switch demanglerMode {
	case "": // demangled, simplified: no parameters, no templates, no return type
		return []demangle.Option{demangle.NoParams, demangle.NoEnclosingParams, demangle.NoTemplateParams}
	case "templates": // demangled, simplified: no parameters, no return type
		return []demangle.Option{demangle.NoParams, demangle.NoEnclosingParams}
	case "full":
		return []demangle.Option{demangle.NoClones}
	case "none": // no demangling

	}

	params := sig.Params()
	nparams := params.Len() // variadic => nonzero

	args := params.At(nparams - 1)
	iface, ok := args.Type().(*types.Slice).Elem().(*types.Interface)
	if !ok || !iface.Empty() {
		return nil // final (args) param is not ...interface{}
	}

	// Is second last param 'format string'?
	var format *types.Var
	if nparams >= 2 {