Caleth questions

Caleth answers

• Is dereferencing std::span::end always undefined?
• C++ template specialization with types which have certain interface
• Is there a widely used "tag" base class for C++ static classes?
• When to use std::make_shared_for_overwrite?
• Which value category does x have in `((struct s*)0)->x?
• `std::remove` in template function causing problems with `vector.begin()` being `const`
• Is there any standard functionality for creating a flattened view of a map with a container as the mapped_type?
• Questions about std::lower_bound and std::upper_bound
• How to create c++ assignment operator for =0
• How to set member variables of class inside class without setter?