"assignable to" type constraint for generic type parameters

Consider the following (playground):

import "fmt" type Gizmo string func (g Gizmo) String() string { return string(g) } func Convert(in []Gizmo) []fmt.Stringer { out := make([]fmt.Stringer, 0, len(in)) for _, v := range in { out = append(out, v) } return out }

Is there a way to turn Convert into a generic function like this (playground):

type AssignableTo[T any] interface { // magic goes here } func Convert[Out any, In AssignableTo[Out]](in []In) []Out { out := make([]Out, 0, len(in)) for _, v := range in { out = append(out, v) } return out }

I would like to be able to use the generic function for any assignable type, not just implemented interfaces. For example:

bidiChs := []chan Foo{/* ... */} sendChs := Convert[chan<- Foo](bidiChs)

(This is a re-ask because I chose the wrong question type with the new opinion-based question feature and don't see a way to fix it.)