golang issue20174 代码
文件路径：/test/fixedbugs/issue20174.go
/ compile -c=2
/ Copyright 2017 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.
/ Issue 20174: failure to typecheck contents of *T in the frontend.
package p
func f() {
_ = (*interface{})(nil) / interface{} here used to not have its width calculated going into backend
select {
case _ = <-make(chan interface {
M()
}, 1):
}
}