C++17: Logical operator traits

C++17 added the type traits: conjunction, disjunction, and negation.

References:

https://en.wikipedia.org/wiki/C%2B%2B17

http://en.cppreference.com/w/cpp/types/conjunction

http://en.cppreference.com/w/cpp/types/disjunction

http://en.cppreference.com/w/cpp/types/negation