@vaporeon_ @aescling decltype eats an expression and the result is the type of that expression.

This is what it's usage looks like. (This a silly thing to do, of course. But I wanted a simple demonstration of the syntax)

int a = 3;
decltype(a) c = a;

Apparently there are situations where manually writing the type of something is really really nasty and just saying "look C++, it's whatever the type of this thing is" can be convenient

@wallhackio @vaporeon_ at that point you might as well use auto instead

@aescling @vaporeon_ auto does not treat references types the way you might expect: https://stackoverflow.com/a/12084107