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// 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.
//go:build !race
package test
import (
"internal/testenv"
"testing"
)
func TestAppendOfMake(t *testing.T) {
testenv.SkipIfOptimizationOff(t)
for n := 32; n < 33; n++ { // avoid stack allocation of make()
b := make([]byte, n)
f := func() {
b = append(b[:0], make([]byte, n)...)
}
if n := testing.AllocsPerRun(10, f); n > 0 {
t.Errorf("got %f allocs, want 0", n)
}
type S []byte
s := make(S, n)
g := func() {
s = append(s[:0], make(S, n)...)
}
if n := testing.AllocsPerRun(10, g); n > 0 {
t.Errorf("got %f allocs, want 0", n)
}
h := func() {
s = append(s[:0], make([]byte, n)...)
}
if n := testing.AllocsPerRun(10, h); n > 0 {
t.Errorf("got %f allocs, want 0", n)
}
i := func() {
b = append(b[:0], make(S, n)...)
}
if n := testing.AllocsPerRun(10, i); n > 0 {
t.Errorf("got %f allocs, want 0", n)
}
}
}
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