// Boost Lambda Library - lambda_functors.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 http://www.boost.org | |
// ------------------------------------------------ | |
#ifndef BOOST_LAMBDA_LAMBDA_FUNCTORS_HPP | |
#define BOOST_LAMBDA_LAMBDA_FUNCTORS_HPP | |
#include <boost/config.hpp> | |
#include <boost/detail/workaround.hpp> | |
#if BOOST_WORKAROUND(BOOST_MSVC, == 1310) | |
#include <boost/mpl/or.hpp> | |
#include <boost/utility/enable_if.hpp> | |
#include <boost/type_traits/is_array.hpp> | |
#define BOOST_LAMBDA_DISABLE_IF_ARRAY1(A1, R1)\ | |
typename lazy_disable_if<is_array<A1>, typename R1 >::type | |
#define BOOST_LAMBDA_DISABLE_IF_ARRAY2(A1, A2, R1, R2) \ | |
typename lazy_disable_if<mpl::or_<is_array<A1>, is_array<A2> >, typename R1, R2 >::type | |
#define BOOST_LAMBDA_DISABLE_IF_ARRAY3(A1, A2, A3, R1, R2, R3) \ | |
typename lazy_disable_if<mpl::or_<is_array<A1>, is_array<A2>, is_array<A3> >, typename R1, R2, R3 >::type | |
#else | |
#define BOOST_LAMBDA_DISABLE_IF_ARRAY1(A1, R1) typename R1::type | |
#define BOOST_LAMBDA_DISABLE_IF_ARRAY2(A1, A2, R1, R2) typename R1, R2::type | |
#define BOOST_LAMBDA_DISABLE_IF_ARRAY3(A1, A2, A3, R1, R2, R3) typename R1, R2, R3::type | |
#endif | |
namespace boost { | |
namespace lambda { | |
// -- lambda_functor -------------------------------------------- | |
// -------------------------------------------------------------- | |
//inline const null_type const_null_type() { return null_type(); } | |
namespace detail { | |
namespace { | |
static const null_type constant_null_type = null_type(); | |
} // unnamed | |
} // detail | |
class unused {}; | |
#define cnull_type() detail::constant_null_type | |
// -- free variables types -------------------------------------------------- | |
// helper to work around the case where the nullary return type deduction | |
// is always performed, even though the functor is not nullary | |
namespace detail { | |
template<int N, class Tuple> struct get_element_or_null_type { | |
typedef typename | |
detail::tuple_element_as_reference<N, Tuple>::type type; | |
}; | |
template<int N> struct get_element_or_null_type<N, null_type> { | |
typedef null_type type; | |
}; | |
} | |
template <int I> struct placeholder; | |
template<> struct placeholder<FIRST> { | |
template<class SigArgs> struct sig { | |
typedef typename detail::get_element_or_null_type<0, SigArgs>::type type; | |
}; | |
template<class RET, CALL_TEMPLATE_ARGS> | |
RET call(CALL_FORMAL_ARGS) const { | |
BOOST_STATIC_ASSERT(boost::is_reference<RET>::value); | |
CALL_USE_ARGS; // does nothing, prevents warnings for unused args | |
return a; | |
} | |
}; | |
template<> struct placeholder<SECOND> { | |
template<class SigArgs> struct sig { | |
typedef typename detail::get_element_or_null_type<1, SigArgs>::type type; | |
}; | |
template<class RET, CALL_TEMPLATE_ARGS> | |
RET call(CALL_FORMAL_ARGS) const { CALL_USE_ARGS; return b; } | |
}; | |
template<> struct placeholder<THIRD> { | |
template<class SigArgs> struct sig { | |
typedef typename detail::get_element_or_null_type<2, SigArgs>::type type; | |
}; | |
template<class RET, CALL_TEMPLATE_ARGS> | |
RET call(CALL_FORMAL_ARGS) const { CALL_USE_ARGS; return c; } | |
}; | |
template<> struct placeholder<EXCEPTION> { | |
template<class SigArgs> struct sig { | |
typedef typename detail::get_element_or_null_type<3, SigArgs>::type type; | |
}; | |
template<class RET, CALL_TEMPLATE_ARGS> | |
RET call(CALL_FORMAL_ARGS) const { CALL_USE_ARGS; return env; } | |
}; | |
typedef const lambda_functor<placeholder<FIRST> > placeholder1_type; | |
typedef const lambda_functor<placeholder<SECOND> > placeholder2_type; | |
typedef const lambda_functor<placeholder<THIRD> > placeholder3_type; | |
/////////////////////////////////////////////////////////////////////////////// | |
// free variables are lambda_functors. This is to allow uniform handling with | |
// other lambda_functors. | |
// ------------------------------------------------------------------- | |
#if BOOST_WORKAROUND(BOOST_MSVC, >= 1400) | |
#pragma warning(push) | |
#pragma warning(disable:4512) //assignment operator could not be generated | |
#endif | |
// -- lambda_functor NONE ------------------------------------------------ | |
template <class T> | |
class lambda_functor : public T | |
{ | |
BOOST_STATIC_CONSTANT(int, arity_bits = get_arity<T>::value); | |
public: | |
typedef T inherited; | |
lambda_functor() {} | |
lambda_functor(const lambda_functor& l) : inherited(l) {} | |
lambda_functor(const T& t) : inherited(t) {} | |
template <class SigArgs> struct sig { | |
typedef typename inherited::template | |
sig<typename SigArgs::tail_type>::type type; | |
}; | |
// Note that this return type deduction template is instantiated, even | |
// if the nullary | |
// operator() is not called at all. One must make sure that it does not fail. | |
typedef typename | |
inherited::template sig<null_type>::type | |
nullary_return_type; | |
// Support for boost::result_of. | |
template <class Sig> struct result; | |
template <class F> | |
struct result<F()> { | |
typedef nullary_return_type type; | |
}; | |
template <class F, class A> | |
struct result<F(A)> { | |
typedef typename sig<tuple<F, A> >::type type; | |
}; | |
template <class F, class A, class B> | |
struct result<F(A, B)> { | |
typedef typename sig<tuple<F, A, B> >::type type; | |
}; | |
template <class F, class A, class B, class C> | |
struct result<F(A, B, C)> { | |
typedef typename sig<tuple<F, A, B, C> >::type type; | |
}; | |
nullary_return_type operator()() const { | |
return inherited::template | |
call<nullary_return_type> | |
(cnull_type(), cnull_type(), cnull_type(), cnull_type()); | |
} | |
template<class A> | |
typename inherited::template sig<tuple<A&> >::type | |
operator()(A& a) const { | |
return inherited::template call< | |
typename inherited::template sig<tuple<A&> >::type | |
>(a, cnull_type(), cnull_type(), cnull_type()); | |
} | |
template<class A> | |
BOOST_LAMBDA_DISABLE_IF_ARRAY1(A, inherited::template sig<tuple<A const&> >) | |
operator()(A const& a) const { | |
return inherited::template call< | |
typename inherited::template sig<tuple<A const&> >::type | |
>(a, cnull_type(), cnull_type(), cnull_type()); | |
} | |
template<class A, class B> | |
typename inherited::template sig<tuple<A&, B&> >::type | |
operator()(A& a, B& b) const { | |
return inherited::template call< | |
typename inherited::template sig<tuple<A&, B&> >::type | |
>(a, b, cnull_type(), cnull_type()); | |
} | |
template<class A, class B> | |
BOOST_LAMBDA_DISABLE_IF_ARRAY2(A, B, inherited::template sig<tuple<A const&, B&> >) | |
operator()(A const& a, B& b) const { | |
return inherited::template call< | |
typename inherited::template sig<tuple<A const&, B&> >::type | |
>(a, b, cnull_type(), cnull_type()); | |
} | |
template<class A, class B> | |
BOOST_LAMBDA_DISABLE_IF_ARRAY2(A, B, inherited::template sig<tuple<A&, B const&> >) | |
operator()(A& a, B const& b) const { | |
return inherited::template call< | |
typename inherited::template sig<tuple<A&, B const&> >::type | |
>(a, b, cnull_type(), cnull_type()); | |
} | |
template<class A, class B> | |
BOOST_LAMBDA_DISABLE_IF_ARRAY2(A, B, inherited::template sig<tuple<A const&, B const&> >) | |
operator()(A const& a, B const& b) const { | |
return inherited::template call< | |
typename inherited::template sig<tuple<A const&, B const&> >::type | |
>(a, b, cnull_type(), cnull_type()); | |
} | |
template<class A, class B, class C> | |
typename inherited::template sig<tuple<A&, B&, C&> >::type | |
operator()(A& a, B& b, C& c) const | |
{ | |
return inherited::template call< | |
typename inherited::template sig<tuple<A&, B&, C&> >::type | |
>(a, b, c, cnull_type()); | |
} | |
template<class A, class B, class C> | |
BOOST_LAMBDA_DISABLE_IF_ARRAY3(A, B, C, inherited::template sig<tuple<A const&, B const&, C const&> >) | |
operator()(A const& a, B const& b, C const& c) const | |
{ | |
return inherited::template call< | |
typename inherited::template sig<tuple<A const&, B const&, C const&> >::type | |
>(a, b, c, cnull_type()); | |
} | |
// for internal calls with env | |
template<CALL_TEMPLATE_ARGS> | |
typename inherited::template sig<tuple<CALL_REFERENCE_TYPES> >::type | |
internal_call(CALL_FORMAL_ARGS) const { | |
return inherited::template | |
call<typename inherited::template | |
sig<tuple<CALL_REFERENCE_TYPES> >::type>(CALL_ACTUAL_ARGS); | |
} | |
template<class A> | |
const lambda_functor<lambda_functor_base< | |
other_action<assignment_action>, | |
boost::tuple<lambda_functor, | |
typename const_copy_argument <const A>::type> > > | |
operator=(const A& a) const { | |
return lambda_functor_base< | |
other_action<assignment_action>, | |
boost::tuple<lambda_functor, | |
typename const_copy_argument <const A>::type> > | |
( boost::tuple<lambda_functor, | |
typename const_copy_argument <const A>::type>(*this, a) ); | |
} | |
template<class A> | |
const lambda_functor<lambda_functor_base< | |
other_action<subscript_action>, | |
boost::tuple<lambda_functor, | |
typename const_copy_argument <const A>::type> > > | |
operator[](const A& a) const { | |
return lambda_functor_base< | |
other_action<subscript_action>, | |
boost::tuple<lambda_functor, | |
typename const_copy_argument <const A>::type> > | |
( boost::tuple<lambda_functor, | |
typename const_copy_argument <const A>::type>(*this, a ) ); | |
} | |
}; | |
#if BOOST_WORKAROUND(BOOST_MSVC, >= 1400) | |
#pragma warning(pop) | |
#endif | |
} // namespace lambda | |
} // namespace boost | |
// is_placeholder | |
#include <boost/is_placeholder.hpp> | |
namespace boost | |
{ | |
template<> struct is_placeholder< lambda::lambda_functor< lambda::placeholder<lambda::FIRST> > > | |
{ | |
enum _vt { value = 1 }; | |
}; | |
template<> struct is_placeholder< lambda::lambda_functor< lambda::placeholder<lambda::SECOND> > > | |
{ | |
enum _vt { value = 2 }; | |
}; | |
template<> struct is_placeholder< lambda::lambda_functor< lambda::placeholder<lambda::THIRD> > > | |
{ | |
enum _vt { value = 3 }; | |
}; | |
} // namespace boost | |
#endif |