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Diffstat (limited to 'src/strings/clone.go')
-rw-r--r-- | src/strings/clone.go | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/src/strings/clone.go b/src/strings/clone.go new file mode 100644 index 0000000..d14df11 --- /dev/null +++ b/src/strings/clone.go @@ -0,0 +1,28 @@ +// 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. + +package strings + +import ( + "unsafe" +) + +// Clone returns a fresh copy of s. +// It guarantees to make a copy of s into a new allocation, +// which can be important when retaining only a small substring +// of a much larger string. Using Clone can help such programs +// use less memory. Of course, since using Clone makes a copy, +// overuse of Clone can make programs use more memory. +// Clone should typically be used only rarely, and only when +// profiling indicates that it is needed. +// For strings of length zero the string "" will be returned +// and no allocation is made. +func Clone(s string) string { + if len(s) == 0 { + return "" + } + b := make([]byte, len(s)) + copy(b, s) + return unsafe.String(&b[0], len(b)) +} |