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Diffstat (limited to 'test/typeswitch3.go')
-rw-r--r-- | test/typeswitch3.go | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/test/typeswitch3.go b/test/typeswitch3.go new file mode 100644 index 0000000..2e144d8 --- /dev/null +++ b/test/typeswitch3.go @@ -0,0 +1,56 @@ +// errorcheck + +// Copyright 2011 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. + +// Verify that erroneous type switches are caught by the compiler. +// Issue 2700, among other things. +// Does not compile. + +package main + +import ( + "io" +) + +type I interface { + M() +} + +func main() { + var x I + switch x.(type) { + case string: // ERROR "impossible" + println("FAIL") + } + + // Issue 2700: if the case type is an interface, nothing is impossible + + var r io.Reader + + _, _ = r.(io.Writer) + + switch r.(type) { + case io.Writer: + } + + // Issue 2827. + switch _ := r.(type) { // ERROR "invalid variable name _|no new variables?" + } +} + +func noninterface() { + var i int + switch i.(type) { // ERROR "cannot type switch on non-interface value|not an interface" + case string: + case int: + } + + type S struct { + name string + } + var s S + switch s.(type) { // ERROR "cannot type switch on non-interface value|not an interface" + } +} |