Add rmw_feature_supported()

Signed-off-by: Ivan Santiago Paunovic <ivanpauno@ekumenlabs.com>

rmw/include/rmw/features.h

@@ -0,0 +1,63 @@
+// Copyright 2022 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+
+#ifndef RMW__FEATURES_H_
+#define RMW__FEATURES_H_
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+#include <stdint.h>
+
+#include "rcutils/allocator.h"
+
+#include "rmw/macros.h"
+#include "rmw/types.h"
+#include "rmw/ret_types.h"
+#include "rmw/visibility_control.h"
+
+/// List of optional rmw features.
+/**
+ * Some of the features listed here might become mandatory in the feature, in which case all rmw
+ * implementations should return `true`.
+ *
+ * There might be some optional features that are not listed here, but the goal is to have all of
+ * them added.
+ */
+typedef enum rmw_feature_e
+{
+ /// `rmw_message_info_t.publication_sequence_number` is filled correctly
+ /// by the rmw implementation.
+ RMW_FEATURE_MESSAGE_INFO_PUBLICATION_SEQUENCE_NUMBER = 0,
+ /// `rmw_message_info_t.reception_sequence_number` is filled correctly
+ /// by the rmw implementation.
+ RMW_FEATURE_MESSAGE_INFO_RECEPTION_SEQUENCE_NUMBER = 1,
+} rmw_feature_t;
+
+/// Query if a feature is supported by the rmw implementation.
+/**
+ * \return `true` if the rmw implementation supports the feature, `false` if not.
+ */
+RMW_PUBLIC
+bool
+rmw_feature_supported(rmw_feature_t feature);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // RMW__FEATURES_H_