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git.proxmox.com Git - rustc.git/blob - src/llvm/include/llvm/Support/SaveAndRestore.h
1 //===-- SaveAndRestore.h - Utility -------------------------------*- C++ -*-=//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file provides utility classes that uses RAII to save and restore
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_ADT_SAVERESTORE
16 #define LLVM_ADT_SAVERESTORE
20 // SaveAndRestore - A utility class that uses RAII to save and restore
21 // the value of a variable.
23 struct SaveAndRestore
{
24 SaveAndRestore(T
& x
) : X(x
), old_value(x
) {}
25 SaveAndRestore(T
& x
, const T
&new_value
) : X(x
), old_value(x
) {
28 ~SaveAndRestore() { X
= old_value
; }
29 T
get() { return old_value
; }
35 // SaveOr - Similar to SaveAndRestore. Operates only on bools; the old
36 // value of a variable is saved, and during the dstor the old value is
37 // or'ed with the new value.
39 SaveOr(bool& x
) : X(x
), old_value(x
) { x
= false; }
40 ~SaveOr() { X
|= old_value
; }