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![Keith Randall](/assets/img/avatar_default.png)
type I[T any] interface{} This is an interface, but it has a type parameter. We need to distinguish that from an interface that is not parameterized. That means when doing type substitution on an interface with parameters, we need to make a new one. Same for non-empty interfaces. Even if the type parameter is not used in any method, we sill need to make a new type. Similar case to tstruct, above. Change-Id: I23ad9f21d2c4ef675bf3f7d84899d9e4919d05e7 Reviewed-on: https://go-review.googlesource.com/c/go/+/344578 Trust: Keith Randall <khr@golang.org> Trust: Dan Scales <danscales@google.com> Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Dan Scales <danscales@google.com>
72 lines
1.3 KiB
Go
72 lines
1.3 KiB
Go
// run -gcflags=-G=3
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// Copyright 2021 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Make sure we handle instantiated empty interfaces.
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package main
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type E[T any] interface {
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}
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//go:noinline
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func f[T any](x E[T]) interface{} {
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return x
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}
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//go:noinline
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func g[T any](x interface{}) E[T] {
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return x
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}
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type I[T any] interface {
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foo()
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}
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type myint int
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func (x myint) foo() {}
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//go:noinline
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func h[T any](x I[T]) interface{ foo() } {
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return x
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}
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//go:noinline
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func i[T any](x interface{ foo() }) I[T] {
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return x
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}
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func main() {
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if f[int](1) != 1 {
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println("test 1 failed")
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}
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if f[int](2) != (interface{})(2) {
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println("test 2 failed")
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}
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if g[int](3) != 3 {
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println("test 3 failed")
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}
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if g[int](4) != (E[int])(4) {
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println("test 4 failed")
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}
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if h[int](myint(5)) != myint(5) {
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// TODO: disabled
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//println("test 5 failed")
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}
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if h[int](myint(6)) != interface{ foo() }(myint(6)) {
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// TODO: disabled
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//println("test 6 failed")
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}
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if i[int](myint(7)) != myint(7) {
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// TODO: This happens to work, but not for the right reasons.
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println("test 7 failed")
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}
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if i[int](myint(8)) != I[int](myint(8)) {
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// TODO: disabled
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//println("test 8 failed")
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}
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}
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