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// Boost Lambda Library lambda_functor_base.hpp -----------------------------
//
// 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 BOOST_LAMBDA_LAMBDA_FUNCTOR_BASE_HPP
#define BOOST_LAMBDA_LAMBDA_FUNCTOR_BASE_HPP
#include "ndnboost/type_traits/add_reference.hpp"
#include "ndnboost/type_traits/add_const.hpp"
#include "ndnboost/type_traits/remove_const.hpp"
#include "ndnboost/lambda/detail/lambda_fwd.hpp"
#include "ndnboost/lambda/detail/lambda_traits.hpp"
namespace ndnboost {
namespace lambda {
#if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
#pragma warning(push)
#pragma warning(disable:4512) //assignment operator could not be generated
#endif
// for return type deductions we wrap bound argument to this class,
// which fulfils the base class contract for lambda_functors
template <class T>
class identity {
T elem;
public:
typedef T element_t;
// take all parameters as const references. Note that non-const references
// stay as they are.
typedef typename ndnboost::add_reference<
typename ndnboost::add_const<T>::type
>::type par_t;
explicit identity(par_t t) : elem(t) {}
template <typename SigArgs>
struct sig { typedef typename ndnboost::remove_const<element_t>::type type; };
template<class RET, CALL_TEMPLATE_ARGS>
RET call(CALL_FORMAL_ARGS) const { CALL_USE_ARGS; return elem; }
};
#if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
#pragma warning(pop)
#endif
template <class T>
inline lambda_functor<identity<T&> > var(T& t) { return identity<T&>(t); }
// for lambda functors, var is an identity operator. It was forbidden
// at some point, but we might want to var something that can be a
// non-lambda functor or a lambda functor.
template <class T>
lambda_functor<T> var(const lambda_functor<T>& t) { return t; }
template <class T> struct var_type {
typedef lambda_functor<identity<T&> > type;
};
template <class T>
inline
lambda_functor<identity<typename bound_argument_conversion<const T>::type> >
constant(const T& t) {
return identity<typename bound_argument_conversion<const T>::type>(t);
}
template <class T>
lambda_functor<T> constant(const lambda_functor<T>& t) { return t; }
template <class T> struct constant_type {
typedef
lambda_functor<
identity<typename bound_argument_conversion<const T>::type>
> type;
};
template <class T>
inline lambda_functor<identity<const T&> > constant_ref(const T& t) {
return identity<const T&>(t);
}
template <class T>
lambda_functor<T> constant_ref(const lambda_functor<T>& t) { return t; }
template <class T> struct constant_ref_type {
typedef
lambda_functor<identity<const T&> > type;
};
// as_lambda_functor turns any types to lambda functors
// non-lambda_functors will be bound argument types
template <class T>
struct as_lambda_functor {
typedef typename
detail::remove_reference_and_cv<T>::type plain_T;
typedef typename
detail::IF<is_lambda_functor<plain_T>::value,
plain_T,
lambda_functor<
identity<typename bound_argument_conversion<T>::type>
>
>::RET type;
};
// turns arbitrary objects into lambda functors
template <class T>
inline
lambda_functor<identity<typename bound_argument_conversion<const T>::type> >
to_lambda_functor(const T& t) {
return identity<typename bound_argument_conversion<const T>::type>(t);
}
template <class T>
inline lambda_functor<T>
to_lambda_functor(const lambda_functor<T>& t) {
return t;
}
namespace detail {
// In a call constify_rvals<T>::go(x)
// x should be of type T. If T is a non-reference type, do
// returns x as const reference.
// Otherwise the type doesn't change.
// The purpose of this class is to avoid
// 'cannot bind temporaries to non-const references' errors.
template <class T> struct constify_rvals {
template<class U>
static inline const U& go(const U& u) { return u; }
};
template <class T> struct constify_rvals<T&> {
template<class U>
static inline U& go(U& u) { return u; }
};
// check whether one of the elements of a tuple (cons list) is of type
// null_type. Needed, because the compiler goes ahead and instantiates
// sig template for nullary case even if the nullary operator() is not
// called
template <class T> struct is_null_type
{ BOOST_STATIC_CONSTANT(bool, value = false); };
template <> struct is_null_type<null_type>
{ BOOST_STATIC_CONSTANT(bool, value = true); };
template<class Tuple> struct has_null_type {
BOOST_STATIC_CONSTANT(bool, value = (is_null_type<typename Tuple::head_type>::value || has_null_type<typename Tuple::tail_type>::value));
};
template<> struct has_null_type<null_type> {
BOOST_STATIC_CONSTANT(bool, value = false);
};
// helpers -------------------
template<class Args, class SigArgs>
class deduce_argument_types_ {
typedef typename as_lambda_functor<typename Args::head_type>::type lf_t;
typedef typename lf_t::inherited::template sig<SigArgs>::type el_t;
public:
typedef
ndnboost::tuples::cons<
el_t,
typename deduce_argument_types_<typename Args::tail_type, SigArgs>::type
> type;
};
template<class SigArgs>
class deduce_argument_types_<null_type, SigArgs> {
public:
typedef null_type type;
};
// // note that tuples cannot have plain function types as elements.
// // Hence, all other types will be non-const, except references to
// // functions.
// template <class T> struct remove_reference_except_from_functions {
// typedef typename ndnboost::remove_reference<T>::type t;
// typedef typename detail::IF<ndnboost::is_function<t>::value, T, t>::RET type;
// };
template<class Args, class SigArgs>
class deduce_non_ref_argument_types_ {
typedef typename as_lambda_functor<typename Args::head_type>::type lf_t;
typedef typename lf_t::inherited::template sig<SigArgs>::type el_t;
public:
typedef
ndnboost::tuples::cons<
// typename detail::remove_reference_except_from_functions<el_t>::type,
typename ndnboost::remove_reference<el_t>::type,
typename deduce_non_ref_argument_types_<typename Args::tail_type, SigArgs>::type
> type;
};
template<class SigArgs>
class deduce_non_ref_argument_types_<null_type, SigArgs> {
public:
typedef null_type type;
};
// -------------
// take stored Args and Open Args, and return a const list with
// deduced elements (real return types)
template<class Args, class SigArgs>
class deduce_argument_types {
typedef typename deduce_argument_types_<Args, SigArgs>::type t1;
public:
typedef typename detail::IF<
has_null_type<t1>::value, null_type, t1
>::RET type;
};
// take stored Args and Open Args, and return a const list with
// deduced elements (references are stripped from the element types)
template<class Args, class SigArgs>
class deduce_non_ref_argument_types {
typedef typename deduce_non_ref_argument_types_<Args, SigArgs>::type t1;
public:
typedef typename detail::IF<
has_null_type<t1>::value, null_type, t1
>::RET type;
};
template <int N, class Args, class SigArgs>
struct nth_return_type_sig {
typedef typename
as_lambda_functor<
typename ndnboost::tuples::element<N, Args>::type
// typename tuple_element_as_reference<N, Args>::type
>::type lf_type;
typedef typename lf_type::inherited::template sig<SigArgs>::type type;
};
template<int N, class Tuple> struct element_or_null {
typedef typename ndnboost::tuples::element<N, Tuple>::type type;
};
template<int N> struct element_or_null<N, null_type> {
typedef null_type type;
};
} // end detail
// -- lambda_functor base ---------------------
// the explicit_return_type_action case -----------------------------------
template<class RET, class Args>
class lambda_functor_base<explicit_return_type_action<RET>, Args>
{
public:
Args args;
typedef RET result_type;
explicit lambda_functor_base(const Args& a) : args(a) {}
template <class SigArgs> struct sig { typedef RET type; };
template<class RET_, CALL_TEMPLATE_ARGS>
RET call(CALL_FORMAL_ARGS) const
{
return detail::constify_rvals<RET>::go(
detail::r_select<RET>::go(ndnboost::tuples::get<0>(args), CALL_ACTUAL_ARGS));
}
};
// the protect_action case -----------------------------------
template<class Args>
class lambda_functor_base<protect_action, Args>
{
public:
Args args;
public:
explicit lambda_functor_base(const Args& a) : args(a) {}
template<class RET, CALL_TEMPLATE_ARGS>
RET call(CALL_FORMAL_ARGS) const
{
CALL_USE_ARGS;
return ndnboost::tuples::get<0>(args);
}
template<class SigArgs> struct sig {
// typedef typename detail::tuple_element_as_reference<0, SigArgs>::type type;
typedef typename ndnboost::tuples::element<0, Args>::type type;
};
};
// Do nothing --------------------------------------------------------
class do_nothing_action {};
template<class Args>
class lambda_functor_base<do_nothing_action, Args> {
// Args args;
public:
// explicit lambda_functor_base(const Args& a) {}
lambda_functor_base() {}
template<class RET, CALL_TEMPLATE_ARGS> RET call(CALL_FORMAL_ARGS) const {
return CALL_USE_ARGS;
}
template<class SigArgs> struct sig { typedef void type; };
};
// These specializations provide a shorter notation to define actions.
// These lambda_functor_base instances take care of the recursive evaluation
// of the arguments and pass the evaluated arguments to the apply function
// of an action class. To make action X work with these classes, one must
// instantiate the lambda_functor_base as:
// lambda_functor_base<action<ARITY, X>, Args>
// Where ARITY is the arity of the apply function in X
// The return type is queried as:
// return_type_N<X, EvaluatedArgumentTypes>::type
// for which there must be a specialization.
// Function actions, casts, throws,... all go via these classes.
template<class Act, class Args>
class lambda_functor_base<action<0, Act>, Args>
{
public:
// Args args; not needed
explicit lambda_functor_base(const Args& /*a*/) {}
template<class SigArgs> struct sig {
typedef typename return_type_N<Act, null_type>::type type;
};
template<class RET, CALL_TEMPLATE_ARGS>
RET call(CALL_FORMAL_ARGS) const {
CALL_USE_ARGS;
return Act::template apply<RET>();
}
};
#if defined BOOST_LAMBDA_LAMBDA_FUNCTOR_BASE_FIRST_PART
#error "Multiple defines of BOOST_LAMBDA_LAMBDA_FUNCTOR_BASE_FIRST_PART"
#endif
#define BOOST_LAMBDA_LAMBDA_FUNCTOR_BASE_FIRST_PART(ARITY) \
template<class Act, class Args> \
class lambda_functor_base<action<ARITY, Act>, Args> \
{ \
public: \
Args args; \
\
explicit lambda_functor_base(const Args& a) : args(a) {} \
\
template<class SigArgs> struct sig { \
typedef typename \
detail::deduce_argument_types<Args, SigArgs>::type rets_t; \
public: \
typedef typename \
return_type_N_prot<Act, rets_t>::type type; \
}; \
\
\
template<class RET, CALL_TEMPLATE_ARGS> \
RET call(CALL_FORMAL_ARGS) const { \
using ndnboost::tuples::get; \
using detail::constify_rvals; \
using detail::r_select; \
using detail::element_or_null; \
using detail::deduce_argument_types;
BOOST_LAMBDA_LAMBDA_FUNCTOR_BASE_FIRST_PART(1)
typedef typename
deduce_argument_types<Args, tuple<CALL_REFERENCE_TYPES> >::type rets_t;
typedef typename element_or_null<0, rets_t>::type rt0;
return Act::template apply<RET>(
constify_rvals<rt0>::go(r_select<rt0>::go(get<0>(args), CALL_ACTUAL_ARGS))
);
}
};
BOOST_LAMBDA_LAMBDA_FUNCTOR_BASE_FIRST_PART(2)
typedef typename
deduce_argument_types<Args, tuple<CALL_REFERENCE_TYPES> >::type rets_t;
typedef typename element_or_null<0, rets_t>::type rt0;
typedef typename element_or_null<1, rets_t>::type rt1;
return Act::template apply<RET>(
constify_rvals<rt0>::go(r_select<rt0>::go(get<0>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt1>::go(r_select<rt1>::go(get<1>(args), CALL_ACTUAL_ARGS))
);
}
};
BOOST_LAMBDA_LAMBDA_FUNCTOR_BASE_FIRST_PART(3)
typedef typename
deduce_argument_types<Args, tuple<CALL_REFERENCE_TYPES> >::type rets_t;
typedef typename element_or_null<0, rets_t>::type rt0;
typedef typename element_or_null<1, rets_t>::type rt1;
typedef typename element_or_null<2, rets_t>::type rt2;
return Act::template apply<RET>(
constify_rvals<rt0>::go(r_select<rt0>::go(get<0>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt1>::go(r_select<rt1>::go(get<1>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt2>::go(r_select<rt2>::go(get<2>(args), CALL_ACTUAL_ARGS))
);
}
};
BOOST_LAMBDA_LAMBDA_FUNCTOR_BASE_FIRST_PART(4)
typedef typename
deduce_argument_types<Args, tuple<CALL_REFERENCE_TYPES> >::type rets_t;
typedef typename element_or_null<0, rets_t>::type rt0;
typedef typename element_or_null<1, rets_t>::type rt1;
typedef typename element_or_null<2, rets_t>::type rt2;
typedef typename element_or_null<3, rets_t>::type rt3;
return Act::template apply<RET>(
constify_rvals<rt0>::go(r_select<rt0>::go(get<0>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt1>::go(r_select<rt1>::go(get<1>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt2>::go(r_select<rt2>::go(get<2>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt3>::go(r_select<rt3>::go(get<3>(args), CALL_ACTUAL_ARGS))
);
}
};
BOOST_LAMBDA_LAMBDA_FUNCTOR_BASE_FIRST_PART(5)
typedef typename
deduce_argument_types<Args, tuple<CALL_REFERENCE_TYPES> >::type rets_t;
typedef typename element_or_null<0, rets_t>::type rt0;
typedef typename element_or_null<1, rets_t>::type rt1;
typedef typename element_or_null<2, rets_t>::type rt2;
typedef typename element_or_null<3, rets_t>::type rt3;
typedef typename element_or_null<4, rets_t>::type rt4;
return Act::template apply<RET>(
constify_rvals<rt0>::go(r_select<rt0>::go(get<0>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt1>::go(r_select<rt1>::go(get<1>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt2>::go(r_select<rt2>::go(get<2>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt3>::go(r_select<rt3>::go(get<3>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt4>::go(r_select<rt4>::go(get<4>(args), CALL_ACTUAL_ARGS))
);
}
};
BOOST_LAMBDA_LAMBDA_FUNCTOR_BASE_FIRST_PART(6)
typedef typename
deduce_argument_types<Args, tuple<CALL_REFERENCE_TYPES> >::type rets_t;
typedef typename element_or_null<0, rets_t>::type rt0;
typedef typename element_or_null<1, rets_t>::type rt1;
typedef typename element_or_null<2, rets_t>::type rt2;
typedef typename element_or_null<3, rets_t>::type rt3;
typedef typename element_or_null<4, rets_t>::type rt4;
typedef typename element_or_null<5, rets_t>::type rt5;
return Act::template apply<RET>(
constify_rvals<rt0>::go(r_select<rt0>::go(get<0>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt1>::go(r_select<rt1>::go(get<1>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt2>::go(r_select<rt2>::go(get<2>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt3>::go(r_select<rt3>::go(get<3>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt4>::go(r_select<rt4>::go(get<4>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt5>::go(r_select<rt5>::go(get<5>(args), CALL_ACTUAL_ARGS))
);
}
};
BOOST_LAMBDA_LAMBDA_FUNCTOR_BASE_FIRST_PART(7)
typedef typename
deduce_argument_types<Args, tuple<CALL_REFERENCE_TYPES> >::type rets_t;
typedef typename element_or_null<0, rets_t>::type rt0;
typedef typename element_or_null<1, rets_t>::type rt1;
typedef typename element_or_null<2, rets_t>::type rt2;
typedef typename element_or_null<3, rets_t>::type rt3;
typedef typename element_or_null<4, rets_t>::type rt4;
typedef typename element_or_null<5, rets_t>::type rt5;
typedef typename element_or_null<6, rets_t>::type rt6;
return Act::template apply<RET>(
constify_rvals<rt0>::go(r_select<rt0>::go(get<0>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt1>::go(r_select<rt1>::go(get<1>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt2>::go(r_select<rt2>::go(get<2>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt3>::go(r_select<rt3>::go(get<3>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt4>::go(r_select<rt4>::go(get<4>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt5>::go(r_select<rt5>::go(get<5>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt6>::go(r_select<rt6>::go(get<6>(args), CALL_ACTUAL_ARGS))
);
}
};
BOOST_LAMBDA_LAMBDA_FUNCTOR_BASE_FIRST_PART(8)
typedef typename
deduce_argument_types<Args, tuple<CALL_REFERENCE_TYPES> >::type rets_t;
typedef typename element_or_null<0, rets_t>::type rt0;
typedef typename element_or_null<1, rets_t>::type rt1;
typedef typename element_or_null<2, rets_t>::type rt2;
typedef typename element_or_null<3, rets_t>::type rt3;
typedef typename element_or_null<4, rets_t>::type rt4;
typedef typename element_or_null<5, rets_t>::type rt5;
typedef typename element_or_null<6, rets_t>::type rt6;
typedef typename element_or_null<7, rets_t>::type rt7;
return Act::template apply<RET>(
constify_rvals<rt0>::go(r_select<rt0>::go(get<0>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt1>::go(r_select<rt1>::go(get<1>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt2>::go(r_select<rt2>::go(get<2>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt3>::go(r_select<rt3>::go(get<3>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt4>::go(r_select<rt4>::go(get<4>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt5>::go(r_select<rt5>::go(get<5>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt6>::go(r_select<rt6>::go(get<6>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt7>::go(r_select<rt7>::go(get<7>(args), CALL_ACTUAL_ARGS))
);
}
};
BOOST_LAMBDA_LAMBDA_FUNCTOR_BASE_FIRST_PART(9)
typedef typename
deduce_argument_types<Args, tuple<CALL_REFERENCE_TYPES> >::type rets_t;
typedef typename element_or_null<0, rets_t>::type rt0;
typedef typename element_or_null<1, rets_t>::type rt1;
typedef typename element_or_null<2, rets_t>::type rt2;
typedef typename element_or_null<3, rets_t>::type rt3;
typedef typename element_or_null<4, rets_t>::type rt4;
typedef typename element_or_null<5, rets_t>::type rt5;
typedef typename element_or_null<6, rets_t>::type rt6;
typedef typename element_or_null<7, rets_t>::type rt7;
typedef typename element_or_null<8, rets_t>::type rt8;
return Act::template apply<RET>(
constify_rvals<rt0>::go(r_select<rt0>::go(get<0>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt1>::go(r_select<rt1>::go(get<1>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt2>::go(r_select<rt2>::go(get<2>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt3>::go(r_select<rt3>::go(get<3>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt4>::go(r_select<rt4>::go(get<4>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt5>::go(r_select<rt5>::go(get<5>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt6>::go(r_select<rt6>::go(get<6>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt7>::go(r_select<rt7>::go(get<7>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt8>::go(r_select<rt8>::go(get<8>(args), CALL_ACTUAL_ARGS))
);
}
};
BOOST_LAMBDA_LAMBDA_FUNCTOR_BASE_FIRST_PART(10)
typedef typename
deduce_argument_types<Args, tuple<CALL_REFERENCE_TYPES> >::type rets_t;
typedef typename element_or_null<0, rets_t>::type rt0;
typedef typename element_or_null<1, rets_t>::type rt1;
typedef typename element_or_null<2, rets_t>::type rt2;
typedef typename element_or_null<3, rets_t>::type rt3;
typedef typename element_or_null<4, rets_t>::type rt4;
typedef typename element_or_null<5, rets_t>::type rt5;
typedef typename element_or_null<6, rets_t>::type rt6;
typedef typename element_or_null<7, rets_t>::type rt7;
typedef typename element_or_null<8, rets_t>::type rt8;
typedef typename element_or_null<9, rets_t>::type rt9;
return Act::template apply<RET>(
constify_rvals<rt0>::go(r_select<rt0>::go(get<0>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt1>::go(r_select<rt1>::go(get<1>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt2>::go(r_select<rt2>::go(get<2>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt3>::go(r_select<rt3>::go(get<3>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt4>::go(r_select<rt4>::go(get<4>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt5>::go(r_select<rt5>::go(get<5>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt6>::go(r_select<rt6>::go(get<6>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt7>::go(r_select<rt7>::go(get<7>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt8>::go(r_select<rt8>::go(get<8>(args), CALL_ACTUAL_ARGS)),
constify_rvals<rt9>::go(r_select<rt9>::go(get<9>(args), CALL_ACTUAL_ARGS))
);
}
};
#undef BOOST_LAMBDA_LAMBDA_FUNCTOR_BASE_FIRST_PART
} // namespace lambda
} // namespace ndnboost
#endif