al_get_num_audio_output_devices - Allegro 5 API

       Get the number of available audio output devices on the system.

       al_get_num_audio_output_devices - Allegro 5 API

       5.2.8

       return -1 for unsupported drivers.

Allegro reference manual                                                al_get_num_audio_output_devices(3alleg5)

              #include <allegro5/allegro_audio.h>

              int al_get_num_audio_output_devices()