Can not build on Ubuntu 18.04 with Clang #152
Description
When using Clang on an older Linux like Ubuntu 18.04 (gcc-7), the build should link to stdc++fs unless skyr_BUILD_WITH_LLVM_LIBCXX is given.
I've tested that it works when using something like:
set(clang_with_gnu_stdlib $<AND:$<CXX_COMPILER_ID:Clang>,$<NOT:$<BOOL:${WIN32}>>,$<NOT:$<BOOL:${skyr_BUILD_WITH_LLVM_LIBCXX}>>>)
[...]
target_link_libraries(
skyr-filesystem
[...]
$<${clang_with_gnu_stdlib}:"stdc++fs">