Using <filesystem> on macOS 10.13 with clang++-mp-13

[Mojca Miklavec]

Hi,

I'm trying to build some sources that require <filesystem> on 10.13
using clang 13 (I can try with clang 14, but I doubt that it helps).

What's the correct way to compile the following minimal example? Do I
need to link against a newer libc++ somehow?

If it's not feasible to do that, I'll target a newer OS, I was just
silently hoping to have some success ;)

Thank you,
    Mojca

#include <cstdlib>
#include <filesystem>

int main() {
    auto cwd = std::filesystem::current_path();
    printf("%s", cwd.c_str());
    return EXIT_SUCCESS;
}

> clang++-mp-13 test.cpp -o test
test.cpp:5:16: error: no member named 'filesystem' in namespace 'std';
did you mean 'std::__fs::filesystem'?
    auto cwd = std::filesystem::current_path();
               ^~~~~~~~~~~~~~~
               std::__fs::filesystem
/opt/local/libexec/llvm-13/bin/../include/c++/v1/filesystem:268:1:
note: 'std::__fs::filesystem' declared here
_LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
^
/opt/local/libexec/llvm-13/bin/../include/c++/v1/__config:816:58:
note: expanded from macro '_LIBCPP_BEGIN_NAMESPACE_FILESYSTEM'
  _LIBCPP_BEGIN_NAMESPACE_STD namespace __fs { namespace filesystem {
                                                         ^
1 error generated.

> clang++-mp-13 -std=c++17 test.cpp -o test
Undefined symbols for architecture x86_64:
  "std::__1::__fs::filesystem::__current_path(std::__1::error_code*)",
referenced from:
      std::__1::__fs::filesystem::current_path() in test-1b2bbf.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)