boost/mpl/count_if.hpp
//-----------------------------------------------------------------------------
// boost mpl/count_if.hpp header file
// See http://www.boost.org for updates, documentation, and revision history.
//-----------------------------------------------------------------------------
//
// Copyright (c) 2000-02
// Aleksey Gurtovoy
//
// Permission to use, copy, modify, distribute and sell this software
// and its documentation for any purpose is hereby granted without fee,
// provided that the above copyright notice appears in all copies and
// that both the copyright notice and this permission notice appear in
// supporting documentation. No representations are made about the
// suitability of this software for any purpose. It is provided "as is"
// without express or implied warranty.
#ifndef BOOST_MPL_COUNT_IF_HPP_INCLUDED
#define BOOST_MPL_COUNT_IF_HPP_INCLUDED
#include "boost/mpl/fold.hpp"
#include "boost/mpl/next.hpp"
#include "boost/mpl/integral_c.hpp"
#include "boost/mpl/identity.hpp"
#include "boost/mpl/apply_if.hpp"
#include "boost/mpl/lambda.hpp"
#include "boost/mpl/protect.hpp"
#include "boost/mpl/apply.hpp"
#include "boost/mpl/aux_/void_spec.hpp"
#include "boost/mpl/aux_/lambda_support.hpp"
namespace boost {
namespace mpl {
namespace aux {
template< typename Predicate >
struct next_if
{
template<
typename N
, typename T
>
struct apply
{
typedef typename apply_if<
typename apply1<Predicate,T>::type
, next<N>
, identity<N>
>::type type;
};
};
} // namespace aux
BOOST_MPL_AUX_AGLORITHM_NAMESPACE_BEGIN
template<
typename BOOST_MPL_AUX_VOID_SPEC_PARAM(Sequence)
, typename BOOST_MPL_AUX_VOID_SPEC_PARAM(Predicate)
>
struct count_if
{
private:
typedef typename lambda<Predicate>::type pred_;
public:
typedef typename fold<
Sequence
, integral_c<unsigned long, 0>
, protect< aux::next_if<pred_> >
>::type type;
BOOST_MPL_AUX_LAMBDA_SUPPORT(2,count_if,(Sequence,Predicate))
};
BOOST_MPL_AUX_AGLORITHM_NAMESPACE_END
BOOST_MPL_AUX_ALGORITHM_VOID_SPEC(2, count_if)
} // namespace mpl
} // namespace boost
#endif // BOOST_MPL_COUNT_IF_HPP_INCLUDED