blob: ff2d9b55ccdaebee5af5677c8db45581b6a2e3ef [file] [log] [blame]
// 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 for slice to array pointer conversion introduced in go1.17
// See: https://tip.golang.org/ref/spec#Conversions_from_slice_to_array_pointer
package main
func main() {
s := make([]byte, 2, 4)
if s0 := (*[0]byte)(s); s0 == nil {
panic("converted from non-nil slice result in nil array pointer")
}
if s2 := (*[2]byte)(s); &s2[0] != &s[0] {
panic("the converted array is not slice underlying array")
}
wantPanic(
func() {
_ = (*[4]byte)(s) // panics: len([4]byte) > len(s)
},
"runtime error: array length is greater than slice length",
)
var t []string
if t0 := (*[0]string)(t); t0 != nil {
panic("nil slice converted to *[0]byte should be nil")
}
wantPanic(
func() {
_ = (*[1]string)(t) // panics: len([1]string) > len(t)
},
"runtime error: array length is greater than slice length",
)
}
type arr [2]int
func f() {
s := []int{1, 2, 3, 4}
_ = *(*arr)(s)
}
func wantPanic(fn func(), s string) {
defer func() {
err := recover()
if err == nil {
panic("expected panic")
}
if got := err.(error).Error(); got != s {
panic("expected panic " + s + " got " + got)
}
}()
fn()
}