Chris@16: // Boost result_of library
Chris@16: 
Chris@16: //  Copyright Douglas Gregor 2004. Use, modification and
Chris@16: //  distribution is subject to the Boost Software License, Version
Chris@16: //  1.0. (See 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/libs/utility
Chris@16: #ifndef BOOST_RESULT_OF_HPP
Chris@16: #define BOOST_RESULT_OF_HPP
Chris@16: 
Chris@16: #include <boost/config.hpp>
Chris@16: #include <boost/preprocessor/cat.hpp>
Chris@16: #include <boost/preprocessor/iteration/iterate.hpp>
Chris@16: #include <boost/preprocessor/repetition/enum_params.hpp>
Chris@16: #include <boost/preprocessor/repetition/enum_trailing_params.hpp>
Chris@16: #include <boost/preprocessor/repetition/enum_binary_params.hpp>
Chris@16: #include <boost/preprocessor/repetition/enum_shifted_params.hpp>
Chris@16: #include <boost/preprocessor/facilities/intercept.hpp>
Chris@16: #include <boost/detail/workaround.hpp>
Chris@16: #include <boost/mpl/has_xxx.hpp>
Chris@16: #include <boost/mpl/if.hpp>
Chris@16: #include <boost/mpl/eval_if.hpp>
Chris@16: #include <boost/mpl/bool.hpp>
Chris@16: #include <boost/mpl/identity.hpp>
Chris@16: #include <boost/mpl/or.hpp>
Chris@16: #include <boost/type_traits/is_class.hpp>
Chris@16: #include <boost/type_traits/is_pointer.hpp>
Chris@16: #include <boost/type_traits/is_member_function_pointer.hpp>
Chris@16: #include <boost/type_traits/remove_cv.hpp>
Chris@16: #include <boost/type_traits/remove_reference.hpp>
Chris@16: #include <boost/utility/declval.hpp>
Chris@16: #include <boost/utility/enable_if.hpp>
Chris@16: 
Chris@16: #ifndef BOOST_RESULT_OF_NUM_ARGS
Chris@16: #  define BOOST_RESULT_OF_NUM_ARGS 16
Chris@16: #endif
Chris@16: 
Chris@16: // Use the decltype-based version of result_of by default if the compiler
Chris@16: // supports N3276 <http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2011/n3276.pdf>.
Chris@16: // The user can force the choice by defining BOOST_RESULT_OF_USE_DECLTYPE,
Chris@16: // BOOST_RESULT_OF_USE_TR1, or BOOST_RESULT_OF_USE_TR1_WITH_DECLTYPE_FALLBACK but not more than one!
Chris@16: #if (defined(BOOST_RESULT_OF_USE_DECLTYPE) && defined(BOOST_RESULT_OF_USE_TR1)) || \
Chris@16:     (defined(BOOST_RESULT_OF_USE_DECLTYPE) && defined(BOOST_RESULT_OF_USE_TR1_WITH_DECLTYPE_FALLBACK)) || \
Chris@16:     (defined(BOOST_RESULT_OF_USE_TR1) && defined(BOOST_RESULT_OF_USE_TR1_WITH_DECLTYPE_FALLBACK))
Chris@16: #  error More than one of BOOST_RESULT_OF_USE_DECLTYPE, BOOST_RESULT_OF_USE_TR1 and \
Chris@16:   BOOST_RESULT_OF_USE_TR1_WITH_DECLTYPE_FALLBACK cannot be defined at the same time.
Chris@16: #endif
Chris@16: 
Chris@16: #if defined(BOOST_RESULT_OF_USE_TR1_WITH_DECLTYPE_FALLBACK) && defined(BOOST_MPL_CFG_NO_HAS_XXX_TEMPLATE)
Chris@16: #  error Cannot fallback to decltype if BOOST_MPL_CFG_NO_HAS_XXX_TEMPLATE is not defined.
Chris@16: #endif
Chris@16: 
Chris@16: #ifndef BOOST_RESULT_OF_USE_TR1
Chris@16: #  ifndef BOOST_RESULT_OF_USE_DECLTYPE
Chris@16: #    ifndef BOOST_RESULT_OF_USE_TR1_WITH_DECLTYPE_FALLBACK
Chris@16: #      ifndef BOOST_NO_CXX11_DECLTYPE_N3276 // this implies !defined(BOOST_NO_CXX11_DECLTYPE)
Chris@16: #        define BOOST_RESULT_OF_USE_DECLTYPE
Chris@16: #      else
Chris@16: #        define BOOST_RESULT_OF_USE_TR1
Chris@16: #      endif
Chris@16: #    endif
Chris@16: #  endif
Chris@16: #endif
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16: template<typename F> struct result_of;
Chris@16: template<typename F> struct tr1_result_of; // a TR1-style implementation of result_of
Chris@16: 
Chris@101: #if !defined(BOOST_NO_SFINAE)
Chris@16: namespace detail {
Chris@16: 
Chris@16: BOOST_MPL_HAS_XXX_TRAIT_DEF(result_type)
Chris@16: 
Chris@101: // Work around a nvcc bug by only defining has_result when it's needed.
Chris@101: #ifdef BOOST_RESULT_OF_USE_TR1_WITH_DECLTYPE_FALLBACK
Chris@16: BOOST_MPL_HAS_XXX_TEMPLATE_DEF(result)
Chris@101: #endif
Chris@16: 
Chris@16: template<typename F, typename FArgs, bool HasResultType> struct tr1_result_of_impl;
Chris@16: 
Chris@16: template<typename F> struct cpp0x_result_of;
Chris@16: 
Chris@16: #ifdef BOOST_NO_SFINAE_EXPR
Chris@16: 
Chris@16: // There doesn't seem to be any other way to turn this off such that the presence of
Chris@16: // the user-defined operator,() below doesn't cause spurious warning all over the place,
Chris@16: // so unconditionally turn it off.
Chris@16: #if BOOST_MSVC
Chris@16: #  pragma warning(disable: 4913) // user defined binary operator ',' exists but no overload could convert all operands, default built-in binary operator ',' used
Chris@16: #endif
Chris@16: 
Chris@16: struct result_of_private_type {};
Chris@16: 
Chris@16: struct result_of_weird_type {
Chris@16:   friend result_of_private_type operator,(result_of_private_type, result_of_weird_type);
Chris@16: };
Chris@16: 
Chris@16: typedef char result_of_yes_type;      // sizeof(result_of_yes_type) == 1
Chris@16: typedef char (&result_of_no_type)[2]; // sizeof(result_of_no_type)  == 2
Chris@16: 
Chris@16: template<typename T>
Chris@16: result_of_no_type result_of_is_private_type(T const &);
Chris@16: result_of_yes_type result_of_is_private_type(result_of_private_type);
Chris@16: 
Chris@16: template<typename C>
Chris@16: struct result_of_callable_class : C {
Chris@16:     result_of_callable_class();
Chris@16:     typedef result_of_private_type const &(*pfn_t)(...);
Chris@16:     operator pfn_t() const volatile;
Chris@16: };
Chris@16: 
Chris@16: template<typename C>
Chris@16: struct result_of_wrap_callable_class {
Chris@16:   typedef result_of_callable_class<C> type;
Chris@16: };
Chris@16: 
Chris@16: template<typename C>
Chris@16: struct result_of_wrap_callable_class<C const> {
Chris@16:   typedef result_of_callable_class<C> const type;
Chris@16: };
Chris@16: 
Chris@16: template<typename C>
Chris@16: struct result_of_wrap_callable_class<C volatile> {
Chris@16:   typedef result_of_callable_class<C> volatile type;
Chris@16: };
Chris@16: 
Chris@16: template<typename C>
Chris@16: struct result_of_wrap_callable_class<C const volatile> {
Chris@16:   typedef result_of_callable_class<C> const volatile type;
Chris@16: };
Chris@16: 
Chris@16: template<typename C>
Chris@16: struct result_of_wrap_callable_class<C &> {
Chris@16:   typedef typename result_of_wrap_callable_class<C>::type &type;
Chris@16: };
Chris@16: 
Chris@16: template<typename F, bool TestCallability = true> struct cpp0x_result_of_impl;
Chris@16: 
Chris@16: #else // BOOST_NO_SFINAE_EXPR
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct result_of_always_void
Chris@16: {
Chris@16:   typedef void type;
Chris@16: };
Chris@16: 
Chris@16: template<typename F, typename Enable = void> struct cpp0x_result_of_impl {};
Chris@16: 
Chris@16: #endif // BOOST_NO_SFINAE_EXPR
Chris@16: 
Chris@16: template<typename F>
Chris@16: struct result_of_void_impl
Chris@16: {
Chris@16:   typedef void type;
Chris@16: };
Chris@16: 
Chris@16: template<typename R>
Chris@16: struct result_of_void_impl<R (*)(void)>
Chris@16: {
Chris@16:   typedef R type;
Chris@16: };
Chris@16: 
Chris@16: template<typename R>
Chris@16: struct result_of_void_impl<R (&)(void)>
Chris@16: {
Chris@16:   typedef R type;
Chris@16: };
Chris@16: 
Chris@16: // Determine the return type of a function pointer or pointer to member.
Chris@16: template<typename F, typename FArgs>
Chris@16: struct result_of_pointer
Chris@16:   : tr1_result_of_impl<typename remove_cv<F>::type, FArgs, false> { };
Chris@16: 
Chris@16: template<typename F, typename FArgs>
Chris@16: struct tr1_result_of_impl<F, FArgs, true>
Chris@16: {
Chris@16:   typedef typename F::result_type type;
Chris@16: };
Chris@16: 
Chris@16: template<typename FArgs>
Chris@16: struct is_function_with_no_args : mpl::false_ {};
Chris@16: 
Chris@16: template<typename F>
Chris@16: struct is_function_with_no_args<F(void)> : mpl::true_ {};
Chris@16: 
Chris@16: template<typename F, typename FArgs>
Chris@16: struct result_of_nested_result : F::template result<FArgs>
Chris@16: {};
Chris@16: 
Chris@16: template<typename F, typename FArgs>
Chris@16: struct tr1_result_of_impl<F, FArgs, false>
Chris@16:   : mpl::if_<is_function_with_no_args<FArgs>,
Chris@16:              result_of_void_impl<F>,
Chris@16:              result_of_nested_result<F, FArgs> >::type
Chris@16: {};
Chris@16: 
Chris@16: } // end namespace detail
Chris@16: 
Chris@16: #define BOOST_PP_ITERATION_PARAMS_1 (3,(0,BOOST_RESULT_OF_NUM_ARGS,<boost/utility/detail/result_of_iterate.hpp>))
Chris@16: #include BOOST_PP_ITERATE()
Chris@16: 
Chris@16: #else
Chris@16: #  define BOOST_NO_RESULT_OF 1
Chris@16: #endif
Chris@16: 
Chris@16: }
Chris@16: 
Chris@16: #endif // BOOST_RESULT_OF_HPP