1 | /** @file
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2 | * innotek Portable Runtime - C++ Extensions: memory.
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3 | */
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4 |
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5 | /*
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6 | * Copyright (C) 2007 innotek GmbH
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7 | *
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8 | * This file is part of VirtualBox Open Source Edition (OSE), as
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9 | * available from http://www.virtualbox.org. This file is free software;
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10 | * you can redistribute it and/or modify it under the terms of the GNU
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11 | * General Public License as published by the Free Software Foundation,
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12 | * in version 2 as it comes in the "COPYING" file of the VirtualBox OSE
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13 | * distribution. VirtualBox OSE is distributed in the hope that it will
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14 | * be useful, but WITHOUT ANY WARRANTY of any kind.
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15 | */
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16 |
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17 | #ifndef ___iprt_memory___
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18 | #define ___iprt_memory___
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19 |
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20 | /** @defgroup grp_rt_cppx_memory innotek Portable Runtime C++ Extensions: memory
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21 | * @ingroup grp_rt_cppx
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22 | * @{
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23 | */
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24 |
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25 | #ifdef __cplusplus
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26 |
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27 | #include <memory> /* for auto_ptr */
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28 |
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29 | namespace cppx
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30 | {
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31 |
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32 | /**
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33 | * A simple std::auto_ptr extension that adds CopyConstructible and
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34 | * Assignable semantics.
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35 | *
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36 | * Instances of this class, when constructed from or assigned with instances
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37 | * of the same class, create a copy of the managed object using the new
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38 | * operator and the managed object's copy constructor, as opposed to
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39 | * std::auto_ptr which simply transfers ownership in these cases.
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40 | *
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41 | * This template is useful for member variables of a class that store
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42 | * dynamically allocated instances of some other class and these instances
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43 | * need to be copied when the containing class instance is copied itself.
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44 | *
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45 | * Be careful when returning instances of this class by value: it will call
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46 | * cause to create a copy of the managed object which is probably is not what
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47 | * you want, especially if its constructor is quite an expensive operation.
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48 | */
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49 | template <typename T>
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50 | class auto_copy_ptr : public std::auto_ptr <T>
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51 | {
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52 | public:
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53 |
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54 | /** @see std::auto_ptr <T>::auto_ptr() */
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55 | auto_copy_ptr (T *p = 0) throw() : std::auto_ptr <T> (p) {}
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56 |
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57 | /**
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58 | * Copy constructor.
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59 | * Takes a copy of the given instance by taking a copy of the managed
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60 | * object using its copy constructor. Both instances will continue to own
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61 | * their objects.
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62 | */
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63 | auto_copy_ptr (const auto_copy_ptr &that) throw()
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64 | : std::auto_ptr <T> (that.get() ? new T (*that.get()) : NULL) {}
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65 |
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66 | /**
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67 | * Assignment operator.
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68 | * Takes a copy of the given instance by taking a copy of the managed
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69 | * object using its copy constructor. Both instances will continue to own
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70 | * their objects.
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71 | */
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72 | auto_copy_ptr &operator= (const auto_copy_ptr &that) throw()
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73 | {
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74 | std::auto_ptr <T>::reset (that.get() ? new T (*that.get()) : NULL);
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75 | return *this;
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76 | }
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77 | };
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78 |
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79 | }; /* namespace cppx */
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80 |
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81 |
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82 | #endif /* __cplusplus */
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83 |
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84 | /** @} */
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85 |
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86 | #endif
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