I'm aware that "arm-none-eabi" toolchain is a set to toolchains to be used with baremetal environment (aka freestanding). With C++ Standard Template Library I'm trying to figure out which parts of it are supported by this toolchain. I have recently found out that multithreading support isn't included. However when <atomic> library is used, project files do get compiled and built. So, am I actually "allowed" to used atomics with STL or not, since C++ considers <atomic> library a part of the "Concurrency support library"?