Using Requires in C++ 20

C++ 20 features are becoming more available to people who are switching to new and compilers. Tristan Brindall raises an interesting point about using concepts in places where Sine can't like on destructors and copy move constructors. This is useful for things like Stad optional, whose special members should be trivial whenever the equivalent operation on T is trivial. You can also use requires in constexpr if this is a function that can return the number of elements in a container or a custom class.