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       1             : //===- llvm/ADT/ScopeExit.h - Execute code at scope exit --------*- C++ -*-===//
       2             : //
       3             : //                     The LLVM Compiler Infrastructure
       4             : //
       5             : // This file is distributed under the University of Illinois Open Source
       6             : // License. See LICENSE.TXT for details.
       7             : //
       8             : //===----------------------------------------------------------------------===//
       9             : //
      10             : // This file defines the make_scope_exit function, which executes user-defined
      11             : // cleanup logic at scope exit.
      12             : //
      13             : //===----------------------------------------------------------------------===//
      14             : 
      15             : #ifndef LLVM_ADT_SCOPE_EXIT_H
      16             : #define LLVM_ADT_SCOPE_EXIT_H
      17             : 
      18             : #include "llvm/Support/Compiler.h"
      19             : 
      20             : #include <type_traits>
      21             : #include <utility>
      22             : 
      23             : namespace llvm {
      24             : namespace detail {
      25             : 
      26             : template <typename Callable> class scope_exit {
      27             :   Callable ExitFunction;
      28             :   bool Engaged = true; // False once moved-from or release()d.
      29             : 
      30             : public:
      31             :   template <typename Fp>
      32       35221 :   explicit scope_exit(Fp &&F) : ExitFunction(std::forward<Fp>(F)) {}
      33             : 
      34         238 :   scope_exit(scope_exit &&Rhs)
      35         238 :       : ExitFunction(std::move(Rhs.ExitFunction)), Engaged(Rhs.Engaged) {
      36             :     Rhs.release();
      37             :   }
      38             :   scope_exit(const scope_exit &) = delete;
      39             :   scope_exit &operator=(scope_exit &&) = delete;
      40             :   scope_exit &operator=(const scope_exit &) = delete;
      41             : 
      42         119 :   void release() { Engaged = false; }
      43             : 
      44         373 :   ~scope_exit() {
      45       35459 :     if (Engaged)
      46       35205 :       ExitFunction();
      47         373 :   }
      48             : };
      49             : 
      50             : } // end namespace detail
      51             : 
      52             : // Keeps the callable object that is passed in, and execute it at the
      53             : // destruction of the returned object (usually at the scope exit where the
      54             : // returned object is kept).
      55             : //
      56             : // Interface is specified by p0052r2.
      57             : template <typename Callable>
      58             : LLVM_NODISCARD detail::scope_exit<typename std::decay<Callable>::type>
      59           0 : make_scope_exit(Callable &&F) {
      60             :   return detail::scope_exit<typename std::decay<Callable>::type>(
      61           0 :       std::forward<Callable>(F));
      62             : }
      63             : 
      64             : } // end namespace llvm
      65             : 
      66             : #endif