PYBIND11_CPP_STANDARD)
-    if(NOT CMAKE_CXX_STANDARD)
-        string(REGEX MATCH
-            [=[..^]=]
-            VAL
-            "${PYBIND11_CPP_STANDARD}")
-        set(supported_standards 11 14 17 20)
-        if("${VAL}" IN_LIST supported_standards)
-            message(WARNING "USE -DCMAKE_CXX_STANDARD=${VAL} instead of PYBIND11_PYTHON_VERSION")
-            set(CMAKE_CXX_STANDARD ${VAL})
-        else()
-            message(FATAL_ERROR "PYBIND11_CPP_STANDARD should be replaced with CMAKE_CXX_STANDARD")
-        endif()
+  if(NOT CMAKE_CXX_STANDARD)
+    string(REGEX MATCH [=[..^]=] VAL "${PYBIND11_CPP_STANDARD}")
+    set(supported_standards 11 14 17 20)
+    if("${VAL}" IN_LIST supported_standards)
+      message(WARNING "USE -DCMAKE_CXX_STANDARD=${VAL} instead of PYBIND11_PYTHON_VERSION")
+      set(CMAKE_CXX_STANDARD ${VAL})
+    else()
+      message(FATAL_ERROR "PYBIND11_CPP_STANDARD should be replaced with CMAKE_CXX_STANDARD")
     endif()
+  endif()
 endif()
 
-
-
 # Checks whether the given CXX/linker flags can compile and link a cxx file.  cxxflags and
 # linkerflags are lists of flags to use.  The result variable is a unique variable name for each set
 # of flags: the compilation result will be cached base on the result variable.  If the flags work,
 # sets them in cxxflags_out/linkerflags_out internal cache variables (in addition to ${result}).
-function(_pybind11_return_if_cxx_and_linker_flags_work result cxxflags linkerflags cxxflags_out linkerflags_out)
+function(_pybind11_return_if_cxx_and_linker_flags_work result cxxflags linkerflags cxxflags_out
+         linkerflags_out)
   set(CMAKE_REQUIRED_LIBRARIES ${linkerflags})
   check_cxx_compiler_flag("${cxxflags}" ${result})
-  if (${result})
-    set(${cxxflags_out} "${cxxflags}" CACHE INTERNAL "" FORCE)
-    set(${linkerflags_out} "${linkerflags}" CACHE INTERNAL "" FORCE)
+  if(${result})
+    set(${cxxflags_out}
+        "${cxxflags}"
+        CACHE INTERNAL "" FORCE)
+    set(${linkerflags_out}
+        "${linkerflags}"
+        CACHE INTERNAL "" FORCE)
   endif()
 endfunction()
 
 # Internal: find the appropriate link time optimization flags for this compiler
 function(_pybind11_add_lto_flags target_name prefer_thin_lto)
-  if (NOT DEFINED PYBIND11_LTO_CXX_FLAGS)
-    set(PYBIND11_LTO_CXX_FLAGS "" CACHE INTERNAL "")
-    set(PYBIND11_LTO_LINKER_FLAGS "" CACHE INTERNAL "")
+  if(NOT DEFINED PYBIND11_LTO_CXX_FLAGS)
+    set(PYBIND11_LTO_CXX_FLAGS
+        ""
+        CACHE INTERNAL "")
+    set(PYBIND11_LTO_LINKER_FLAGS
+        ""
+        CACHE INTERNAL "")
 
     if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
       set(cxx_append "")
       set(linker_append "")
-      if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND NOT APPLE)
+      if(CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND NOT APPLE)
         # Clang Gold plugin does not support -Os; append -O3 to MinSizeRel builds to override it
         set(linker_append ";$<$<CONFIG:MinSizeRel>:-O3>")
       elseif(CMAKE_CXX_COMPILER_ID MATCHES "GNU")
         set(cxx_append ";-fno-fat-lto-objects")
       endif()
 
-      if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND prefer_thin_lto)
-        _pybind11_return_if_cxx_and_linker_flags_work(HAS_FLTO_THIN
-          "-flto=thin${cxx_append}" "-flto=thin${linker_append}"
+      if(CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND prefer_thin_lto)
+        _pybind11_return_if_cxx_and_linker_flags_work(
+          HAS_FLTO_THIN "-flto=thin${cxx_append}" "-flto=thin${linker_append}"
           PYBIND11_LTO_CXX_FLAGS PYBIND11_LTO_LINKER_FLAGS)
       endif()
 
-      if (NOT HAS_FLTO_THIN)
-        _pybind11_return_if_cxx_and_linker_flags_work(HAS_FLTO
-          "-flto${cxx_append}" "-flto${linker_append}"
-          PYBIND11_LTO_CXX_FLAGS PYBIND11_LTO_LINKER_FLAGS)
+      if(NOT HAS_FLTO_THIN)
+        _pybind11_return_if_cxx_and_linker_flags_work(
+          HAS_FLTO "-flto${cxx_append}" "-flto${linker_append}" PYBIND11_LTO_CXX_FLAGS
+          PYBIND11_LTO_LINKER_FLAGS)
       endif()
-    elseif (CMAKE_CXX_COMPILER_ID MATCHES "Intel")
+    elseif(CMAKE_CXX_COMPILER_ID MATCHES "Intel")
       # Intel equivalent to LTO is called IPO
-      _pybind11_return_if_cxx_and_linker_flags_work(HAS_INTEL_IPO
-      "-ipo" "-ipo" PYBIND11_LTO_CXX_FLAGS PYBIND11_LTO_LINKER_FLAGS)
+      _pybind11_return_if_cxx_and_linker_flags_work(
+        HAS_INTEL_IPO "-ipo" "-ipo" PYBIND11_LTO_CXX_FLAGS PYBIND11_LTO_LINKER_FLAGS)
     elseif(MSVC)
       # cmake only interprets libraries as linker flags when they start with a - (otherwise it
       # converts /LTCG to \LTCG as if it was a Windows path).  Luckily MSVC supports passing flags
       # with - instead of /, even if it is a bit non-standard:
-      _pybind11_return_if_cxx_and_linker_flags_work(HAS_MSVC_GL_LTCG
-        "/GL" "-LTCG" PYBIND11_LTO_CXX_FLAGS PYBIND11_LTO_LINKER_FLAGS)
+      _pybind11_return_if_cxx_and_linker_flags_work(
+        HAS_MSVC_GL_LTCG "/GL" "-LTCG" PYBIND11_LTO_CXX_FLAGS PYBIND11_LTO_LINKER_FLAGS)
     endif()
 
-    if (PYBIND11_LTO_CXX_FLAGS)
+    if(PYBIND11_LTO_CXX_FLAGS)
       message(STATUS "LTO enabled")
     else()
       message(STATUS "LTO disabled (not supported by the compiler and/or linker)")
@@ -106,12 +114,13 @@ function(_pybind11_add_lto_flags target_name prefer_thin_lto)
   endif()
 
   # Enable LTO flags if found, except for Debug builds
-  if (PYBIND11_LTO_CXX_FLAGS)
+  if(PYBIND11_LTO_CXX_FLAGS)
     set(not_debug "$<NOT:$<CONFIG:Debug>>")
     set(cxx_lang "$<COMPILE_LANGUAGE:CXX>")
-    target_compile_options(${target_name} PRIVATE "$<$<AND:${not_debug},${cxx_lang}>:${PYBIND11_LTO_CXX_FLAGS}>")
+    target_compile_options(${target_name}
+                           PRIVATE "$<$<AND:${not_debug},${cxx_lang}>:${PYBIND11_LTO_CXX_FLAGS}>")
   endif()
-  if (PYBIND11_LTO_LINKER_FLAGS)
+  if(PYBIND11_LTO_LINKER_FLAGS)
     target_link_libraries(${target_name} PRIVATE "$<${not_debug}:${PYBIND11_LTO_LINKER_FLAGS}>")
   endif()
 endfunction()
@@ -143,7 +152,10 @@ function(pybind11_add_module target_name)
   target_link_libraries(${target_name} PRIVATE pybind11::module)
 
   if(ARG_SYSTEM)
-      message(STATUS "Warning: this does not have an effect - use NO_SYSTEM_FROM_IMPORTED if using imported targets")
+    message(
+      STATUS
+        "Warning: this does not have an effect - use NO_SYSTEM_FROM_IMPORTED if using imported targets"
+    )
   endif()
 
   # Python debug libraries expose slightly different objects before 3.8
@@ -165,35 +177,33 @@ function(pybind11_add_module target_name)
   set_target_properties(${target_name} PROPERTIES CXX_VISIBILITY_PRESET "hidden")
   set_target_properties(${target_name} PROPERTIES CUDA_VISIBILITY_PRESET "hidden")
 
-
   if(ARG_NO_EXTRAS)
-      return()
+    return()
   endif()
 
   if(CMAKE_VERSION VERSION_LESS 3.9 OR PYBIND11_CLASSIC_LTO)
-      _pybind11_add_lto_flags(${target_name} ${ARG_THIN_LTO})
+    _pybind11_add_lto_flags(${target_name} ${ARG_THIN_LTO})
   else()
-      include(CheckIPOSupported)
-      check_ipo_supported(RESULT supported OUTPUT error)
-      if(supported)
-          set_property(
-            TARGET
-              ${target_name}
-            PROPERTY
-              INTERPROCEDURAL_OPTIMIZATION TRUE
-            )
-      endif()
+    include(CheckIPOSupported)
+    check_ipo_supported(RESULT supported OUTPUT error)
+    if(supported)
+      set_property(TARGET ${target_name} PROPERTY INTERPROCEDURAL_OPTIMIZATION TRUE)
+    endif()
   endif()
 
-  if (NOT MSVC AND NOT ${CMAKE_BUILD_TYPE} MATCHES Debug|RelWithDebInfo)
+  if(NOT MSVC AND NOT ${CMAKE_BUILD_TYPE} MATCHES Debug|RelWithDebInfo)
     # Strip unnecessary sections of the binary on Linux/Mac OS
     if(CMAKE_STRIP)
       if(APPLE)
-        add_custom_command(TARGET ${target_name} POST_BUILD
-                           COMMAND ${CMAKE_STRIP} -x $<TARGET_FILE:${target_name}>)
+        add_custom_command(
+          TARGET ${target_name}
+          POST_BUILD
+          COMMAND ${CMAKE_STRIP} -x $<TARGET_FILE:${target_name}>)
       else()
-        add_custom_command(TARGET ${target_name} POST_BUILD
-                           COMMAND ${CMAKE_STRIP} $<TARGET_FILE:${target_name}>)
+        add_custom_command(
+          TARGET ${target_name}
+          POST_BUILD
+          COMMAND ${CMAKE_STRIP} $<TARGET_FILE:${target_name}>)
       endif()
     endif()
   endif()
@@ -209,7 +219,8 @@ function(pybind11_add_module target_name)
       # instance, projects that include other types of source files like CUDA
       # .cu files don't get these options propagated to nvcc since that would
       # cause the build to fail.
-      target_compile_options(${target_name} PRIVATE $<$<NOT:$<CONFIG:Debug>>:$<$<COMPILE_LANGUAGE:CXX>:/MP>>)
+      target_compile_options(${target_name}
+                             PRIVATE $<$<NOT:$<CONFIG:Debug>>:$<$<COMPILE_LANGUAGE:CXX>:/MP>>)
     endif()
   endif()
 endfunction()