Memory allocator for ROS2 messages?

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RCL has allocators to have custom memory management, that are taken from rcutils. Tests while doing my Ada binding show that this works nicely. I'm now trying to understand where a message allocator is configured. For example, in the rosidl-generated bool__functions.h there is:

bool std_msgs__msg__Bool__Array__init(std_msgs__msg__Bool__Array * array, size_t size);

and in general any array message is dynamically allocated (I think). I'm trying to ascertain what I should add to my binding to also provide allocators for messages. Thanks for any pointers.