// errorcheck // Copyright 2019 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. // This code was incorrectly accepted by gccgo. package main type N string type M string const B N = "B" const C M = "C" func main() { q := B + C // ERROR "mismatched types|incompatible types" println(q) }