MidiInProc typedef Null safety

MidiInProc = Void Function(HMIDIIN hMidiIn, UINT wMsg, DWORD_PTR dwInstance, DWORD_PTR dwParam1, DWORD_PTR dwParam2)

Application-defined callback function for handling incoming MIDI messages. MidiInProc is a placeholder for the application-supplied function name. The address of this function can be specified in the callback-address parameter of the midiInOpen function.

Implementation

typedef MidiInProc = Void Function(HMIDIIN hMidiIn, UINT wMsg,
    DWORD_PTR dwInstance, DWORD_PTR dwParam1, DWORD_PTR dwParam2);