A string of bytes that uniquely identifies this device.
If the same physical device supports both input and output, that makes
one SoundIoDevice for the input and one SoundIoDevice for the output.
In this case, the id of each SoundIoDevice will be the same, and
SoundIoDevice::aim will be different. Additionally, if the device
supports raw mode, there may be up to four devices with the same id:
one for each value of SoundIoDevice::is_raw and one for each value of
SoundIoDevice::aim.
A string of bytes that uniquely identifies this device.
If the same physical device supports both input and output, that makes one SoundIoDevice for the input and one SoundIoDevice for the output. In this case, the id of each SoundIoDevice will be the same, and SoundIoDevice::aim will be different. Additionally, if the device supports raw mode, there may be up to four devices with the same id: one for each value of SoundIoDevice::is_raw and one for each value of SoundIoDevice::aim.