Why ={} initialization doesn't work for tuple?

Question

To me a pair is just special case of a tuple, but following surprises me:

pair p1(1, 2);   // ok
tuple

        

Answer 1

The tuple constructor you're trying to call is explicit, so copy-list-initialization will fail. The corresponding pair constructor is not explicit.

Change your code to

tuple t2{1, 2};

and it'll compile.