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// -- Boost Lambda Library -------------------------------------------------
// Copyright (C) 1999, 2000 Jaakko Jarvi (jaakko.jarvi@cs.utu.fi)
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// For more information, see www.boost.org
// --------------------------------------------------
#ifndef NDNBOOST_LAMBDA_ARITY_CODE_HPP
#define NDNBOOST_LAMBDA_ARITY_CODE_HPP
#include "ndnboost/type_traits/cv_traits.hpp"
#include "ndnboost/type_traits/transform_traits.hpp"
namespace ndnboost {
namespace lambda {
// These constants state, whether a lambda_functor instantiation results from
// an expression which contains no placeholders (NONE),
// only free1 placeholders (FIRST),
// free2 placeholders and maybe free1 placeholders (SECOND),
// free3 and maybe free1 and free2 placeholders (THIRD),
// freeE placeholders and maybe free1 and free2 (EXCEPTION).
// RETHROW means, that a rethrow expression is used somewhere in the lambda_functor.
enum { NONE = 0x00, // Notice we are using bits as flags here.
FIRST = 0x01,
SECOND = 0x02,
THIRD = 0x04,
EXCEPTION = 0x08,
RETHROW = 0x10};
template<class T>
struct get_tuple_arity;
namespace detail {
template <class T> struct get_arity_;
} // end detail;
template <class T> struct get_arity {
NDNBOOST_STATIC_CONSTANT(int, value = detail::get_arity_<typename ndnboost::remove_cv<typename ndnboost::remove_reference<T>::type>::type>::value);
};
namespace detail {
template<class T>
struct get_arity_ {
NDNBOOST_STATIC_CONSTANT(int, value = 0);
};
template<class T>
struct get_arity_<lambda_functor<T> > {
NDNBOOST_STATIC_CONSTANT(int, value = get_arity<T>::value);
};
template<class Action, class Args>
struct get_arity_<lambda_functor_base<Action, Args> > {
NDNBOOST_STATIC_CONSTANT(int, value = get_tuple_arity<Args>::value);
};
template<int I>
struct get_arity_<placeholder<I> > {
NDNBOOST_STATIC_CONSTANT(int, value = I);
};
} // detail
template<class T>
struct get_tuple_arity {
NDNBOOST_STATIC_CONSTANT(int, value = get_arity<typename T::head_type>::value | get_tuple_arity<typename T::tail_type>::value);
};
template<>
struct get_tuple_arity<null_type> {
NDNBOOST_STATIC_CONSTANT(int, value = 0);
};
// Does T have placeholder<I> as it's subexpression?
template<class T, int I>
struct has_placeholder {
NDNBOOST_STATIC_CONSTANT(bool, value = (get_arity<T>::value & I) != 0);
};
template<int I, int J>
struct includes_placeholder {
NDNBOOST_STATIC_CONSTANT(bool, value = (J & I) != 0);
};
template<int I, int J>
struct lacks_placeholder {
NDNBOOST_STATIC_CONSTANT(bool, value = ((J & I) == 0));
};
} // namespace lambda
} // namespace ndnboost
#endif