Composes a message from arguments. Anything that was
previously written to the composer will be cleared.
If the buffer reaches capacity before the composition
can be completed, the composer will enact the selected
overflow policy.
The callback policy is special, in that it will retry
the failed composition after the callback has been
called. This is to allow callbacks to grow a composer as
needed. If the retry fails, the function exits.
Composes a message from arguments. Anything that was previously written to the composer will be cleared.
If the buffer reaches capacity before the composition can be completed, the composer will enact the selected overflow policy.
The callback policy is special, in that it will retry the failed composition after the callback has been called. This is to allow callbacks to grow a composer as needed. If the retry fails, the function exits.