contains

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

Returns a true-valued Integral Constant if one or more elements in Sequence are identical to T.

#include <boost/mpl/contains.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 contains<s,t>::type r;

Return type: Integral Constant.

Semantics:

Return type:	Integral Constant.
Semantics:	Equivalent to typedef not_< is_same< find<s,t>::type , end<s>::type > >::type r;

Equivalent to

typedef not_< is_same< 
      find<s,t>::type
    , end<s>::type
    > >::type r;

Linear. At most size<s>::value comparisons for identity.

typedef vector<char,int,unsigned,long,unsigned long> types;
BOOST_MPL_ASSERT_NOT(( contains<types,bool> ));