Creating pair object c++

Question

Why it's not possible to create a pair object in the following way:

pair<int,int> p1 = {0,42}

Answer 1

in C++03 you should use

std::make_pair(0, 42);

since pair is not simple data-structure. or by calling constructor of pair i.e.

std::pair<int, int> p1(0, 42);

in C++11

pair<int, int> p1 = {0, 42}

is okay.