...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
A metafunction that returns the result type of count_if given the sequence and predicate types.
template< typename Sequence, typename Pred > struct count_if { typedef int type; };
Table 1.52. Parameters
Parameter |
Requirement |
Description |
---|---|---|
Sequence |
A model of Forward Sequence |
Operation's argument |
Pred |
A unary function object |
Operation's argument |
result_of::count_if<Sequence, Pred>::type
Return type: int.
Semantics: Returns the return type of count_if. The return type is always int.
Constant.
#include <boost/fusion/algorithm/query/count_if.hpp> #include <boost/fusion/include/count_if.hpp>