noexcept is also important for optimization. If a template function is guaranteed to be exception-safe, and it’s called with a type whose move constructor isn’

noexcept is also important for optimization. If a template function is guaranteed to be exception-safe, and it’s called with a type whose move constructor isn’t noexcept, then the function needs to fallback to the copy constructor to maintain exception-safety. This happens a lot with the standard library.