cmake HAVE_LIBCXX examples

Lewuathe/mlir-hello thirdparty/llvm-project/compiler-rt/lib/fuzzer/CMakeLists.txt :67 

elseif(TARGET cxx-headers OR HAVE_LIBCXX)

pingcap/tiflash CMakeLists.txt :212 

option (USE_LIBCXX "Use libc++ and libc++abi instead of libstdc++ (only make sense on Linux with Clang)" ${HAVE_LIBCXX})

pingcap/tiflash cmake/test_compiler.cmake :31 

check_cxx_source_compiles("
    #include <iostream>
    int main() {
        std::cerr << std::endl;
        return 0;
    }
    " HAVE_LIBCXX)

kcat/openal-soft CMakeLists.txt :162 

check_cxx_symbol_exists(_LIBCPP_VERSION "version" HAVE_LIBCXX)

kcat/openal-soft CMakeLists.txt :182 

elseif(HAVE_LIBCXX)

CTSRD-CHERI/cheribsd contrib/subrepo-cheri-compiler-rt/lib/fuzzer/CMakeLists.txt :67 

elseif(TARGET cxx-headers OR HAVE_LIBCXX)