About a month ago, I got an interesting pull request for lexy, my new parser combinator library. It fixed a seemingly weird issue relating trivially copyable types and special member function of classes containing unions. While digging into it, I learned a lot about trivial special member functions and made a somewhat surprising realization: Just because a class is std::is_trivially_copyable does not mean the class is actually std::is_trivially_copy_constructible or even std::is_copy_construc...
