// errorcheck // Copyright 2018 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package main type Stringer interface { String() string } func main() { var e interface{} switch e := e.(type) { case G: // ERROR "undefined: G|undefined type .*G" e.M() // ok: this error should be ignored because the case failed its typecheck case E: // ERROR "undefined: E|undefined type .*E" e.D() // ok: this error should be ignored because the case failed its typecheck case Stringer: // ok: this error should not be ignored to prove that passing legs aren't left out _ = e.(T) // ERROR "undefined: T|undefined type .*T" } }