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POC++ delete - It deletes my objects but I can still access the data?
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copied!<p>I have written a simple, working tetris game with each block as an instance of a class singleblock.</p> <pre><code>class SingleBlock { public: SingleBlock(int, int); ~SingleBlock(); int x; int y; SingleBlock *next; }; class MultiBlock { public: MultiBlock(int, int); SingleBlock *c, *d, *e, *f; }; SingleBlock::SingleBlock(int a, int b) { x = a; y = b; } SingleBlock::~SingleBlock() { x = 222; } MultiBlock::MultiBlock(int a, int b) { c = new SingleBlock (a,b); d = c->next = new SingleBlock (a+10,b); e = d->next = new SingleBlock (a+20,b); f = e->next = new SingleBlock (a+30,b); } </code></pre> <p>I have a function that scans for a complete line, and runs through the linked list of blocks deleting the relevant ones and reassigning the ->next pointers.</p> <pre><code>SingleBlock *deleteBlock; SingleBlock *tempBlock; tempBlock = deleteBlock->next; delete deleteBlock; </code></pre> <p>The game works, blocks are deleted correctly and everything functions as it is supposed to. However on inspection I can still access random bits of deleted data.</p> <p>If I printf each of the deleted singleblocks "x" values AFTER their deletion, some of them return random garbage (confirming the deletion) and some of them return 222, telling me even though the destructor was called the data wasn't actually deleted from the heap. Many identical trials show it is always the same specific blocks that are not deleted properly.</p> <p>The results:</p> <pre><code>Existing Blocks: Block: 00E927A8 Block: 00E94290 Block: 00E942B0 Block: 00E942D0 Block: 00E942F0 Block: 00E94500 Block: 00E94520 Block: 00E94540 Block: 00E94560 Block: 00E945B0 Block: 00E945D0 Block: 00E945F0 Block: 00E94610 Block: 00E94660 Block: 00E94680 Block: 00E946A0 Deleting Blocks: Deleting ... 00E942B0, X = 15288000 Deleting ... 00E942D0, X = 15286960 Deleting ... 00E94520, X = 15286992 Deleting ... 00E94540, X = 15270296 Deleting ... 00E94560, X = 222 Deleting ... 00E945D0, X = 15270296 Deleting ... 00E945F0, X = 222 Deleting ... 00E94610, X = 222 Deleting ... 00E94660, X = 15270296 Deleting ... 00E94680, X = 222 </code></pre> <p><strong>Is being able to access data from beyond the grave expected?</strong></p> <p>Sorry if this is a bit long winded.</p>

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