synth-three-way/synth-three-way-result are widely used in the standard library, but currently they are exposition-only and don't have standard names. They seem useful when users want to adapt 3rd party types without operator<=> for their libraries with operator<=> provided - like what the standard library does.

Is such motivation discouraged? If no, it seems better to me to standardize these utilities.


Thanks,
F.v.S.