I want to enforce copy function to extends original function. but the trick is – the order of params of fnGenerator is opposite.

Can it be done?

function fnGenerator<Original extends Copy, Copy extends Function>(copy:Copy,original:Original){}

function original(props:{a?:number,z:number}):number { return 2}
function copy(props:{a:number}):number { return 1}

fnGenerator(copy,original) // right now `original` has complicatione error instead of `copy`.