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// Copyright 2017 The Abseil Authors.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//      https://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#ifndef ABSL_BASE_INTERNAL_ERRNO_SAVER_H_

#define ABSL_BASE_INTERNAL_ERRNO_SAVER_H_

#include <cerrno>

#include "absl/base/config.h"

namespace absl {

ABSL_NAMESPACE_BEGIN

namespace base_internal {

// `ErrnoSaver` captures the value of `errno` upon construction and restores it

// upon deletion.  It is used in low-level code and must be super fast.  Do not

// add instrumentation, even in debug modes.

class ErrnoSaver {

 public:

  ErrnoSaver() : saved_errno_(errno) {}

  ~ErrnoSaver() { errno = saved_errno_; }

  int operator()() const { return saved_errno_; }

 private:

  const int saved_errno_;

};

}  // namespace base_internal

ABSL_NAMESPACE_END

}  // namespace absl

#endif  // ABSL_BASE_INTERNAL_ERRNO_SAVER_H_