Chris@16: // Boost Lambda Library -  lambda_functors.hpp -------------------------------
Chris@16: 
Chris@16: // Copyright (C) 1999, 2000 Jaakko Jarvi (jaakko.jarvi@cs.utu.fi)
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //
Chris@16: // For more information, see http://www.boost.org
Chris@16: 
Chris@16: // ------------------------------------------------
Chris@16: 
Chris@16: #ifndef BOOST_LAMBDA_LAMBDA_FUNCTORS_HPP
Chris@16: #define BOOST_LAMBDA_LAMBDA_FUNCTORS_HPP
Chris@16: 
Chris@16: #include <boost/config.hpp>
Chris@16: #include <boost/detail/workaround.hpp>
Chris@16: #include <boost/utility/result_of.hpp>
Chris@16: 
Chris@16: #if BOOST_WORKAROUND(BOOST_MSVC, == 1310)
Chris@16: 
Chris@16: #include <boost/mpl/or.hpp>
Chris@16: #include <boost/utility/enable_if.hpp>
Chris@16: #include <boost/type_traits/is_array.hpp>
Chris@16: 
Chris@16: #define BOOST_LAMBDA_DISABLE_IF_ARRAY1(A1, R1)\
Chris@16:   typename lazy_disable_if<is_array<A1>, typename R1 >::type
Chris@16: #define BOOST_LAMBDA_DISABLE_IF_ARRAY2(A1, A2, R1, R2) \
Chris@16:   typename lazy_disable_if<mpl::or_<is_array<A1>, is_array<A2> >, typename R1, R2 >::type
Chris@16: #define BOOST_LAMBDA_DISABLE_IF_ARRAY3(A1, A2, A3, R1, R2, R3) \
Chris@16:   typename lazy_disable_if<mpl::or_<is_array<A1>, is_array<A2>, is_array<A3> >, typename R1, R2, R3 >::type
Chris@16: 
Chris@16: #else
Chris@16: 
Chris@16: #define BOOST_LAMBDA_DISABLE_IF_ARRAY1(A1, R1) typename R1::type
Chris@16: #define BOOST_LAMBDA_DISABLE_IF_ARRAY2(A1, A2, R1, R2) typename R1, R2::type
Chris@16: #define BOOST_LAMBDA_DISABLE_IF_ARRAY3(A1, A2, A3, R1, R2, R3) typename R1, R2, R3::type
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16: namespace boost { 
Chris@16: namespace lambda {
Chris@16: 
Chris@16: // -- lambda_functor --------------------------------------------
Chris@16: // --------------------------------------------------------------
Chris@16: 
Chris@16: //inline const null_type const_null_type() { return null_type(); }
Chris@16: 
Chris@16: namespace detail {
Chris@16: namespace {
Chris@16: 
Chris@16:   static const null_type constant_null_type = null_type();
Chris@16: 
Chris@16: } // unnamed
Chris@16: } // detail
Chris@16: 
Chris@16: class unused {};
Chris@16: 
Chris@16: #define cnull_type() detail::constant_null_type
Chris@16: 
Chris@16: // -- free variables types -------------------------------------------------- 
Chris@16:  
Chris@16:   // helper to work around the case where the nullary return type deduction 
Chris@16:   // is always performed, even though the functor is not nullary  
Chris@16: namespace detail {
Chris@16:   template<int N, class Tuple> struct get_element_or_null_type {
Chris@16:     typedef typename 
Chris@16:       detail::tuple_element_as_reference<N, Tuple>::type type;
Chris@16:   };
Chris@16:   template<int N> struct get_element_or_null_type<N, null_type> {
Chris@16:     typedef null_type type;
Chris@16:   };
Chris@16: }
Chris@16: 
Chris@16: template <int I> struct placeholder;
Chris@16: 
Chris@16: template<> struct placeholder<FIRST> {
Chris@16: 
Chris@16:   template<class SigArgs> struct sig {
Chris@16:     typedef typename detail::get_element_or_null_type<0, SigArgs>::type type;
Chris@16:   };
Chris@16: 
Chris@16:   template<class RET, CALL_TEMPLATE_ARGS> 
Chris@16:   RET call(CALL_FORMAL_ARGS) const { 
Chris@16:     BOOST_STATIC_ASSERT(boost::is_reference<RET>::value); 
Chris@16:     CALL_USE_ARGS; // does nothing, prevents warnings for unused args
Chris@16:     return a; 
Chris@16:   }
Chris@16: };
Chris@16: 
Chris@16: template<> struct placeholder<SECOND> {
Chris@16: 
Chris@16:   template<class SigArgs> struct sig {
Chris@16:     typedef typename detail::get_element_or_null_type<1, SigArgs>::type type;
Chris@16:   };
Chris@16: 
Chris@16:   template<class RET, CALL_TEMPLATE_ARGS> 
Chris@16:   RET call(CALL_FORMAL_ARGS) const { CALL_USE_ARGS; return b; }
Chris@16: };
Chris@16: 
Chris@16: template<> struct placeholder<THIRD> {
Chris@16: 
Chris@16:   template<class SigArgs> struct sig {
Chris@16:     typedef typename detail::get_element_or_null_type<2, SigArgs>::type type;
Chris@16:   };
Chris@16: 
Chris@16:   template<class RET, CALL_TEMPLATE_ARGS> 
Chris@16:   RET call(CALL_FORMAL_ARGS) const { CALL_USE_ARGS; return c; }
Chris@16: };
Chris@16: 
Chris@16: template<> struct placeholder<EXCEPTION> {
Chris@16: 
Chris@16:   template<class SigArgs> struct sig {
Chris@16:     typedef typename detail::get_element_or_null_type<3, SigArgs>::type type;
Chris@16:   };
Chris@16: 
Chris@16:   template<class RET, CALL_TEMPLATE_ARGS> 
Chris@16:   RET call(CALL_FORMAL_ARGS) const { CALL_USE_ARGS; return env; }
Chris@16: };
Chris@16:    
Chris@16: typedef const lambda_functor<placeholder<FIRST> >  placeholder1_type;
Chris@16: typedef const lambda_functor<placeholder<SECOND> > placeholder2_type;
Chris@16: typedef const lambda_functor<placeholder<THIRD> >  placeholder3_type;
Chris@16:    
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: 
Chris@16: // free variables are lambda_functors. This is to allow uniform handling with 
Chris@16: // other lambda_functors.
Chris@16: // -------------------------------------------------------------------
Chris@16: 
Chris@16: #if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
Chris@16: #pragma warning(push)
Chris@16: #pragma warning(disable:4512) //assignment operator could not be generated
Chris@16: #endif
Chris@16: 
Chris@16: // -- lambda_functor NONE ------------------------------------------------
Chris@16: template <class T>
Chris@16: class lambda_functor : public T 
Chris@16: {
Chris@16: 
Chris@16: BOOST_STATIC_CONSTANT(int, arity_bits = get_arity<T>::value);
Chris@16:  
Chris@16: public:
Chris@16:   typedef T inherited;
Chris@16: 
Chris@16:   lambda_functor() {}
Chris@16:   lambda_functor(const lambda_functor& l) : inherited(l) {}
Chris@16: 
Chris@16:   lambda_functor(const T& t) : inherited(t) {}
Chris@16: 
Chris@16:   template <class SigArgs> struct sig {
Chris@16:     typedef typename inherited::template 
Chris@16:       sig<typename SigArgs::tail_type>::type type;
Chris@16:   };
Chris@16: 
Chris@16:   // Note that this return type deduction template is instantiated, even 
Chris@16:   // if the nullary 
Chris@16:   // operator() is not called at all. One must make sure that it does not fail.
Chris@16:   typedef typename 
Chris@16:     inherited::template sig<null_type>::type
Chris@16:       nullary_return_type;
Chris@16: 
Chris@16:   // Support for boost::result_of.
Chris@16:   template <class Sig> struct result;
Chris@16:   template <class F>
Chris@16:   struct result<F()> {
Chris@16:     typedef nullary_return_type type;
Chris@16:   };
Chris@16:   template <class F, class A>
Chris@16:   struct result<F(A)> {
Chris@16:     typedef typename sig<tuple<F, A> >::type type;
Chris@16:   };
Chris@16:   template <class F, class A, class B>
Chris@16:   struct result<F(A, B)> {
Chris@16:     typedef typename sig<tuple<F, A, B> >::type type;
Chris@16:   };
Chris@16:   template <class F, class A, class B, class C>
Chris@16:   struct result<F(A, B, C)> {
Chris@16:     typedef typename sig<tuple<F, A, B, C> >::type type;
Chris@16:   };
Chris@16: 
Chris@16:   nullary_return_type operator()() const { 
Chris@16:     return inherited::template 
Chris@16:       call<nullary_return_type>
Chris@16:         (cnull_type(), cnull_type(), cnull_type(), cnull_type()); 
Chris@16:   }
Chris@16: 
Chris@16:   template<class A>
Chris@16:   typename inherited::template sig<tuple<A&> >::type
Chris@16:   operator()(A& a) const { 
Chris@16:     return inherited::template call<
Chris@16:       typename inherited::template sig<tuple<A&> >::type
Chris@16:     >(a, cnull_type(), cnull_type(), cnull_type());
Chris@16:   }
Chris@16: 
Chris@16:   template<class A>
Chris@16:   BOOST_LAMBDA_DISABLE_IF_ARRAY1(A, inherited::template sig<tuple<A const&> >)
Chris@16:   operator()(A const& a) const { 
Chris@16:     return inherited::template call<
Chris@16:       typename inherited::template sig<tuple<A const&> >::type
Chris@16:     >(a, cnull_type(), cnull_type(), cnull_type());
Chris@16:   }
Chris@16: 
Chris@16:   template<class A, class B>
Chris@16:   typename inherited::template sig<tuple<A&, B&> >::type
Chris@16:   operator()(A& a, B& b) const { 
Chris@16:     return inherited::template call<
Chris@16:       typename inherited::template sig<tuple<A&, B&> >::type
Chris@16:     >(a, b, cnull_type(), cnull_type()); 
Chris@16:   }
Chris@16: 
Chris@16:   template<class A, class B>
Chris@16:   BOOST_LAMBDA_DISABLE_IF_ARRAY2(A, B, inherited::template sig<tuple<A const&, B&> >)
Chris@16:   operator()(A const& a, B& b) const { 
Chris@16:     return inherited::template call<
Chris@16:       typename inherited::template sig<tuple<A const&, B&> >::type
Chris@16:     >(a, b, cnull_type(), cnull_type()); 
Chris@16:   }
Chris@16: 
Chris@16:   template<class A, class B>
Chris@16:   BOOST_LAMBDA_DISABLE_IF_ARRAY2(A, B, inherited::template sig<tuple<A&, B const&> >)
Chris@16:   operator()(A& a, B const& b) const { 
Chris@16:     return inherited::template call<
Chris@16:       typename inherited::template sig<tuple<A&, B const&> >::type
Chris@16:     >(a, b, cnull_type(), cnull_type()); 
Chris@16:   }
Chris@16: 
Chris@16:   template<class A, class B>
Chris@16:   BOOST_LAMBDA_DISABLE_IF_ARRAY2(A, B, inherited::template sig<tuple<A const&, B const&> >)
Chris@16:   operator()(A const& a, B const& b) const { 
Chris@16:     return inherited::template call<
Chris@16:       typename inherited::template sig<tuple<A const&, B const&> >::type
Chris@16:     >(a, b, cnull_type(), cnull_type()); 
Chris@16:   }
Chris@16: 
Chris@16:   template<class A, class B, class C>
Chris@16:   typename inherited::template sig<tuple<A&, B&, C&> >::type
Chris@16:   operator()(A& a, B& b, C& c) const
Chris@16:   { 
Chris@16:     return inherited::template call<
Chris@16:       typename inherited::template sig<tuple<A&, B&, C&> >::type
Chris@16:     >(a, b, c, cnull_type()); 
Chris@16:   }
Chris@16: 
Chris@16:   template<class A, class B, class C>
Chris@16:   BOOST_LAMBDA_DISABLE_IF_ARRAY3(A, B, C, inherited::template sig<tuple<A const&, B const&, C const&> >)
Chris@16:   operator()(A const& a, B const& b, C const& c) const
Chris@16:   { 
Chris@16:     return inherited::template call<
Chris@16:       typename inherited::template sig<tuple<A const&, B const&, C const&> >::type
Chris@16:     >(a, b, c, cnull_type()); 
Chris@16:   }
Chris@16: 
Chris@16:   // for internal calls with env
Chris@16:   template<CALL_TEMPLATE_ARGS>
Chris@16:   typename inherited::template sig<tuple<CALL_REFERENCE_TYPES> >::type
Chris@16:   internal_call(CALL_FORMAL_ARGS) const { 
Chris@16:      return inherited::template 
Chris@16:        call<typename inherited::template 
Chris@16:          sig<tuple<CALL_REFERENCE_TYPES> >::type>(CALL_ACTUAL_ARGS); 
Chris@16:   }
Chris@16: 
Chris@16:   template<class A>
Chris@16:   const lambda_functor<lambda_functor_base<
Chris@16:                   other_action<assignment_action>,
Chris@16:                   boost::tuple<lambda_functor,
Chris@16:                   typename const_copy_argument <const A>::type> > >
Chris@16:   operator=(const A& a) const {
Chris@16:     return lambda_functor_base<
Chris@16:                   other_action<assignment_action>,
Chris@16:                   boost::tuple<lambda_functor,
Chris@16:                   typename const_copy_argument <const A>::type> >
Chris@16:      (  boost::tuple<lambda_functor,
Chris@16:              typename const_copy_argument <const A>::type>(*this, a) );
Chris@16:   }
Chris@16: 
Chris@16:   template<class A> 
Chris@16:   const lambda_functor<lambda_functor_base< 
Chris@16:                   other_action<subscript_action>, 
Chris@16:                   boost::tuple<lambda_functor, 
Chris@16:                         typename const_copy_argument <const A>::type> > > 
Chris@16:   operator[](const A& a) const { 
Chris@16:     return lambda_functor_base< 
Chris@16:                   other_action<subscript_action>, 
Chris@16:                   boost::tuple<lambda_functor, 
Chris@16:                         typename const_copy_argument <const A>::type> >
Chris@16:      ( boost::tuple<lambda_functor, 
Chris@16:              typename const_copy_argument <const A>::type>(*this, a ) ); 
Chris@16:   } 
Chris@16: };
Chris@16: 
Chris@16: #if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
Chris@16: #pragma warning(pop)
Chris@16: #endif
Chris@16: 
Chris@16: } // namespace lambda
Chris@16: } // namespace boost
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16: #if !defined(BOOST_RESULT_OF_USE_DECLTYPE) || defined(BOOST_NO_DECLTYPE)
Chris@16: 
Chris@16: template<class T>
Chris@16: struct result_of<boost::lambda::lambda_functor<T>()>
Chris@16: {
Chris@16:     typedef typename boost::lambda::lambda_functor<T>::nullary_return_type type;
Chris@16: };
Chris@16: 
Chris@16: template<class T>
Chris@16: struct result_of<const boost::lambda::lambda_functor<T>()>
Chris@16: {
Chris@16:     typedef typename boost::lambda::lambda_functor<T>::nullary_return_type type;
Chris@16: };
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16: template<class T>
Chris@16: struct tr1_result_of<boost::lambda::lambda_functor<T>()>
Chris@16: {
Chris@16:     typedef typename boost::lambda::lambda_functor<T>::nullary_return_type type;
Chris@16: };
Chris@16: 
Chris@16: template<class T>
Chris@16: struct tr1_result_of<const boost::lambda::lambda_functor<T>()>
Chris@16: {
Chris@16:     typedef typename boost::lambda::lambda_functor<T>::nullary_return_type type;
Chris@16: };
Chris@16: 
Chris@16: }
Chris@16: 
Chris@16: // is_placeholder
Chris@16: 
Chris@16: #include <boost/is_placeholder.hpp>
Chris@16: 
Chris@16: namespace boost
Chris@16: {
Chris@16: 
Chris@16: template<> struct is_placeholder< lambda::lambda_functor< lambda::placeholder<lambda::FIRST> > >
Chris@16: {
Chris@16:     enum _vt { value = 1 };
Chris@16: };
Chris@16: 
Chris@16: template<> struct is_placeholder< lambda::lambda_functor< lambda::placeholder<lambda::SECOND> > >
Chris@16: {
Chris@16:     enum _vt { value = 2 };
Chris@16: };
Chris@16: 
Chris@16: template<> struct is_placeholder< lambda::lambda_functor< lambda::placeholder<lambda::THIRD> > >
Chris@16: {
Chris@16:     enum _vt { value = 3 };
Chris@16: };
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #endif