If you check the C++ standard you will find that std::hash is a struct instead of a function. Reference is here. It has the () operator overloaded so … ...more

Perfect forwarding comes from std::forward() is one of the special C++ technique to reduce the code length. More information can be found on cpprefere… ...more

Virtual function is the core feature of C++, it was introduced to C++ from the very beginning. It gives C++ something that C does not have, which is k… ...more