C++ parameter passing rules

From: https://www.modernescpp.com/index.php/c-core-guidelines-how-to-pass-function-parameters

Parameter passing expression rules:

• F.15: Prefer simple and conventional ways of passing information
• F.16: For “in” parameters, pass cheaply-copied types by value and others by reference to const
• F.17: For “in-out” parameters, pass by reference to non-const
• F.18: For “consume” parameters, pass by X&& and std::move the parameter
• F.19: For “forward” parameters, pass by TP&& and only std::forward the parameter
• F.20: For “out” output values, prefer return values to output parameters
• F.21: To return multiple “out” values, prefer returning a tuple or struct
• F.60: Prefer T* over T& when “no argument” is a valid option