coreaudio_sys::audio_unit::HostCallback_GetMusicalTimeLocation

type HostCallback_GetMusicalTimeLocation = Option<extern fn(inHostUserData: *mut c_void, outDeltaSampleOffsetToNextBeat: *mut UInt32, outTimeSig_Numerator: *mut Float32, outTimeSig_Denominator: *mut UInt32, outCurrentMeasureDownBeat: *mut Float64) -> OSStatus>;