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// run
// Copyright 2017 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.
// Issue 21687: cmd/compile evaluates x twice in "x op= y", which was
// detectable if evaluating y affects x.
package main
func ptrs() (int, int) {
one := 1
two := 2
x := &one
*x += func() int {
x = &two
return 0
}()
return one, two
}
func slices() (int, int) {
one := []int{1}
two := []int{2}
x := one
x[0] += func() int {
x = two
return 0
}()
return one[0], two[0]
}
func maps() (int, int) {
one := map[int]int{0: 1}
two := map[int]int{0: 2}
x := one
x[0] += func() int {
x = two
return 0
}()
return one[0], two[0]
}
var tests = [...]func() (int, int){
ptrs,
slices,
maps,
}
func main() {
bad := 0
for i, f := range tests {
if a, b := f(); a+b != 3 {
println(i, a, b)
bad++
}
}
if bad != 0 {
panic(bad)
}
}
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