[coffeeaddict1]

They're only supported in MSVC and GCC (for the latter you need to link against Intel's TBB to make it work). Support in libc++ (Clang) is work in progress.

[pca006132]

Clang does support parallel stl already (requires either TBB or OpenMP). Our project https://github.com/elalish/manifold made use of this to speed up mesh processing algorithms a lot.

[coffeeaddict1]

Does it? You mean if you link against libstdc++ instead of libc++?

[pca006132]

I remember it works for libc++ (partially, see https://libcxx.llvm.org/Status/PSTL.html), but forgot when I linked against libc++ last time...