static_buffer coverage

test/core/async_result.cpp

@@ -7,3 +7,32 @@
 
 // Test that header file is self-contained.
 #include <beast/core/async_result.hpp>
+
+#include <beast/core/error.hpp>
+#include <beast/core/type_traits.hpp>
+#include <cstdlib>
+
+namespace beast {
+namespace {
+
+struct handler
+{
+    void operator()(beast::error_code, std::size_t) const;
+};
+
+static_assert(detail::is_invocable<
+    typename async_result<handler, void(error_code, std::size_t)>::completion_handler_type,
+    void(error_code, std::size_t)>::value, "");
+
+static_assert(std::is_same<void,
+    typename async_result<handler, void(error_code, std::size_t)>::return_type>::value, "");
+
+static_assert(std::is_constructible<
+    async_result<handler,
+        void(error_code, std::size_t)>,
+    typename async_result<handler,
+        void(error_code, std::size_t)
+            >::completion_handler_type&>::value, "");
+
+} // (anon-ns)
+} // beast