src/libs/common/SmartPtr.h

   1 //                                                      -*- C++ -*-
   2 // This file is part of the aMule Project.
   3 //
   4 // Copyright (c) 2019 aMule Team ( admin@amule.org / http://www.amule.org )
   5 //
   6 // Any parts of this program derived from the xMule, lMule or eMule project,
   7 // or contributed by third-party developers are copyrighted by their
   8 // respective authors.
   9 //
  10 // This program is free software; you can redistribute it and/or modify
  11 // it under the terms of the GNU General Public License as published by
  12 // the Free Software Foundation; either version 2 of the License, or
  13 // (at your option) any later version.
  14 //
  15 // This program is distributed in the hope that it will be useful,
  16 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 // GNU General Public License for more details.
  19 //
  20 // You should have received a copy of the GNU General Public License
  21 // along with this program; if not, write to the Free Software
  22 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA
  23 //
  24
  25 #ifndef SMARTPTR_H
  26 #define SMARTPTR_H
  27
  28 // std::auto_ptr is deprecated in C++11 and removed in C++17. We should use
  29 // std::unique_ptr instead, which was introduced in C++11.
  30 //
  31 // Considering the above, we shall use std::unique_ptr if we're using C++11 or
  32 // a later standard, and std::auto_ptr otherwise.
  33
  34 #include <memory>
  35
  36 #if __cplusplus >= 201103L
  37
  38 // It seems like Apple has (or had, hopefully) a configuration where a new
  39 // clang compiler supporting C++11 is accompanied by an old c++ library not
  40 // supporting std::unique_ptr.
  41 // See https://stackoverflow.com/questions/31655462/no-type-named-unique-ptr-in-namespace-std-when-compiling-under-llvm-clang
  42 #       ifdef __clang__
  43 #               if __has_include(<forward_list>)
  44                         // either using libc++ or a libstdc++ that's
  45                         // new enough to have unique_ptr
  46 #                       define HAVE_UNIQUE_PTR 1
  47 #               endif
  48 #       else
  49                 // not clang, assume unique_ptr available
  50 #               define HAVE_UNIQUE_PTR 1
  51 #       endif
  52
  53 #endif
  54
  55 #ifdef HAVE_UNIQUE_PTR
  56 template<typename T> using CSmartPtr = std::unique_ptr<T>;
  57 #else
  58 #       define CSmartPtr std::auto_ptr
  59 #       ifndef nullptr
  60 #               define nullptr   NULL
  61 #       endif
  62 #endif
  63
  64 #undef HAVE_UNIQUE_PTR
  65
  66 #endif /* SMARTPTR_H */