diff options
Diffstat (limited to 'boost/type_erasure/free.hpp')
| -rw-r--r-- | boost/type_erasure/free.hpp | 242 |
1 files changed, 208 insertions, 34 deletions
diff --git a/boost/type_erasure/free.hpp b/boost/type_erasure/free.hpp index a2a6a7100a..23d1a67856 100644 --- a/boost/type_erasure/free.hpp +++ b/boost/type_erasure/free.hpp @@ -19,6 +19,9 @@ #include <boost/preprocessor/repetition/enum_params_with_a_default.hpp> #include <boost/preprocessor/repetition/enum_binary_params.hpp> #include <boost/preprocessor/cat.hpp> +#include <boost/preprocessor/control/if.hpp> +#include <boost/preprocessor/punctuation/is_begin_parens.hpp> +#include <boost/vmd/is_empty.hpp> #include <boost/type_traits/remove_reference.hpp> #include <boost/type_traits/remove_cv.hpp> #include <boost/mpl/eval_if.hpp> @@ -148,6 +151,64 @@ struct first_placeholder_index : } \ } +/** INTERNAL ONLY */ +#define BOOST_TYPE_ERASURE_FREE_I(namespace_name, concept_name, function_name, N)\ + BOOST_TYPE_ERASURE_FREE_II(namespace_name, concept_name, function_name, N) + +#ifdef BOOST_TYPE_ERASURE_DOXYGEN + +/** + * \brief Defines a primitive concept for a free function. + * + * \param concept_name is the name of the concept to declare. + * If it is omitted it defaults to <code>has_ ## function_name</code> + * \param function_name is the name of the function. + * + * The declaration of the concept is + * \code + * template<class Sig> + * struct concept_name; + * \endcode + * where Sig is a function type giving the + * signature of the function. + * + * This macro can only be used at namespace scope. + * + * Example: + * + * \code + * BOOST_TYPE_ERASURE_FREE(to_string) + * typedef has_to_string<std::string(_self const&)> to_string_concept; + * \endcode + * + * In C++03, the macro can only be used in the global namespace and + * is defined as: + * + * \code + * #define BOOST_TYPE_ERASURE_FREE(qualified_name, function_name, N) + * \endcode + * + * Example: + * + * \code + * BOOST_TYPE_ERASURE_FREE((boost)(has_to_string), to_string, 1) + * \endcode + * + * For backwards compatibility, this form is always accepted. + */ +#define BOOST_TYPE_ERASURE_FREE(concept_name, function_name) + +#else + +#define BOOST_TYPE_ERASURE_FREE(qualified_name, function_name, N) \ + BOOST_TYPE_ERASURE_FREE_I( \ + qualified_name, \ + BOOST_PP_SEQ_ELEM(BOOST_PP_DEC(BOOST_PP_SEQ_SIZE(qualified_name)), qualified_name), \ + function_name, \ + N) + +#endif + #else namespace boost { @@ -208,12 +269,143 @@ struct make_index_list<0> { typedef index_list<> type; }; -} -} -} +#if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES) && \ + !defined(BOOST_NO_CXX11_DECLTYPE) + +template<int N> +using make_index_list_t = typename ::boost::type_erasure::detail::make_index_list<N>::type; + +#if BOOST_WORKAROUND(BOOST_MSVC, == 1900) + +template<class... T> +struct first_placeholder_index_ : + ::boost::type_erasure::detail::first_placeholder_index< + ::boost::remove_cv_t< ::boost::remove_reference_t<T> >... + > +{}; +template<class... T> +using first_placeholder_index_t = + typename ::boost::type_erasure::detail::first_placeholder_index_<T...>::type; + +#else + +template<class... T> +using first_placeholder_index_t = + typename ::boost::type_erasure::detail::first_placeholder_index< + ::boost::remove_cv_t< ::boost::remove_reference_t<T> >... + >::type; + +#endif + +template<class Base, class Tn, int I, class... T> +using free_param_t = + typename ::boost::mpl::eval_if_c<(::boost::type_erasure::detail::first_placeholder_index_t<T...>::value == I), + ::boost::type_erasure::detail::maybe_const_this_param<Tn, Base>, \ + ::boost::type_erasure::as_param<Base, Tn> + >::type; + +template<class Sig, class ID> +struct free_interface_chooser +{ + template<class Base, template<class> class C, template<class...> class F> + using apply = Base; +}; + +template<class R, class... A> +struct free_interface_chooser< + R(A...), + typename ::boost::type_erasure::detail::first_placeholder< + ::boost::remove_cv_t< ::boost::remove_reference_t<A> >...>::type> +{ + template<class Base, template<class> class C, template<class...> class F> + using apply = F<R(A...), Base, + ::boost::type_erasure::detail::make_index_list_t<sizeof...(A)> >; +}; + +template<class Sig, template<class> class C, template<class...> class F> +struct free_choose_interface { + template<class Concept, class Base, class ID> + using apply = typename free_interface_chooser<Sig, ID>::template apply<Base, C, F>; +}; /** INTERNAL ONLY */ -#define BOOST_TYPE_ERASURE_FREE_II(qual_name, concept_name, function_name, N) \ +#define BOOST_TYPE_ERASURE_FREE_I(concept_name, function_name) \ +template<class Sig> \ +struct concept_name; \ + \ +namespace boost_type_erasure_impl { \ + \ +template<class Sig, class Base, class Idx> \ +struct concept_name ## _free_interface; \ +template<class R, class... T, class Base, int... I> \ +struct concept_name ## _free_interface<R(T...), Base, ::boost::type_erasure::index_list<I...> > : Base {\ + friend ::boost::type_erasure::rebind_any_t<Base, R> \ + function_name( \ + ::boost::type_erasure::detail::free_param_t<Base, T, I, T...>... t) \ + { \ + return ::boost::type_erasure::call( \ + concept_name<R(T...)>(), \ + std::forward< ::boost::type_erasure::detail::free_param_t<Base, T, I, T...> >(t)...);\ + } \ +}; \ + \ +template<class Sig> \ +struct concept_name ## free; \ + \ +template<class R, class... T> \ +struct concept_name ## free<R(T...)> { \ + static R apply(T... t) \ + { return function_name(std::forward<T>(t)...); } \ +}; \ + \ +template<class... T> \ +struct concept_name ## free<void(T...)> { \ + static void apply(T... t) \ + { function_name(std::forward<T>(t)...); } \ +}; \ + \ +} \ + \ +template<class Sig> \ +struct concept_name : \ + boost_type_erasure_impl::concept_name##free<Sig> \ +{}; \ + \ +template<class Sig> \ +::boost::type_erasure::detail::free_choose_interface<Sig, concept_name, \ + boost_type_erasure_impl::concept_name ## _free_interface> \ +boost_type_erasure_find_interface(concept_name<Sig>); + +#define BOOST_TYPE_ERASURE_FREE_SIMPLE(name, ...) \ + BOOST_TYPE_ERASURE_FREE_I(has_ ## name, name) + +#define BOOST_TYPE_ERASURE_FREE_NS_I(concept_name, name) \ + BOOST_TYPE_ERASURE_FREE_I(concept_name, name) + +#define BOOST_TYPE_ERASURE_FREE_NS(concept_name, name) \ + BOOST_TYPE_ERASURE_OPEN_NAMESPACE(concept_name) \ + BOOST_TYPE_ERASURE_FREE_NS_I(BOOST_PP_SEQ_ELEM(BOOST_PP_DEC(BOOST_PP_SEQ_SIZE(concept_name)), concept_name), name) \ + BOOST_TYPE_ERASURE_CLOSE_NAMESPACE(concept_name) + +#define BOOST_TYPE_ERASURE_FREE_NAMED(concept_name, name, ...) \ + BOOST_PP_IF(BOOST_PP_IS_BEGIN_PARENS(concept_name), \ + BOOST_TYPE_ERASURE_FREE_NS, \ + BOOST_TYPE_ERASURE_FREE_I) \ + (concept_name, name) + +#define BOOST_TYPE_ERASURE_FREE_CAT(x, y) x y + +#define BOOST_TYPE_ERASURE_FREE(name, ...) \ + BOOST_TYPE_ERASURE_FREE_CAT( \ + BOOST_PP_IF(BOOST_VMD_IS_EMPTY(__VA_ARGS__), \ + BOOST_TYPE_ERASURE_FREE_SIMPLE, \ + BOOST_TYPE_ERASURE_FREE_NAMED), \ + (name, __VA_ARGS__)) + +#else + +/** INTERNAL ONLY */ +#define BOOST_TYPE_ERASURE_FREE_II(qual_name, concept_name, function_name) \ BOOST_TYPE_ERASURE_OPEN_NAMESPACE(qual_name) \ \ template<class Sig> \ @@ -273,41 +465,23 @@ struct make_index_list<0> { } \ } -#endif /** INTERNAL ONLY */ -#define BOOST_TYPE_ERASURE_FREE_I(namespace_name, concept_name, function_name, N)\ - BOOST_TYPE_ERASURE_FREE_II(namespace_name, concept_name, function_name, N) +#define BOOST_TYPE_ERASURE_FREE_I(namespace_name, concept_name, function_name) \ + BOOST_TYPE_ERASURE_FREE_II(namespace_name, concept_name, function_name) -/** - * \brief Defines a primitive concept for a free function. - * - * \param qualified_name should be a preprocessor sequence - * of the form (namespace1)(namespace2)...(concept_name). - * \param function_name is the name of the function. - * \param N is the number of arguments of the function. - * - * The declaration of the concept is - * \code - * template<class Sig> - * struct ::namespace1::namespace2::...::concept_name; - * \endcode - * where Sig is a function type giving the - * signature of the function. - * - * This macro can only be used in the global namespace. - * - * Example: - * - * \code - * BOOST_TYPE_ERASURE_FREE((boost)(has_to_string), to_string, 1) - * \endcode - */ -#define BOOST_TYPE_ERASURE_FREE(qualified_name, function_name, N) \ +#define BOOST_TYPE_ERASURE_FREE(qualified_name, function_name, ...) \ BOOST_TYPE_ERASURE_FREE_I( \ qualified_name, \ BOOST_PP_SEQ_ELEM(BOOST_PP_DEC(BOOST_PP_SEQ_SIZE(qualified_name)), qualified_name), \ - function_name, \ - N) + function_name) + +#endif + +} +} +} + +#endif #endif |