Why std::filesystem is not supported On Mac qt6.2

[isudfv]

QFile has a public function std::filesystem::path filesystemFileName() const but it doesn't work on Mac, because #define QT_FEATURE_cxx17_filesystem is set to -1 in qtcore-config.h. Why is this?

[J.Hilk]

@isudfv

for the longest time, clang only supported C++17 language features but not C++17 standard library features, with std::filesystem being a library feature.

I think, you'll need at least clang 9 or 10.

So what are you using, what was used for the qt libs to compile ? thats where the config.h comes from (I think)

[isudfv]

@J-Hilk I'm using Apple clang version 13.1.6 (clang-1316.0.21.2.3) and Qt 6.2.4 macos. std::filesystem is available as long as I set CMAKE_CXX_STANDARD to 17 or later

[J.Hilk]

@isudfv
mmh, very odd, Qt6.2 does, afaik, require c++17 support, so, that define should be available 🤔

[SGaist]

Hi,

Did you build Qt yourself ?
If not, how did you install it ?