src/internal/types/testdata/check/typeinference.go

// 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]
}