code: func (l Library) MakeFunction(name string) (Function, error) {
  	f := C.Library_MakeFunction(l.library, C.CString(name))
  	if f == nil {
  		return Function{}, fmt.Errorf("function %q not found", name)
  	}
  
  	return Function{f}, nil
  }
docs: // MakeFunction returns a pre-compiled, non-specialized function.
  //
  // Reference: https://developer.apple.com/documentation/metal/mtllibrary/1515524-makefunction.