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//===-- SaveAndRestore.h - Utility -------------------------------*- C++ -*-=//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file provides utility classes that uses RAII to save and restore
// values.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_SAVEANDRESTORE_H
#define LLVM_SUPPORT_SAVEANDRESTORE_H
namespace llvm {
// SaveAndRestore - A utility class that uses RAII to save and restore
// the value of a variable.
template<typename T>
struct SaveAndRestore {
SaveAndRestore(T& x) : X(x), old_value(x) {}
SaveAndRestore(T& x, const T &new_value) : X(x), old_value(x) {
X = new_value;
}
~SaveAndRestore() { X = old_value; }
T get() { return old_value; }
private:
T& X;
T old_value;
};
// SaveOr - Similar to SaveAndRestore. Operates only on bools; the old
// value of a variable is saved, and during the dstor the old value is
// or'ed with the new value.
struct SaveOr {
SaveOr(bool& x) : X(x), old_value(x) { x = false; }
~SaveOr() { X |= old_value; }
private:
bool& X;
const bool old_value;
};
}
#endif
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