In my understanding, with this specific feature, if you want a polyfill for older compilers, or to use some more cutting-edge features that haven't been standardized yet, https://github.com/fmtlib/fmt is available to you.
gcc 14 has not yet been released; going by past years, 14.1 should come out around the start of May (2024). clang 17 was released September (2023); note that you need to use libc++ (stlib=libc++), not libstdc++. VS 2022 17.7 has been out since August.
std::println is, yes.
> I wonder how available this is within compilers
https://en.cppreference.com/w/cpp/compiler_support says clang, gcc, and msvc all support it, though I don't know how recent those versions are off the top of my head.
In my understanding, with this specific feature, if you want a polyfill for older compilers, or to use some more cutting-edge features that haven't been standardized yet, https://github.com/fmtlib/fmt is available to you.