1 files changed, 43 insertions, 0 deletions
diff --git a/test/typeparam/tparam1.go b/test/typeparam/tparam1.go
new file mode 100644
index 0000000..a05f542
--- /dev/null
+++ b/test/typeparam/tparam1.go
@@ -0,0 +1,43 @@
+// errorcheck
+
+// Copyright 2020 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.
+
+// Basic type parameter list type-checking (not syntax) errors.
+
+package tparam1
+
+// The predeclared identifier "any" may be used in place of interface{}.
+var _ any
+
+func _(_ any)
+
+type _[_ any] struct{}
+
+const N = 10
+
+type (
+	_                     []struct{}  // slice
+	_                     [N]struct{} // array
+	_[T any]              struct{}
+	_[T, T any]           struct{} // ERROR "T redeclared"
+	_[T1, T2 any, T3 any] struct{}
+)
+
+func _[T any]()             {}
+func _[T, T any]()          {} // ERROR "T redeclared"
+func _[T1, T2 any](x T1) T2 { panic(0) }
+
+// Type parameters are visible from opening [ to end of function.
+type C interface{}
+
+func _[T interface{}]()        {}
+func _[T C]()                  {}
+func _[T struct{}]()           {} // ok if #48424 is accepted
+func _[T interface{ m() T }]() {}
+func _[T1 interface{ m() T2 }, T2 interface{ m() T1 }]() {
+	var _ T1
+}
+
+// TODO(gri) expand this