Convert two vectors of int with the same length into one vector of pairs of int in C++

Question

In C++, if I have two vectors of int:

A = [1, 2, 3 ,4]; 
B = [1, 2, 3, 4]; 

How can I merge them into one vector of pairs:

[(1,1), (2,2), (3,3), (4, 4)]

Of course I can do that with a loop. But can we do that using suitable STL functions and iterators?

Answer 1

You can use an algorithm for this:

std::vector<std::pair<int, int>> target;
target.reserve(A.size());
std::transform(A.begin(), A.end(), B.begin(), std::back_inserter(target),
               [](int a, int b) { return std::make_pair(a, b); });