Add functor at the front of this queue.
Add the specified functor at the front of this queue. Return 0 on success, and a non-zero value if enqueuing is disabled. The value of functor becomes unspecified but valid, and its allocator remains unchanged.
0 on success, and a non-zero value if enqueuing is disabled
| Name | Description |
|---|---|
| functor | job to enqueue at the front of this queue |