Included get_available_rmw_implementations

Signed-off-by: ahcorde <ahcorde@gmail.com>

rclpy/rclpy/utilities.py

@@ -18,6 +18,8 @@
 from rclpy.constants import S_TO_NS
 from rclpy.context import Context
 
+import ament_index_python
+
 g_default_context = None
 g_context_lock = threading.Lock()
 
@@ -68,6 +70,12 @@ def get_rmw_implementation_identifier():
     return rclpy_implementation.rclpy_get_rmw_implementation_identifier()
 
 
+def get_available_rmw_implementations():
+    """Return the set of all available RMW implementations as registered in the ament index."""
+    rmw_implementations = ament_index_python.get_resources('rmw_typesupport')
+    return {name for name in rmw_implementations if name != 'rmw_implementation'}
+
+
 def timeout_sec_to_nsec(timeout_sec):
     """
     Convert timeout in seconds to rcl compatible timeout in nanoseconds.