function-args-by-value

Warns when you should be passing by value instead of by-ref. Types with sizeof <= 16 bytes [1] which are trivially-copyable [2] and trivially-destructible [3] should be passed by value.

Only fix these warnings if you're sure that the value would be passed in a CPU register instead on the stack.

• [1] http://www.macieira.org/blog/2012/02/the-value-of-passing-by-value/
• [2] http://en.cppreference.com/w/cpp/concept/TriviallyCopyable
• [3] http://www.cplusplus.com/reference/type_traits/is_trivially_destructible/