src/Utils/scope_exit_noexcept.h

   1 // TortoiseGit - a Windows shell extension for easy version control
   2
   3 // Copyright (C) 2015 - TortoiseGit
   4
   5 // based on public domain implementation:
   6 // https://codeproject.cachefly.net/Articles/124130/Simple-Look-Scope-Guard-for-Visual-C
   7
   8 // This program is free software; you can redistribute it and/or
   9 // modify it under the terms of the GNU General Public License
  10 // as published by the Free Software Foundation; either version 2
  11 // of the License, or (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software Foundation,
  20 // 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21 //
  22
  23 #pragma once
  24
  25 template <typename D>
  26 class scope_exit_t
  27 {
  28 public:
  29         explicit scope_exit_t(D&& f) : func(f) {}
  30         scope_exit_t(scope_exit_t&& s) : func(s.func) {}
  31
  32         ~scope_exit_t() { func(); }
  33
  34 private:
  35         // Prohibit construction from lvalues.
  36         scope_exit_t(D&);
  37
  38         // Prohibit copying.
  39         scope_exit_t(const scope_exit_t&);
  40         scope_exit_t& operator=(const scope_exit_t&);
  41
  42         // Prohibit new/delete.
  43         void* operator new(size_t) = delete;
  44         void* operator new[](size_t) = delete;
  45         void operator delete(void*) = delete;
  46         void operator delete[](void*) = delete;
  47
  48         const D func;
  49 };
  50
  51 struct scope_exit_helper
  52 {
  53         template <typename D>
  54         scope_exit_t<D> operator<< (D&& f) {
  55                 return scope_exit_t<D>(std::forward<D>(f));
  56         }
  57 };
  58
  59 #define SCOPE_EXIT_CAT2(x, y) x##y
  60 #define SCOPE_EXIT_CAT1(x, y) SCOPE_EXIT_CAT2(x, y)
  61 #define SCOPE_EXIT auto SCOPE_EXIT_CAT1(scope_exit_, __COUNTER__) \
  62         = scope_exit_helper() << [&]