Concatenating two std::vectors

Question

How do I concatenate two std::vectors?

Answer 1

A general performance boost for concatenate is to check the size of the vectors. And merge/insert the smaller one with the larger one.

//vector v1,v2;
if(v1.size()>v2.size()) {
    v1.insert(v1.end(),v2.begin(),v2.end());
} else {
    v2.insert(v2.end(),v1.begin(),v1.end());
}