How to use vector::push_back()` with a struct?

point mypoint = {0, 1};
a.push_back(mypoint);

Or if you’re allowed, give point a constructor, so that you can use a temporary:

a.push_back(point(0,1));

Some people will object if you put a constructor in a class declared with struct, and it makes it non-POD, and maybe you aren’t in control of the definition of point. So this option might not be available to you. However, you can write a function which provides the same convenience:

point make_point(int x, int y) {
    point mypoint = {x, y};
    return mypoint;
}

a.push_back(make_point(0, 1));