switch v := p.arg.(type) {
			case error:
				handled = true
				defer p.catchPanic(p.arg, verb, "Error")
				p.fmtString(v.Error(), verb)
				return

			case Stringer:
				handled = true
				defer p.catchPanic(p.arg, verb, "String")
				p.fmtString(v.String(), verb)
				return
			}
		}
	}
	return false
}

func (p *pp) printArg(arg any, verb rune) {
	p.arg = arg