1 files changed, 48 insertions, 0 deletions
diff --git a/test/typeparam/typeswitch3.go b/test/typeparam/typeswitch3.go
new file mode 100644
index 0000000..b84fdd0
--- /dev/null
+++ b/test/typeparam/typeswitch3.go
@@ -0,0 +1,48 @@
+// run
+
+// Copyright 2021 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 I interface{ foo() int }
+type J interface {
+	I
+	bar()
+}
+
+type myint int
+
+func (x myint) foo() int { return int(x) }
+
+type myfloat float64
+
+func (x myfloat) foo() int { return int(x) }
+
+type myint32 int32
+
+func (x myint32) foo() int { return int(x) }
+func (x myint32) bar()     {}
+
+func f[T I](i I) {
+	switch x := i.(type) {
+	case T:
+		println("T", x.foo())
+	case myint:
+		println("myint", x.foo())
+	default:
+		println("other", x.foo())
+	}
+}
+func main() {
+	f[myfloat](myint(6))
+	f[myfloat](myfloat(7))
+	f[myfloat](myint32(8))
+	f[myint32](myint32(8))
+	f[myint32](myfloat(7))
+	f[myint](myint32(9))
+	f[I](myint(10))
+	f[J](myint(11))
+	f[J](myint32(12))
+}