play around with use_count()
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1 changed files with 7 additions and 0 deletions
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@ -6,14 +6,19 @@
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void shared_ptr() {
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std::shared_ptr<int> p1(new int(5));
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std::shared_ptr<int> p2 = p1; // Both now own the memory.
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assert(p1.use_count() == 2);
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// Memory still exists, due to p2:
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p1.reset();
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assert(p1.get() == NULL && p2.get() != NULL);
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assert(p2.use_count() == 1);
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assert(p1.use_count() == 0);
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// Deletes the memory, since no one else owns the memory.
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p2.reset();
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assert(p1.get() == NULL && p2.get() == NULL);
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assert(p2.use_count() == 0);
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assert(p1.use_count() == 0);
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}
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void weak_ptr() {
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@ -30,8 +35,10 @@ void weak_ptr() {
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} // p2 is destroyed. Memory is owned by p1.
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assert(wp1.lock() != NULL);
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assert(wp1.use_count() == 1);
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p1.reset(); // Memory is deleted.
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assert(wp1.lock() == NULL);
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assert(wp1.use_count() == 0);
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std::shared_ptr<int> p3 = wp1.lock();
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// Memory is gone, so we get an empty shared_ptr.
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