src/internal/types/testdata/fixedbugs/issue51472.go

// Copyright 2022 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 p

func _[T comparable](x T) {
        _ = x == x
}

func _[T interface{interface{comparable}}](x T) {
        _ = x == x
}

func _[T interface{comparable; interface{comparable}}](x T) {
        _ = x == x
}

func _[T interface{comparable; ~int}](x T) {
        _ = x == x
}

func _[T interface{comparable; ~[]byte}](x T) {
        _ = x /* ERROR "empty type set" */ == x
}

// TODO(gri) The error message here should be better. See issue #51525.
func _[T interface{comparable; ~int; ~string}](x T) {
        _ = x /* ERROR "empty type set" */ == x
}

// TODO(gri) The error message here should be better. See issue #51525.
func _[T interface{~int; ~string}](x T) {
        _ = x /* ERROR "empty type set" */ == x
}

func _[T interface{comparable; interface{~int}; interface{int|float64}}](x T) {
        _ = x == x
}

func _[T interface{interface{comparable; ~int}; interface{~float64; comparable; m()}}](x T) {
        _ = x /* ERROR "empty type set" */ == x
}

// test case from issue

func f[T interface{comparable; []byte|string}](x T) {
        _ = x == x
}

func _(s []byte) {
	f /* ERROR "T (type []byte) does not satisfy interface{comparable; []byte | string}" */ (s) // TODO(gri) better error message (T's type set only contains string!)
        _ = f[[ /* ERROR "does not satisfy" */ ]byte]
}