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1 #pragma once
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2
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3 // PFC weakRef class
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4 // Create weak references to objects that automatically become invalidated upon destruction of the object
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5 // Note that this is NOT thread safe and meant for single thread usage. If you require thread safety, provide your own means, such as mutexlocking of weakRef::get() and the destruction of your objects.
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6
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7 #include <memory> // std::shared_ptr
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8
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9 namespace pfc {
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10 typedef std::shared_ptr<const bool> weakRefKillSwitch_t;
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11
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12 template<typename target_t>
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13 class weakRef {
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14 typedef weakRef<target_t> self_t;
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15 public:
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16 static self_t _make(target_t * target, weakRefKillSwitch_t ks) {
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17 self_t ret;
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18 ret.m_target = target;
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19 ret.m_ks = ks;
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20 return ret;
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21 }
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22
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23
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24 bool isValid() const {
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25 return m_ks && !*m_ks;
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26 }
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27
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28 target_t * get() const {
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29 if (!isValid()) return nullptr;
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30 return m_target;
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31 }
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32 target_t * operator() () const {
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33 return get();
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34 }
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35 private:
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36 target_t * m_target = nullptr;
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37 weakRefKillSwitch_t m_ks;
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38 };
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39
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40 template<typename class_t>
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41 class weakRefTarget {
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42 public:
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43 weakRefTarget() {}
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44
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45 typedef weakRef<class_t> weakRef_t;
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46
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47 weakRef<class_t> weakRef() {
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48 PFC_ASSERT(!*m_ks);
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49 class_t * ptr = static_cast<class_t*>(this);
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50 return weakRef_t::_make(ptr, m_ks);
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51 }
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52
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53 // Optional: explicitly invalidates all weak references to this object. Called implicitly by the destructor, but you can do it yourself earlier.
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54 void weakRefShutdown() {
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55 *m_ks = true;
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56 }
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57 ~weakRefTarget() {
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58 weakRefShutdown();
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59 }
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60
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61 // Optional: obtain a reference to the killswitch if you wish to use it directly
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62 weakRefKillSwitch_t weakRefKS() const {
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63 return m_ks;
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64 }
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65 private:
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66 std::shared_ptr<bool> m_ks = std::make_shared<bool>(false);
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67
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68 weakRefTarget(const weakRefTarget &) = delete;
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69 void operator=(const weakRefTarget &) = delete;
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70 };
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71 }
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