(C++) std::count_if

 

std::count_if is an STL algorithm for counting elements in a container matching a certain predicate. For counting without a predicate use std::count.

 

 

 

 

 

Example: CountNonZeroes

 

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#include <algorithm> #include <vector> //From http://www.richelbilderbeek.nl/CppCountNonZeroes.htm int CountNonZeroes(const std::vector<double>& v) {  return std::count_if(     v.begin(),     v.end(),     std::bind2nd(std::not_equal_to<double>(),0.0)); }