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go/test/typeparam/ifaceconv.go
Matthew Dempsky 5355753009 [dev.typeparams] test/typeparam: gofmt -w
We don't usually reformat the test directory, but all of the files in
test/typeparam are syntactically valid. I suspect the misformattings
here are because developers aren't re-installing gofmt with
-tags=typeparams, not intentionally exercising non-standard
formatting.

Change-Id: I3767d480434c19225568f3c7d656dc8589197183
Reviewed-on: https://go-review.googlesource.com/c/go/+/338093
Trust: Matthew Dempsky <mdempsky@google.com>
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2021-07-28 21:40:40 +00:00

84 lines
1.7 KiB
Go

// run -gcflags=-G=3
// 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.
// Test that we can convert type parameters to both empty
// and nonempty interfaces, and named and nonnamed versions
// thereof.
package main
import "fmt"
type E interface{}
func f[T any](x T) interface{} {
var i interface{} = x
return i
}
func fs[T any](x T) interface{} {
y := []T{x}
var i interface{} = y
return i
}
func g[T any](x T) E {
var i E = x
return i
}
type C interface {
foo() int
}
type myInt int
func (x myInt) foo() int {
return int(x + 1)
}
func h[T C](x T) interface{ foo() int } {
var i interface{ foo() int } = x
return i
}
func i[T C](x T) C {
var i C = x // conversion in assignment
return i
}
func j[T C](t T) C {
return C(t) // explicit conversion
}
func js[T any](x T) interface{} {
y := []T{x}
return interface{}(y)
}
func main() {
if got, want := f[int](7), 7; got != want {
panic(fmt.Sprintf("got %d want %d", got, want))
}
if got, want := fs[int](7), []int{7}; got.([]int)[0] != want[0] {
panic(fmt.Sprintf("got %d want %d", got, want))
}
if got, want := g[int](7), 7; got != want {
panic(fmt.Sprintf("got %d want %d", got, want))
}
if got, want := h[myInt](7).foo(), 8; got != want {
panic(fmt.Sprintf("got %d want %d", got, want))
}
if got, want := i[myInt](7).foo(), 8; got != want {
panic(fmt.Sprintf("got %d want %d", got, want))
}
if got, want := j[myInt](7).foo(), 8; got != want {
panic(fmt.Sprintf("got %d want %d", got, want))
}
if got, want := js[int](7), []int{7}; got.([]int)[0] != want[0] {
panic(fmt.Sprintf("got %d want %d", got, want))
}
}