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

Answer to "duplicate question" of this: link: Sort a vector of pairs by first element then by second element of the pair in C++?

bool cmp(const pair&x,const pairy){
if(x.first==y.first){
   return(x.second