1 files changed, 49 insertions, 0 deletions
diff --git a/src/internal/types/testdata/check/typeinference.go b/src/internal/types/testdata/check/typeinference.go
new file mode 100644
index 0000000..28f3e28
--- /dev/null
+++ b/src/internal/types/testdata/check/typeinference.go
@@ -0,0 +1,49 @@
+// 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 typeInference
+
+// As of issue #51527, type-type inference has been disabled.
+
+// basic inference
+type Tb[P ~*Q, Q any] int
+func _() {
+	var x Tb /* ERROR got 1 arguments */ [*int]
+	var y Tb[*int, int]
+	x = y /* ERROR cannot use y .* in assignment */
+	_ = x
+}
+
+// recursive inference
+type Tr[A any, B *C, C *D, D *A] int
+func _() {
+	var x Tr /* ERROR got 1 arguments */ [string]
+	var y Tr[string, ***string, **string, *string]
+	var z Tr[int, ***int, **int, *int]
+	x = y /* ERROR cannot use y .* in assignment */
+	x = z // ERROR cannot use z .* as Tr
+	_ = x
+}
+
+// other patterns of inference
+type To0[A any, B []A] int
+type To1[A any, B struct{a A}] int
+type To2[A any, B [][]A] int
+type To3[A any, B [3]*A] int
+type To4[A any, B any, C struct{a A; b B}] int
+func _() {
+	var _ To0 /* ERROR got 1 arguments */ [int]
+	var _ To1 /* ERROR got 1 arguments */ [int]
+	var _ To2 /* ERROR got 1 arguments */ [int]
+	var _ To3 /* ERROR got 1 arguments */ [int]
+	var _ To4 /* ERROR got 2 arguments */ [int, string]
+}
+
+// failed inference
+type Tf0[A, B any] int
+type Tf1[A any, B ~struct{a A; c C}, C any] int
+func _() {
+	var _ Tf0 /* ERROR got 1 arguments but 2 type parameters */ [int]
+	var _ Tf1 /* ERROR got 1 arguments but 3 type parameters */ [int]
+}