blame: source/misc/embedded_libs/fmt-8.1.1/support/cmake/cxx14.cmake

# C++14 feature support detection

include(CheckCXXSourceCompiles)

include(CheckCXXCompilerFlag)

if (NOT CMAKE_CXX_STANDARD)

  set(CMAKE_CXX_STANDARD 11)

endif()

message(STATUS "CXX_STANDARD: ${CMAKE_CXX_STANDARD}")

if (CMAKE_CXX_STANDARD EQUAL 20)

  check_cxx_compiler_flag(-std=c++20 has_std_20_flag)

  check_cxx_compiler_flag(-std=c++2a has_std_2a_flag)

  if (has_std_20_flag)

    set(CXX_STANDARD_FLAG -std=c++20)

  elseif (has_std_2a_flag)

    set(CXX_STANDARD_FLAG -std=c++2a)

  endif ()

elseif (CMAKE_CXX_STANDARD EQUAL 17)

  check_cxx_compiler_flag(-std=c++17 has_std_17_flag)

  check_cxx_compiler_flag(-std=c++1z has_std_1z_flag)

  if (has_std_17_flag)

    set(CXX_STANDARD_FLAG -std=c++17)

  elseif (has_std_1z_flag)

    set(CXX_STANDARD_FLAG -std=c++1z)

  endif ()

elseif (CMAKE_CXX_STANDARD EQUAL 14)

  check_cxx_compiler_flag(-std=c++14 has_std_14_flag)

  check_cxx_compiler_flag(-std=c++1y has_std_1y_flag)

  if (has_std_14_flag)

    set(CXX_STANDARD_FLAG -std=c++14)

  elseif (has_std_1y_flag)

    set(CXX_STANDARD_FLAG -std=c++1y)

  endif ()

elseif (CMAKE_CXX_STANDARD EQUAL 11)

  check_cxx_compiler_flag(-std=c++11 has_std_11_flag)

  check_cxx_compiler_flag(-std=c++0x has_std_0x_flag)

  if (has_std_11_flag)

    set(CXX_STANDARD_FLAG -std=c++11)

  elseif (has_std_0x_flag)

    set(CXX_STANDARD_FLAG -std=c++0x)

  endif ()

endif ()

set(CMAKE_REQUIRED_FLAGS ${CXX_STANDARD_FLAG})

# Check if user-defined literals are available

check_cxx_source_compiles("

  void operator\"\" _udl(long double);

  int main() {}"

  SUPPORTS_USER_DEFINED_LITERALS)

if (NOT SUPPORTS_USER_DEFINED_LITERALS)

  set (SUPPORTS_USER_DEFINED_LITERALS OFF)

endif ()

# Check if <variant> is available

set(CMAKE_REQUIRED_FLAGS -std=c++1z)

check_cxx_source_compiles("

  #include <variant>

  int main() {}"

  FMT_HAS_VARIANT)

if (NOT FMT_HAS_VARIANT)

  set (FMT_HAS_VARIANT OFF)

endif ()

set(CMAKE_REQUIRED_FLAGS )