count

template<
      typename Sequence
    , typename T
    >
struct count
{
    typedef unspecified type;
};

Returns the number of elements in a Sequence that are identical to T.

#include <boost/mpl/count.hpp>

Parameter	Requirement	Description
`Sequence`	Forward Sequence	A sequence to be examined.
`T`	Any type	A type to search for.

For any Forward Sequence s and arbitrary type t:

typedef count<s,t>::type n;

Return type:

Return type:	Integral Constant.
Semantics:	Equivalent to typedef count_if< s,is_same<_,T> >::type n;

Semantics:

Equivalent to

typedef count_if< s,is_same<_,T> >::type n;

Linear. Exactly size<s>::value comparisons for identity.

typedef vector<int,char,long,short,char,short,double,long> types;
typedef count<types, short>::type n;

BOOST_MPL_ASSERT_RELATION( n::value, ==, 2 );