Caleth questions

Caleth answers

• Why can't I use `using` in a multiple inheritance c++?
• xvalues vs prvalues: what does identity property add
• How do I use multiple overloads to get different answers based on the amount of numbers passed in?
• Template: How to select smallest int type which holds n bits?
• How do you define a C++ concept for the standard library containers?
• Why do unique_ptr have two functions reset and operator= that do similar things but not overload?
• How to create an STL output iterator for a Eigen matrix?
• Can c++ std::source_location be used with a conversion operator?
• Dereference wrapper for vector of unique_ptr?
• The deduction guide for std::array