fix adapt_type<...>::as<...> syntax

Signed-off-by: William Woodall <william@osrfoundation.org>
ros2 · Apr 29, 2021 · 70b7c17 · 70b7c17
1 parent c80d285
commit 70b7c17
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Showing 3 changed files with 20 additions and 11 deletions.
diff --git a/rclcpp/include/rclcpp/type_adapter.hpp b/rclcpp/include/rclcpp/type_adapter.hpp
@@ -116,17 +116,29 @@ struct is_type_adapter<TypeAdapter<Ts...>>: std::true_type {};
 template<typename T>
 struct TypeAdapter<T, void, std::enable_if_t<is_type_adapter<T>::value>>: T {};
 
+namespace detail
+{
+
+template<typename CustomType, typename ROSMessageType>
+struct assert_type_pair_is_specialized_type_adapter
+{
+  using type_adapter = TypeAdapter<CustomType, ROSMessageType>;
+  static_assert(
+    type_adapter::is_specialized::value,
+    "No type adapter for this custom type/ros message type pair");
+};
+
+}  // detail
+
 /// Template metafunction that can make the type being adapted explicit.
 template<typename CustomType>
 struct adapt_type
 {
   template<typename ROSMessageType>
-  struct as : TypeAdapter<CustomType, ROSMessageType>
-  {
-    static_assert(
-      TypeAdapter<CustomType, ROSMessageType>::is_specialized::value,
-      "No type adapter for this custom type/ros message type pair");
-  };
+  using as = typename ::rclcpp::detail::assert_type_pair_is_specialized_type_adapter<
+    CustomType,
+    ROSMessageType
+    >::type_adapter;
 };
 
 /// Implicit type adapter used as a short hand way to create something with just the custom type.

diff --git a/rclcpp/test/rclcpp/test_publisher_with_type_adapter.cpp b/rclcpp/test/rclcpp/test_publisher_with_type_adapter.cpp
@@ -156,13 +156,11 @@ TEST_F(TestPublisher, various_creation_signatures) {
       auto publisher = node->create_publisher<StringTypeAdapter>("topic", 42);
       (void)publisher;
     }
-    /* TODO(audrow) Enable this test once the adapt_type<>::as<> syntax is supported
     {
       using StringTypeAdapter = rclcpp::adapt_type<std::string>::as<rclcpp::msg::String>;
       auto publisher = node->create_publisher<StringTypeAdapter>("topic", 42);
       (void)publisher;
     }
-    */
   }
 }
 

diff --git a/rclcpp/test/rclcpp/test_subscription_with_type_adapter.cpp b/rclcpp/test/rclcpp/test_subscription_with_type_adapter.cpp
@@ -139,13 +139,12 @@ TEST_F(TestSubscription, various_creation_signatures) {
       node->create_subscription<StringTypeAdapter>("topic", 42, [](const std::string &) {});
     (void)sub;
   }
-  /* TODO(audrow) Enable this test once the adapt_type<>::as<> syntax is supported
   {
     using StringTypeAdapter = rclcpp::adapt_type<std::string>::as<rclcpp::msg::String>;
-    auto sub = node->create_subscription<StringTypeAdapter>("topic", 42, [](const std::string &) {});
+    auto sub =
+      node->create_subscription<StringTypeAdapter>("topic", 42, [](const std::string &) {});
     (void)sub;
   }
-  */
 }
 
 /*