asio/execution/prefer_only.hpp

66 template <typename InnerProperty, typename = void>
72 template <typename InnerProperty>
73 struct prefer_only_is_preferable<InnerProperty,
75       InnerProperty::is_preferable
81 template <typename InnerProperty, typename = void>
86 template <typename InnerProperty>
87 struct prefer_only_polymorphic_query_result_type<InnerProperty,
89       typename InnerProperty::polymorphic_query_result_type
92   typedef typename InnerProperty::polymorphic_query_result_type
96 template <typename InnerProperty, typename = void>
99   InnerProperty property;
101   prefer_only_property(const InnerProperty& p)
110 template <typename InnerProperty>
111 struct prefer_only_property<InnerProperty,
113       decltype(boost::asio::declval<const InnerProperty>().value())
116   InnerProperty property;
118   prefer_only_property(const InnerProperty& p)
125       noexcept(boost::asio::declval<const InnerProperty>().value())))
126     -> decltype(boost::asio::declval<const InnerProperty>().value())
160 template <typename InnerProperty>
161 struct prefer_only_property<InnerProperty,
163       sizeof(prefer_only_value_memfn_helper<InnerProperty>(0)) != 1
164         && !is_same<typename InnerProperty::polymorphic_query_result_type,
168   InnerProperty property;
170   prefer_only_property(const InnerProperty& p)
175   BOOST_ASIO_CONSTEXPR typename InnerProperty::polymorphic_query_result_type
187 template <typename InnerProperty>
189   detail::prefer_only_is_preferable<InnerProperty>,
190   detail::prefer_only_polymorphic_query_result_type<InnerProperty>,
191   detail::prefer_only_property<InnerProperty>
195   BOOST_ASIO_CONSTEXPR prefer_only(const InnerProperty& p)
196     : detail::prefer_only_property<InnerProperty>(p)
204   typename traits::static_query<T, InnerProperty>::result_type
207       traits::static_query<T, InnerProperty>::is_noexcept))
209     return traits::static_query<T, InnerProperty>::value();
220   typename prefer_result<const Executor&, const InnerProperty&>::type
223         is_same<Property, InnerProperty>::value
224           && can_prefer<const Executor&, const InnerProperty&>::value
229       is_nothrow_prefer<const Executor&, const InnerProperty&>::value))
238   typename query_result<const Executor&, const InnerProperty&>::type
241         is_same<Property, InnerProperty>::value
242           && can_query<const Executor&, const InnerProperty&>::value
247       is_nothrow_query<const Executor&, const InnerProperty&>::value))
257 template <typename InnerProperty> template <typename E, typename T>
258 const T prefer_only<InnerProperty>::static_query_v;
264 template <typename T, typename InnerProperty>
265 struct is_applicable_property<T, execution::prefer_only<InnerProperty> >
266   : is_applicable_property<T, InnerProperty>
275 template <typename T, typename InnerProperty>
276 struct static_query<T, execution::prefer_only<InnerProperty> > :
277   static_query<T, const InnerProperty&>
286 template <typename T, typename InnerProperty>
287 struct prefer_free_default<T, execution::prefer_only<InnerProperty>,
289       can_prefer<const T&, const InnerProperty&>::value
294     (is_nothrow_prefer<const T&, const InnerProperty&>::value));
297       const InnerProperty&>::type result_type;
304 template <typename T, typename InnerProperty>
305 struct query_free<T, execution::prefer_only<InnerProperty>,
307       can_query<const T&, const InnerProperty&>::value
312     (is_nothrow_query<const T&, const InnerProperty&>::value));
315       const InnerProperty&>::type result_type;