Proposal Details

Looks at this program:
playground

func x[A, B any](f func(A) B) func[S ~[]A](s S) []B {
	return nil
}

The go compiler raise error: function type must have no type parameters.

This lead to we can't write higher order function which takes type parameter.

In the above example, we can't make the return function take a slice that underlying type is ~[]E.

I don't want to put the type parameters into the declaration of function x, because S depends on the return function, not the function x.

Also declaring it in x forces me to specify the type parameters when calling x instead of deriving them automatically.