count_if()

template<typename Pred , product_type T>

constexpr std::size_t kumi::count_if ( T &&  ts, Pred  p  )

inlineconstexprnoexcept

Counts the number of elements of t satisfying predicates p.

Parameters

ts	Value to process
p	Unary predicate. p must return a value convertible to bool for every element of t.

Returns

Number of elements satisfying the condition.

Example:

 
#include <kumi/kumi.hpp>
#include <iostream>
#include <type_traits>
 
int main()
{
  auto t = kumi::tuple{1, 2., 3.f, 'z'};
  std::cout << std::boolalpha
            << kumi::count_if( t, kumi::predicate<std::is_floating_point>() ) << "\n";
}