Sorting a std::vector> by the string?

Question

How can I sort this vector by comparing the pair.first which is an std::string? (without providing a static compare function, nor use

Answer 1

std::vector > v;
std::sort(v.begin(), v.end());

std::pair overloads operator< to sort first by the first element then by the second element. Thus, if you just sort the vector using the default sort ordering (operator<), you'll get your desired ordering.