Memory Leak and user 42

User 42 commonly occours if you are:

1. Trying to delete an object that is already deleted. (If two classes share a pointer, make sure only one of them is the "owner" responsible for deleting it)

2. writeing outside the bounds of an array or similar, corrupting a pointer allocated next to it, that you then try to free. (For example an array as a member variable)

3. writeing outside the bounds of an array or similar, that is allocated on the heap, corrupting the heap cell after the array, causing user 42 when trying to delete that cell...

Alh summarizes three common causes from the "Memory Leak and user 42" post on newlc.
Address: http://www.newlc.com/topic-8935