uppercasing vector of strings using iterators

vec_str_upp_it.cpp

#include <iostream>
#include <string>
#include <vector>

int main()
{
    std::vector<std::string> vec_str = {"helllllllllllllo"};

    for(auto it = vec_str.begin(); it != vec_str.end(); ++it) {
        for(auto &c : *it)
        c = toupper(c);
    }

    for(std::vector<std::string>::iterator it1 = vec_str.begin(); it1 != vec_str.end(); ++it1)
        std::cout << *it1 << std::endl;


    return 0;
}