c++ - A way to use the STL to count chars in a vector of std::string? -

so while it's trivial find amount of characters inside of vector of std::string, wondering if there's way use stl of work instead of having 2 loops, 1 loop through vector , loop through string in each index of vector.

i've tried using other stl functions (such attempting use std::for_each in few unique ways), of attempts have resulted in no success.

int main(void) {   int chars = 0;   std::vector<std::string> str;   str.push_back("vector");   str.push_back("of");   str.push_back("four");   str.push_back("words");    for(int = 0; < str.size(); ++i)     for(int j = 0; j < str[i].size(); ++j)       ++chars;    std::cout << "number of characters: " << chars; // 17 characters    // there stl methods allows me find 'chars'   // without needing write multiple loops?  } 

to start, not need second loop:

for(int = 0; < str.size(); ++i) {     chars += str[i].size(); } 

now standard library solution:

int chars = accumulate(str.begin(), str.end(), 0, [](int sum, const string& elem) {     return sum + elem.size(); }); 

here demo on ideone.