// 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.
// Test for slice to array conversion introduced in go1.20
// See: https://tip.golang.org/ref/spec#Conversions_from_slice_to_array_pointer
package main
func main() {
s := make([]byte, 3, 4)
s[0], s[1], s[2] = 2, 3, 5
a := ([2]byte)(s)
s[0] = 7
if a != [2]byte{2, 3} {
panic("converted from non-nil slice to array")
}
{
var s []int
a := ([0]int)(s)
if a != [0]int{} {
panic("zero len array is not equal")
}
}
if emptyToEmptyDoesNotPanic() {
panic("no panic expected from emptyToEmptyDoesNotPanic()")
}
if !threeToFourDoesPanic() {
panic("panic expected from threeToFourDoesPanic()")
}
if !fourPanicsWhileOneDoesNot[[4]int]() {
panic("panic expected from fourPanicsWhileOneDoesNot[[4]int]()")
}
if fourPanicsWhileOneDoesNot[[1]int]() {
panic("no panic expected from fourPanicsWhileOneDoesNot[[1]int]()")
}
if !fourPanicsWhileZeroDoesNot[[4]int]() {
panic("panic expected from fourPanicsWhileZeroDoesNot[[4]int]()")
}
if fourPanicsWhileZeroDoesNot[[0]int]() {
panic("no panic expected from fourPanicsWhileZeroDoesNot[[0]int]()")
}
}
func emptyToEmptyDoesNotPanic() (raised bool) {
defer func() {
if e := recover(); e != nil {
raised = true
}
}()
var s []int
_ = ([0]int)(s)
return false
}
func threeToFourDoesPanic() (raised bool) {
defer func() {
if e := recover(); e != nil {
raised = true
}
}()
s := make([]int, 3, 5)
_ = ([4]int)(s)
return false
}
func fourPanicsWhileOneDoesNot[T [1]int | [4]int]() (raised bool) {
defer func() {
if e := recover(); e != nil {
raised = true
}
}()
s := make([]int, 3, 5)
_ = T(s)
return false
}
func fourPanicsWhileZeroDoesNot[T [0]int | [4]int]() (raised bool) {
defer func() {
if e := recover(); e != nil {
raised = true
}
}()
var s []int
_ = T(s)
return false
}