Python cryptography, Rust, and Gentoo

Actually, this is relevant to the discussion. A Rust mutex isn't standalone but a container, and it must be able to guarantee that its contents are a valid value for the contained type, whereas a C++ std::mutex doesn't have any knowledge of the data it protects. The former approach makes it possible to guarantee protected access, but it makes the mutex implementation that much difficult.

I agree that it's a bit of a shame to have to resort to a thirdparty crate to easily have a global mutex-protected variable, but as pointed by someone else in the thread, it turns out the approach used by the proeminent crate for this might not be the best after all, which makes me glad it has not been imported into std after all :)