//===- llvm/ADT/ScopeExit.h - Execute code at scope exit --------*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

//

// This file defines the make_scope_exit function, which executes user-defined

// cleanup logic at scope exit.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_ADT_SCOPE_EXIT_H

#define LLVM_ADT_SCOPE_EXIT_H

#include "llvm/Support/Compiler.h"

#include <type_traits>

#include <utility>

namespace llvm {

namespace detail {

template <typename Callable> class scope_exit {

  Callable ExitFunction;

  bool Engaged = true; // False once moved-from or release()d.

public:

  template <typename Fp>

  explicit scope_exit(Fp &&F) : ExitFunction(std::forward<Fp>(F)) {}

  scope_exit(scope_exit &&Rhs)

      : ExitFunction(std::move(Rhs.ExitFunction)), Engaged(Rhs.Engaged) {

    Rhs.release();

  }

  scope_exit(const scope_exit &) = delete;

  scope_exit &operator=(scope_exit &&) = delete;

  scope_exit &operator=(const scope_exit &) = delete;

  void release() { Engaged = false; }

  ~scope_exit() {

    if (Engaged)

      ExitFunction();

  }

};

} // end namespace detail

// Keeps the callable object that is passed in, and execute it at the

// destruction of the returned object (usually at the scope exit where the

// returned object is kept).

//

// Interface is specified by p0052r2.

template <typename Callable>

LLVM_NODISCARD detail::scope_exit<typename std::decay<Callable>::type>

make_scope_exit(Callable &&F) {

  return detail::scope_exit<typename std::decay<Callable>::type>(

      std::forward<Callable>(F));

}

} // end namespace llvm

#endif