[163] | 1 | /* -*- c++ -*- |
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| 2 | |
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| 3 | C++ smart pointer classes |
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| 4 | |
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| 5 | This file is part of the dpp library of C++ template classes |
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| 6 | |
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| 7 | doc: http://diaxen.ssji.net/dpp/index.html |
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| 8 | repo: https://www.ssji.net/svn/projets/trunk/libdpp |
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| 9 | |
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| 10 | This program is free software: you can redistribute it and/or |
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| 11 | modify it under the terms of the GNU Lesser General Public License |
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| 12 | as published by the Free Software Foundation, either version 3 of |
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| 13 | the License, or (at your option) any later version. |
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| 14 | |
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| 15 | This program is distributed in the hope that it will be useful, but |
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| 16 | WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 18 | Lesser General Public License for more details. |
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| 19 | |
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| 20 | You should have received a copy of the GNU Lesser General Public |
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| 21 | License along with this program. If not, see |
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| 22 | <http://www.gnu.org/licenses/>. |
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| 23 | |
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| 24 | (c) 2008-2011 Alexandre Becoulet <alexandre.becoulet@free.fr> |
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| 25 | |
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| 26 | */ |
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| 27 | |
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| 28 | #ifndef DPP_REFS_HH_ |
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| 29 | #define DPP_REFS_HH_ |
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| 30 | |
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| 31 | #include <cassert> |
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| 32 | #include <cstdlib> |
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| 33 | #include <typeinfo> |
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| 34 | |
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| 35 | /** @file @module{Smart pointer} */ |
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| 36 | |
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| 37 | // #define _DPP_USE_GCC_ATOMIC |
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| 38 | |
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| 39 | namespace dpp { |
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| 40 | |
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| 41 | template <class X> class ref; |
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| 42 | template <class X> class const_ref; |
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| 43 | template <class X> class clone_ref; |
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| 44 | template <class X, bool clonable> class ref_base; |
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| 45 | |
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| 46 | /** @internal |
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| 47 | @module{Smart pointer} |
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| 48 | */ |
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| 49 | template <class X, /* object type with optional constness */ |
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| 50 | class Xnoconst /* bare object type */ > |
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| 51 | class ref_ |
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| 52 | { |
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| 53 | template <class, class> friend class ref_; |
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| 54 | template <class> friend class ref; |
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| 55 | template <class> friend class const_ref; |
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| 56 | template <class> friend class clone_ref; |
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| 57 | |
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| 58 | /** @deprecated |
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| 59 | Dynamically allocate and construct object of given type with passed |
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| 60 | constructor arguments. |
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| 61 | */ |
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| 62 | #define DPP_REFNEW(type, ...) \ |
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| 63 | (dpp::ref<type>::create(__VA_ARGS__)) |
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| 64 | |
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| 65 | public: |
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| 66 | /** @This set the internal pointer to 0. */ |
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| 67 | void invalidate() |
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| 68 | { |
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| 69 | if (_obj) |
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| 70 | _drop(); |
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| 71 | _obj = 0; |
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| 72 | } |
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| 73 | |
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| 74 | /** @This tests if @ref ref points to a valid object. */ |
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| 75 | bool valid() const |
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| 76 | { |
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| 77 | return _obj != 0; |
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| 78 | } |
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| 79 | |
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| 80 | X & operator*() const |
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| 81 | { |
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| 82 | assert(_obj); |
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| 83 | return *_obj; |
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| 84 | } |
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| 85 | |
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| 86 | X * operator->() const |
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| 87 | { |
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| 88 | assert(_obj); |
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| 89 | return _obj; |
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| 90 | } |
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| 91 | |
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| 92 | /** @This returns ref internal object pointer */ |
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| 93 | X * ptr() const |
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| 94 | { |
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| 95 | return _obj; |
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| 96 | } |
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| 97 | |
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| 98 | /** @This returns object references count */ |
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| 99 | int count() const |
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| 100 | { |
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| 101 | return _obj ? _obj->_ref_count : 0; |
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| 102 | } |
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| 103 | |
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| 104 | /** @This tests if pointed objects are the same */ |
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| 105 | bool operator==(const ref_ &r) const |
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| 106 | { |
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| 107 | return _obj == r._obj; |
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| 108 | } |
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| 109 | |
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| 110 | /** @This tests if pointed objects are not the same */ |
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| 111 | bool operator!=(const ref_ &r) const |
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| 112 | { |
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| 113 | return _obj != r._obj; |
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| 114 | } |
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| 115 | |
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| 116 | /** @This tests if pointed objects are the same */ |
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| 117 | bool operator==(const X *p) const |
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| 118 | { |
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| 119 | return _obj == p; |
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| 120 | } |
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| 121 | |
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| 122 | /** @This tests if pointed objects are the same */ |
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| 123 | bool operator!=(const X *p) const |
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| 124 | { |
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| 125 | return _obj != p; |
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| 126 | } |
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| 127 | |
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| 128 | /** @This returns a @ref ref to a new dynamically allocated copy |
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| 129 | of object. Object is deep copyed, new object has the same |
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| 130 | derived type as source object. |
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| 131 | |
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| 132 | While this is not need for objects dynamically allocated with |
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| 133 | the @ref ref::create function, other objects have to call the |
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| 134 | @ref ref_base::set_clone function from their constructor to |
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| 135 | make the @ref clone function work. |
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| 136 | |
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| 137 | The @ref clone_ref class can be used for automatic cloning on |
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| 138 | smart pointer copy. |
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| 139 | |
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| 140 | @example test/test_ref.cc:clone |
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| 141 | */ |
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| 142 | ref<Xnoconst> clone() const |
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| 143 | { |
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| 144 | if (!_obj) |
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| 145 | return ref<Xnoconst>(); |
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| 146 | return ref<Xnoconst>(_obj->template _clone<Xnoconst>()); |
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| 147 | } |
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| 148 | |
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| 149 | private: |
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| 150 | |
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| 151 | /** @internal */ |
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| 152 | void assign(const X &r) |
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| 153 | { |
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| 154 | if (_obj) |
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| 155 | _drop(); |
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| 156 | _obj = &r; |
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| 157 | if (_obj) |
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| 158 | _inc(); |
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| 159 | } |
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| 160 | |
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| 161 | /** @internal */ |
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| 162 | void assign(const ref_ &r) |
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| 163 | { |
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| 164 | if (_obj) |
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| 165 | _drop(); |
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| 166 | _obj = r._obj; |
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| 167 | if (_obj) |
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| 168 | _inc(); |
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| 169 | } |
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| 170 | |
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| 171 | /** @internal */ |
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| 172 | void _inc() const |
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| 173 | { |
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| 174 | _obj->ref_inc(); |
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| 175 | } |
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| 176 | |
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| 177 | /** @internal */ |
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| 178 | void _drop() const |
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| 179 | { |
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| 180 | _obj->ref_drop(); |
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| 181 | } |
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| 182 | |
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| 183 | /** @internal */ |
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| 184 | X *_obj; |
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| 185 | }; |
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| 186 | |
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| 187 | |
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| 188 | /** |
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| 189 | @short Smart pointer class |
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| 190 | @module{Smart pointer} |
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| 191 | @header dpp/ref |
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| 192 | @main |
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| 193 | @order 3 |
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| 194 | |
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| 195 | @This implements an object reference class, it may hold a |
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| 196 | reference to objects of type @tt X which inherit from the @ref |
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| 197 | ref_base class. |
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| 198 | |
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| 199 | This class can hold references to both statically and |
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| 200 | dynamically allocated objects. When the object has been |
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| 201 | dynamically allocated using the @ref create function, it will be |
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| 202 | destroyed when the last reference to the object is dropped. |
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| 203 | |
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| 204 | @see {const_ref, ref_base} |
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| 205 | */ |
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| 206 | template <class X> |
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| 207 | class ref : public ref_<X, X> |
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| 208 | { |
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| 209 | template <class, class> friend class ref_; |
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| 210 | template <class> friend class ref; |
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| 211 | template <class> friend class clone_ref; |
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| 212 | typedef ref_<X, X> base; |
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| 213 | |
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| 214 | explicit ref(X * obj) |
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| 215 | { |
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| 216 | base::_obj = obj; |
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| 217 | } |
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| 218 | |
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| 219 | public: |
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| 220 | |
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| 221 | /** @multiple |
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| 222 | @This dynamically allocates and construct object. Parameters |
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| 223 | are passed to constructor. */ |
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| 224 | static ref create() |
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| 225 | { |
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| 226 | X *obj = new X(); |
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| 227 | obj->template _set_clone<X>(); |
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| 228 | obj->_dynamic = true; |
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| 229 | obj->_ref_count = 1; |
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| 230 | return ref(obj); |
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| 231 | } |
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| 232 | |
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| 233 | template <typename A0> |
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| 234 | static ref create(const A0 &a0) |
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| 235 | { |
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| 236 | X *obj = new X(a0); |
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| 237 | obj->template _set_clone<X>(); |
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| 238 | obj->_dynamic = true; |
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| 239 | obj->_ref_count = 1; |
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| 240 | return ref(obj); |
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| 241 | } |
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| 242 | |
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| 243 | template <typename A0, typename A1> |
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| 244 | static ref create(const A0 &a0, const A1 &a1) |
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| 245 | { |
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| 246 | X *obj = new X(a0, a1); |
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| 247 | obj->template _set_clone<X>(); |
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| 248 | obj->_dynamic = true; |
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| 249 | obj->_ref_count = 1; |
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| 250 | return ref(obj); |
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| 251 | } |
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| 252 | |
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| 253 | template <typename A0, typename A1, typename A2> |
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| 254 | static ref create(const A0 &a0, const A1 &a1, const A2 &a2) |
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| 255 | { |
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| 256 | X *obj = new X(a0, a1, a2); |
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| 257 | obj->template _set_clone<X>(); |
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| 258 | obj->_dynamic = true; |
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| 259 | obj->_ref_count = 1; |
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| 260 | return ref(obj); |
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| 261 | } |
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| 262 | |
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| 263 | template <typename A0, typename A1, typename A2, |
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| 264 | typename A3> |
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| 265 | static ref create(const A0 &a0, const A1 &a1, const A2 &a2, |
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| 266 | const A3 &a3) |
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| 267 | { |
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| 268 | X *obj = new X(a0, a1, a2, a3); |
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| 269 | obj->template _set_clone<X>(); |
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| 270 | obj->_dynamic = true; |
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| 271 | obj->_ref_count = 1; |
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| 272 | return ref(obj); |
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| 273 | } |
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| 274 | |
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| 275 | template <typename A0, typename A1, typename A2, |
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| 276 | typename A3, typename A4> |
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| 277 | static ref create(const A0 &a0, const A1 &a1, const A2 &a2, |
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| 278 | const A3 &a3, const A4 &a4) |
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| 279 | { |
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| 280 | X *obj = new X(a0, a1, a2, a3, a4); |
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| 281 | obj->template _set_clone<X>(); |
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| 282 | obj->_dynamic = true; |
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| 283 | obj->_ref_count = 1; |
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| 284 | return ref(obj); |
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| 285 | } |
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| 286 | |
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| 287 | template <typename A0, typename A1, typename A2, |
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| 288 | typename A3, typename A4, typename A5> |
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| 289 | static ref create(const A0 &a0, const A1 &a1, const A2 &a2, |
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| 290 | const A3 &a3, const A4 &a4, const A5 &a5) |
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| 291 | { |
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| 292 | X *obj = new X(a0, a1, a2, a3, a4, a5); |
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| 293 | obj->template _set_clone<X>(); |
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| 294 | obj->_dynamic = true; |
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| 295 | obj->_ref_count = 1; |
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| 296 | return ref(obj); |
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| 297 | } |
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| 298 | |
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| 299 | /** @This performs a dynamic cast to @ref ref of given type */ |
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| 300 | template <class T> |
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| 301 | ref<T> dynamiccast() const |
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| 302 | { |
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| 303 | T *r = dynamic_cast<T*>(base::_obj); |
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| 304 | if (r) |
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| 305 | base::_inc(); |
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| 306 | return ref<T>(r); |
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| 307 | } |
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| 308 | |
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| 309 | /** @This performs a static cast to @ref ref of given type */ |
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| 310 | template <class T> |
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| 311 | ref<T> staticcast() const |
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| 312 | { |
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| 313 | if (base::_obj) |
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| 314 | base::_inc(); |
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| 315 | return ref<T>(static_cast<T*>(base::_obj)); |
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| 316 | } |
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| 317 | |
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| 318 | /** Construct an empty ref */ |
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| 319 | ref() |
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| 320 | { |
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| 321 | base::_obj = 0; |
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| 322 | } |
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| 323 | |
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| 324 | /** Construct ref from ref */ |
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| 325 | ref(const ref &r) |
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| 326 | { |
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| 327 | if ((base::_obj = r._obj)) |
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| 328 | base::_inc(); |
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| 329 | } |
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| 330 | |
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| 331 | /** Construct ref from derived class ref */ |
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| 332 | template <class T> |
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| 333 | ref(const ref_<T, T> &r) |
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| 334 | { |
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| 335 | if ((base::_obj = r._obj)) |
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| 336 | base::_inc(); |
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| 337 | } |
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| 338 | |
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| 339 | /** Construct ref from object reference */ |
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| 340 | ref(X &obj) |
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| 341 | { |
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| 342 | base::_obj = &obj; |
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| 343 | base::_inc(); |
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| 344 | } |
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| 345 | |
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| 346 | /** Drop a ref */ |
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| 347 | ~ref() |
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| 348 | { |
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| 349 | if (base::_obj) |
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| 350 | base::_drop(); |
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| 351 | } |
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| 352 | |
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| 353 | /** Initialize ref from ref */ |
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| 354 | ref & operator=(const ref &r) |
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| 355 | { |
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| 356 | base::assign(r); |
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| 357 | return *this; |
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| 358 | } |
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| 359 | |
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| 360 | /** Initialize ref from object reference */ |
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| 361 | ref & operator=(X & obj) |
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| 362 | { |
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| 363 | base::assign(obj); |
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| 364 | return *this; |
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| 365 | } |
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| 366 | |
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| 367 | }; |
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| 368 | |
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| 369 | /** |
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| 370 | @short Const smart pointer class |
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| 371 | @module{Smart pointer} |
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| 372 | @header dpp/ref |
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| 373 | @main |
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| 374 | @order 2 |
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| 375 | |
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| 376 | @This class is the same as the @ref ref class but hold a @b |
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| 377 | const pointer to the object. |
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| 378 | |
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| 379 | @see {ref, ref_base} |
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| 380 | */ |
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| 381 | template <class X> |
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| 382 | class const_ref : public ref_<const X, X> |
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| 383 | { |
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| 384 | template <class, class> friend class ref_; |
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| 385 | typedef ref_<const X, X> base; |
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| 386 | |
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| 387 | explicit const_ref(const X * obj) |
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| 388 | { |
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| 389 | base::_obj = obj; |
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| 390 | } |
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| 391 | |
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| 392 | public: |
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| 393 | |
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| 394 | /** Construct an empty ref */ |
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| 395 | const_ref() |
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| 396 | { |
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| 397 | base::_obj = 0; |
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| 398 | } |
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| 399 | |
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| 400 | /** Construct const ref from const ref */ |
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| 401 | const_ref(const const_ref &r) |
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| 402 | { |
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| 403 | if ((base::_obj = r._obj)) |
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| 404 | base::_inc(); |
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| 405 | } |
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| 406 | |
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| 407 | /** Construct const ref from derived class ref */ |
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| 408 | template <class T> |
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| 409 | const_ref(const ref_<T, T> &r) |
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| 410 | { |
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| 411 | if ((base::_obj = r._obj)) |
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| 412 | base::_inc(); |
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| 413 | } |
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| 414 | |
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| 415 | /** Construct const ref from derived class const ref */ |
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| 416 | template <class T> |
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| 417 | const_ref(const ref_<const T, T> &r) |
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| 418 | { |
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| 419 | if ((base::_obj = r._obj)) |
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| 420 | base::_inc(); |
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| 421 | } |
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| 422 | |
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| 423 | /** Construct ref from const object reference */ |
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| 424 | const_ref(const X &obj) |
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| 425 | { |
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| 426 | base::_obj = &obj; |
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| 427 | base::_inc(); |
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| 428 | } |
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| 429 | |
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| 430 | /** Drop a ref */ |
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| 431 | ~const_ref() |
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| 432 | { |
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| 433 | if (base::_obj) |
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| 434 | base::_drop(); |
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| 435 | } |
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| 436 | |
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| 437 | /** @This performs a dynamic cast to @ref const_ref of given type */ |
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| 438 | template <class T> |
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| 439 | const_ref<T> dynamiccast() const |
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| 440 | { |
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| 441 | const T *r = dynamic_cast<const T*>(base::_obj); |
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| 442 | if (r) |
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| 443 | base::_inc(); |
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| 444 | return const_ref<T>(r); |
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| 445 | } |
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| 446 | |
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| 447 | /** @This performs a static cast to @ref const_ref of given type */ |
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| 448 | template <class T> |
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| 449 | const_ref<T> staticcast() const |
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| 450 | { |
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| 451 | if (base::_obj) |
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| 452 | base::_inc(); |
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| 453 | return const_ref<T>(static_cast<const T*>(base::_obj)); |
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| 454 | } |
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| 455 | |
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| 456 | /** Initialize const ref from const ref */ |
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| 457 | const_ref & operator=(const const_ref &r) |
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| 458 | { |
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| 459 | base::assign(r); |
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| 460 | return *this; |
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| 461 | } |
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| 462 | |
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| 463 | /** Initialize ref from object reference */ |
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| 464 | const_ref & operator=(const X & obj) |
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| 465 | { |
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| 466 | base::assign(obj); |
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| 467 | return *this; |
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| 468 | } |
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| 469 | |
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| 470 | }; |
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| 471 | |
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| 472 | /** |
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| 473 | @short Automatic cloning smart pointer class |
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| 474 | @module{Smart pointer} |
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| 475 | @header dpp/ref |
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| 476 | @main |
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| 477 | @order 1 |
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| 478 | |
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| 479 | @This implements a special kind of smart pointer which clones the |
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| 480 | pointed object when copied. It is intended to be used for class |
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| 481 | members when the expected behavior is to clone the pointed |
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| 482 | object along with the reference holder object. |
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| 483 | |
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| 484 | The copy constructor and copy assignment operator will clone the |
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| 485 | associated object instead of just copying the |
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| 486 | pointer. Constructors and assignment operators which take other |
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| 487 | kind of references don't perform clone. |
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| 488 | |
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| 489 | @example test/test_ref.cc:clone1 |
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| 490 | |
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| 491 | @see {ref, ref_base} |
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| 492 | */ |
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| 493 | template <class X> |
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| 494 | class clone_ref : public ref_<X, X> |
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| 495 | { |
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| 496 | template <class, class> friend class ref_; |
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| 497 | typedef ref_<X, X> base; |
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| 498 | |
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| 499 | public: |
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| 500 | |
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| 501 | /** Construct an empty ref */ |
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| 502 | clone_ref() |
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| 503 | { |
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| 504 | base::_obj = 0; |
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| 505 | } |
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| 506 | |
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| 507 | /** Construct ref from derived class ref */ |
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| 508 | template <class T> |
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| 509 | clone_ref(const ref_<T, T> &r) |
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| 510 | { |
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| 511 | base::_obj = r._obj; |
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| 512 | if (base::_obj) |
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| 513 | base::_inc(); |
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| 514 | } |
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| 515 | |
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| 516 | /** Construct clone_ref and clone pointed object */ |
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| 517 | clone_ref(const clone_ref &r) |
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| 518 | { |
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| 519 | base::_obj = r._obj ? r._obj->template _clone<X>() : 0; |
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| 520 | } |
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| 521 | |
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| 522 | /** Construct clone_ref and clone pointed object */ |
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| 523 | template <class T> |
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| 524 | clone_ref(const clone_ref &r) |
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| 525 | { |
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| 526 | base::_obj = r._obj ? r._obj->template _clone<X>() : 0; |
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| 527 | } |
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| 528 | |
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| 529 | /** Construct clone_ref from object reference */ |
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| 530 | clone_ref(X &obj) |
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| 531 | { |
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| 532 | base::_obj = &obj; |
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| 533 | base::_inc(); |
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| 534 | } |
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| 535 | |
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| 536 | /** Drop a clone_ref */ |
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| 537 | ~clone_ref() |
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| 538 | { |
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| 539 | if (base::_obj) |
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| 540 | base::_drop(); |
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| 541 | } |
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| 542 | |
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| 543 | /** @This performs a dynamic cast to @ref ref of given type */ |
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| 544 | template <class T> |
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| 545 | ref<T> dynamiccast() const |
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| 546 | { |
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| 547 | T *r = dynamic_cast<T*>(base::_obj); |
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| 548 | if (r) |
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| 549 | base::_inc(); |
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| 550 | return ref<T>(r); |
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| 551 | } |
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| 552 | |
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| 553 | /** @This performs a static cast to @ref ref of given type */ |
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| 554 | template <class T> |
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| 555 | ref<T> staticcast() const |
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| 556 | { |
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| 557 | if (base::_obj) |
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| 558 | base::_inc(); |
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| 559 | return ref<T>(static_cast<T*>(base::_obj)); |
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| 560 | } |
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| 561 | |
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| 562 | /** Initialize clone_ref by cloning object */ |
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| 563 | clone_ref & operator=(const clone_ref &r) |
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| 564 | { |
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| 565 | if (base::_obj) |
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| 566 | base::_drop(); |
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| 567 | base::_obj = r._obj ? r._obj->_clone() : 0; |
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| 568 | return *this; |
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| 569 | } |
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| 570 | |
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| 571 | /** Initialize ref from ref */ |
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| 572 | clone_ref & operator=(const ref<X> &r) |
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| 573 | { |
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| 574 | base::assign(r); |
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| 575 | return *this; |
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| 576 | } |
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| 577 | |
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| 578 | /** Initialize ref from object reference */ |
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| 579 | clone_ref & operator=(X & obj) |
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| 580 | { |
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| 581 | base::assign(obj); |
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| 582 | return *this; |
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| 583 | } |
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| 584 | |
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| 585 | }; |
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| 586 | |
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| 587 | /** @internal |
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| 588 | @module{Smart pointer} |
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| 589 | */ |
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| 590 | template <class X, bool cloneable> |
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| 591 | class ref_base_ |
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| 592 | { |
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| 593 | template <class> friend class ref; |
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| 594 | |
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| 595 | template <class D> |
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| 596 | void _set_clone() |
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| 597 | { |
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| 598 | /* not cloneable, no clone callback registered here */ |
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| 599 | } |
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| 600 | }; |
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| 601 | |
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| 602 | /** @internal |
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| 603 | @module{Smart pointer} |
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| 604 | This class contains cloning code. |
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| 605 | */ |
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| 606 | template <class X> |
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| 607 | class ref_base_ <X, true> |
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| 608 | { |
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| 609 | template <class, class> friend class ref_; |
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| 610 | template <class> friend class ref; |
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| 611 | template <class> friend class clone_ref; |
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| 612 | template <class, bool> friend class ref_base; |
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| 613 | |
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| 614 | ref_base_() |
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| 615 | : _ref_clone(0) |
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| 616 | { |
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| 617 | } |
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| 618 | |
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| 619 | /** Clone object pointed by ref */ |
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| 620 | template <class D> |
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| 621 | D * _clone() const |
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| 622 | { |
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| 623 | assert(_ref_clone || !"no clone handler defined for this object"); |
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| 624 | return static_cast<D*>(_ref_clone(static_cast<const D*>(this))); |
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| 625 | } |
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| 626 | |
---|
| 627 | template <class D /* derived class */> |
---|
| 628 | static X * _clone_hndl(const X *x) |
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| 629 | { |
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| 630 | assert(typeid(D) == typeid(*x) && "clone handler does not match actual object type"); |
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| 631 | const D * src = static_cast<const D*>(x); |
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| 632 | D * obj = new D(*src); |
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| 633 | obj->_ref_clone = src->_ref_clone; |
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| 634 | obj->_dynamic = true; |
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| 635 | obj->_ref_count = 1; |
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| 636 | obj->cloned(*src); |
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| 637 | return obj; |
---|
| 638 | } |
---|
| 639 | |
---|
| 640 | /** set specialized clone callback */ |
---|
| 641 | template <class D> |
---|
| 642 | void _set_clone() |
---|
| 643 | { |
---|
| 644 | _ref_clone = &_clone_hndl<D>; |
---|
| 645 | } |
---|
| 646 | |
---|
| 647 | /** pointer to clone function specialized for _derived_ class */ |
---|
| 648 | X * (*_ref_clone)(const X *); |
---|
| 649 | }; |
---|
| 650 | |
---|
| 651 | /** |
---|
| 652 | @short Reference counting object base class |
---|
| 653 | @module{Smart pointer} |
---|
| 654 | @header dpp/ref |
---|
| 655 | @showvalue |
---|
| 656 | |
---|
| 657 | @This is the referenced object base class, any class which |
---|
| 658 | inherits from this class can be pointed to by a @ref ref smart |
---|
| 659 | pointer. |
---|
| 660 | |
---|
| 661 | @tt X template parameter must be the same as inheriting class. |
---|
| 662 | |
---|
| 663 | The @tt cloneable parameter must be set to true in order to use |
---|
| 664 | the @ref ref::clone method. The default value is @tt false to |
---|
| 665 | support classes with no copy constructor and optimize pointer size. |
---|
| 666 | |
---|
| 667 | When the DPP_REF_LIVE_REFS_ASSERT macro is defined, the base |
---|
| 668 | class destructor assert that no more live reference to the |
---|
| 669 | object does exist. |
---|
| 670 | */ |
---|
| 671 | template <class X, bool cloneable = false> |
---|
| 672 | class ref_base : public ref_base_<X, cloneable> |
---|
| 673 | { |
---|
| 674 | template <class, class> friend class ref_; |
---|
| 675 | template <class> friend class ref; |
---|
| 676 | template <class> friend class const_ref; |
---|
| 677 | template <class, bool> friend class ref_base_; |
---|
| 678 | |
---|
| 679 | public: |
---|
| 680 | |
---|
| 681 | ref_base() |
---|
| 682 | : _ref_count(0), |
---|
| 683 | _dynamic(0) |
---|
| 684 | { |
---|
| 685 | } |
---|
| 686 | |
---|
| 687 | ref_base(const ref_base &r) |
---|
| 688 | : _ref_count(0), |
---|
| 689 | _dynamic(0) |
---|
| 690 | { |
---|
| 691 | } |
---|
| 692 | |
---|
| 693 | ref_base & operator=(const ref_base &r) |
---|
| 694 | { |
---|
| 695 | return *this; |
---|
| 696 | } |
---|
| 697 | |
---|
| 698 | virtual ~ref_base() |
---|
| 699 | { |
---|
| 700 | #ifdef DPP_REF_LIVE_REFS_ASSERT |
---|
| 701 | assert(_ref_count == 0 || !"Can not destruct object which has live references"); |
---|
| 702 | #endif |
---|
| 703 | } |
---|
| 704 | |
---|
| 705 | /** Setup a clone handler for this object. This function may be |
---|
| 706 | called from derived class constructor to make objects |
---|
| 707 | cloneable. Objects which are dynamically allocated using the |
---|
| 708 | @ref ref::create function do not require this call. */ |
---|
| 709 | template <class Derived> |
---|
| 710 | void set_clone() |
---|
| 711 | { |
---|
| 712 | ref_base_<X, cloneable>::template _set_clone<Derived>(); |
---|
| 713 | } |
---|
| 714 | |
---|
| 715 | /** @This is called when this object has just been cloned. The |
---|
| 716 | call is performed on most derived class (see @ref set_clone |
---|
| 717 | function). This default implementation is empty. */ |
---|
| 718 | void cloned(const X &src) |
---|
| 719 | { |
---|
| 720 | } |
---|
| 721 | |
---|
| 722 | /** @This is called when the reference counter has just been |
---|
| 723 | increased. The call is performed on reference to @tt X class so |
---|
| 724 | a virtual prototype must be declared in the @tt X class to |
---|
| 725 | override this function from further derived classes. |
---|
| 726 | This default implementation is empty. |
---|
| 727 | @see ref_decreased @see ref_inc |
---|
| 728 | */ |
---|
| 729 | void ref_increased(int ref_count) const |
---|
| 730 | { |
---|
| 731 | } |
---|
| 732 | |
---|
| 733 | /** Same as @ref ref_increased but called when the counter has |
---|
| 734 | been decreased. This default implementation is empty. |
---|
| 735 | @see ref_dec |
---|
| 736 | */ |
---|
| 737 | void ref_decreased(int ref_count) const |
---|
| 738 | { |
---|
| 739 | } |
---|
| 740 | |
---|
| 741 | /** @This increases references count on object. It should only be |
---|
| 742 | used on rare cases when smart pointer classes can not be used |
---|
| 743 | to track all references to the object. @see ref_drop */ |
---|
| 744 | void ref_inc() const |
---|
| 745 | { |
---|
| 746 | #ifdef _DPP_USE_GCC_ATOMIC |
---|
| 747 | # if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ |
---|
| 748 | __sync_add_and_fetch(&const_cast<ref_base*>(this)->_raw, 1); |
---|
| 749 | # elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ |
---|
| 750 | __sync_add_and_fetch(&const_cast<ref_base*>(this)->_raw, 2); |
---|
| 751 | # else |
---|
| 752 | # error __BYTE_ORDER__ not defined |
---|
| 753 | # endif |
---|
| 754 | #else |
---|
| 755 | const_cast<ref_base*>(this)->_ref_count++; |
---|
| 756 | #endif |
---|
| 757 | |
---|
| 758 | static_cast<const X*>(this)->ref_increased(_ref_count); |
---|
| 759 | } |
---|
| 760 | |
---|
| 761 | /** @This decreases references count on object. Dynamically |
---|
| 762 | allocated objects are deleted if counter reaches 0. It should |
---|
| 763 | only be used on rare cases when smart pointer classes can not |
---|
| 764 | be used to track all references to the object. @see ref_inc */ |
---|
| 765 | void ref_drop() const |
---|
| 766 | { |
---|
| 767 | assert(_ref_count > 0); |
---|
| 768 | |
---|
| 769 | #ifdef _DPP_USE_GCC_ATOMIC |
---|
| 770 | # if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ |
---|
| 771 | __sync_sub_and_fetch(&const_cast<ref_base*>(this)->_raw, 1); |
---|
| 772 | # elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ |
---|
| 773 | __sync_sub_and_fetch(&const_cast<ref_base*>(this)->_raw, 2); |
---|
| 774 | # endif |
---|
| 775 | #else |
---|
| 776 | const_cast<ref_base*>(this)->_ref_count--; |
---|
| 777 | #endif |
---|
| 778 | |
---|
| 779 | static_cast<const X*>(this)->ref_decreased(_ref_count); |
---|
| 780 | |
---|
| 781 | // free dynamically allocated objects only |
---|
| 782 | if (_dynamic && _ref_count == 0) |
---|
| 783 | delete this; |
---|
| 784 | } |
---|
| 785 | |
---|
| 786 | private: |
---|
| 787 | |
---|
| 788 | /** reference counter value */ |
---|
| 789 | union { |
---|
| 790 | struct { |
---|
| 791 | int _ref_count:31; |
---|
| 792 | int _dynamic:1; |
---|
| 793 | }; |
---|
| 794 | int _raw; |
---|
| 795 | }; |
---|
| 796 | }; |
---|
| 797 | |
---|
| 798 | } |
---|
| 799 | |
---|
| 800 | #endif |
---|
| 801 | |
---|