count_if()

template<typename _InputIterator, typename _Predicate, typename _Size>

void __gnu_cxx::count_if	(	_InputIterator	__first,
		_InputIterator	__last,
		_Predicate	__pred,
		_Size &	__n )

Definition at line 239 of file ext/algorithm.

    {
      // concept requirements
      __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
      __glibcxx_function_requires(_UnaryPredicateConcept<_Predicate,
          typename std::iterator_traits<_InputIterator>::value_type>)
      __glibcxx_requires_valid_range(__first, __last);
 
      for ( ; __first != __last; ++__first)
      if (__pred(*__first))
        ++__n;
    }

References __glibcxx_function_requires, and __glibcxx_requires_valid_range.