It's an implementation issue that matters if you're writing a system that needs to offer high performance today. Regarding writing assembly - that's fine, you

It's an implementation issue that matters if you're writing a system that needs to offer high performance today. Regarding writing assembly - that's fine, you could also write a routine in C and call it. The thrust of my comment is that it is untrue to argue that native Go and Java match the performance of C/C++. They don't. They might in the future.