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![Keith Randall](/assets/img/avatar_default.png)
We grow the backing store on append by 2x for small sizes and 1.25x for large sizes. The threshold we use for picking the growth factor used to depend on the old length, not the old capacity. That's kind of unfortunate, because then doing append(s, 0, 0) and append(append(s, 0), 0) do different things. (If s has one more spot available, then the former expression chooses its growth based on len(s) and the latter on len(s)+1.) If we instead use the old capacity, we get more consistent behavior. (Both expressions use len(s)+1 == cap(s) to decide.) Fixes #41239 Change-Id: I40686471d256edd72ec92aef973a89b52e235d4b Reviewed-on: https://go-review.googlesource.com/c/go/+/257338 Trust: Keith Randall <khr@golang.org> Trust: Josh Bleecher Snyder <josharian@gmail.com> Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
20 lines
393 B
Go
20 lines
393 B
Go
// run
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// Copyright 2020 The Go Authors. All rights reserved. Use of this
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// source code is governed by a BSD-style license that can be found in
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// the LICENSE file.
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package main
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import "fmt"
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func main() {
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const N = 1024
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var a [N]int
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x := cap(append(a[:N-1:N], 9, 9))
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y := cap(append(a[:N:N], 9))
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if x != y {
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panic(fmt.Sprintf("different capacity on append: %d vs %d", x, y))
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}
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}
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