Rename to detail::is_invocable

Fix #323

include/beast/core/detail/is_call_possible.hpp

@@ -1,54 +0,0 @@
-//
-// Copyright (c) 2013-2017 Vinnie Falco (vinnie dot falco at gmail dot com)
-//
-// 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)
-//
-
-#ifndef BEAST_DETAIL_IS_CALL_POSSIBLE_HPP
-#define BEAST_DETAIL_IS_CALL_POSSIBLE_HPP
-
-#include <type_traits>
-
-namespace beast {
-namespace detail {
-
-template<class R, class C, class ...A>
-auto
-is_call_possible_test(C&& c, int, A&& ...a)
-    -> decltype(std::is_convertible<
-        decltype(c(a...)), R>::value ||
-            std::is_same<R, void>::value,
-                std::true_type());
-
-template<class R, class C, class ...A>
-std::false_type
-is_call_possible_test(C&& c, long, A&& ...a);
-
-/** Metafunction returns `true` if F callable as R(A...)
-
-    Example:
-
-    @code
-        is_call_possible<T, void(std::string)>
-    @endcode
-*/
-/** @{ */
-template<class C, class F>
-struct is_call_possible
-    : std::false_type
-{
-};
-
-template<class C, class R, class ...A>
-struct is_call_possible<C, R(A...)>
-    : decltype(is_call_possible_test<R>(
-        std::declval<C>(), 1, std::declval<A>()...))
-{
-};
-/** @} */
-
-} // detail
-} // beast
-
-#endif

include/beast/core/detail/type_traits.hpp

@@ -92,6 +92,41 @@ make_exception(char const* reason, char const* file, int line)
 		n + ":" + std::to_string(line) + ")"};
 }
 
+template<class R, class C, class ...A>
+auto
+is_invocable_test(C&& c, int, A&& ...a)
+    -> decltype(std::is_convertible<
+        decltype(c(a...)), R>::value ||
+            std::is_same<R, void>::value,
+                std::true_type());
+
+template<class R, class C, class ...A>
+std::false_type
+is_invocable_test(C&& c, long, A&& ...a);
+
+/** Metafunction returns `true` if F callable as R(A...)
+
+    Example:
+
+    @code
+        is_invocable<T, void(std::string)>
+    @endcode
+*/
+/** @{ */
+template<class C, class F>
+struct is_invocable
+    : std::false_type
+{
+};
+
+template<class C, class R, class ...A>
+struct is_invocable<C, R(A...)>
+    : decltype(is_invocable_test<R>(
+        std::declval<C>(), 1, std::declval<A>()...))
+{
+};
+/** @} */
+
 } // detail
 } // beast
 

include/beast/core/handler_concepts.hpp

@@ -9,7 +9,7 @@
 #define BEAST_HANDLER_CONCEPTS_HPP
 
 #include <beast/config.hpp>
-#include <beast/core/detail/is_call_possible.hpp>
+#include <beast/core/detail/type_traits.hpp>
 #include <type_traits>
 
 namespace beast {
@@ -21,7 +21,7 @@ using is_CompletionHandler = std::integral_constant<bool, ...>;
 #else
 using is_CompletionHandler = std::integral_constant<bool,
     std::is_copy_constructible<typename std::decay<T>::type>::value &&
-        detail::is_call_possible<T, Signature>::value>;
+        detail::is_invocable<T, Signature>::value>;
 #endif
 } // beast
 

include/beast/websocket/detail/type_traits.hpp

@@ -9,7 +9,7 @@
 #define BEAST_WEBSOCKET_DETAIL_TYPE_TRAITS_HPP
 
 #include <beast/websocket/rfc6455.hpp>
-#include <beast/core/detail/is_call_possible.hpp>
+#include <beast/core/detail/type_traits.hpp>
 
 namespace beast {
 namespace websocket {
@@ -17,12 +17,12 @@ namespace detail {
 
 template<class F>
 using is_RequestDecorator =
-    typename beast::detail::is_call_possible<F,
+    typename beast::detail::is_invocable<F,
         void(request_type&)>::type;
 
 template<class F>
 using is_ResponseDecorator =
-    typename beast::detail::is_call_possible<F,
+    typename beast::detail::is_invocable<F,
         void(response_type&)>::type;
 
 } // detail