cmake HAVE_STD_FILESYSTEM examples

ROCm/rocFFT cmake/std-filesystem.cmake :34 

check_cxx_source_compiles("${HAVE_STD_FILESYSTEM_TEST}" HAVE_STD_FILESYSTEM)

MRPT/mrpt cmakemodules/FindFilesystem.cmake :26 

check_include_file_cxx("filesystem" HAVE_STD_FILESYSTEM)

MRPT/mrpt cmakemodules/FindFilesystem.cmake :60 

target_compile_definitions(CXX::Filesystem INTERFACE STD_FS_IS_EXPERIMENTAL=$<NOT:$<BOOL:${HAVE_STD_FILESYSTEM}>>)

MRPT/mrpt cmakemodules/FindFilesystem.cmake :62 

set_property(TARGET CXX::Filesystem APPEND PROPERTY INTERFACE_COMPILE_DEFINITIONS STD_FS_IS_EXPERIMENTAL=$<NOT:$<BOOL:${HAVE_STD_FILESYSTEM}>>)

libgeos/geos tests/unit/CMakeLists.txt :29 

try_compile(HAVE_STD_FILESYSTEM "${CMAKE_BINARY_DIR}/temp" "${_filename}")

libgeos/geos tests/unit/CMakeLists.txt :37 

target_compile_definitions(test_geos_unit PRIVATE HAVE_STD_FILESYSTEM)

libgeos/geos tests/unit/CMakeLists.txt :43 

target_compile_definitions(test_geos_unit PRIVATE HAVE_STD_FILESYSTEM=0)