Hi Aseem, > Can somebody explain the following behaviour? After you relinquish a pointer to l list, you continue to hold onto the pointer in a. When the A object in l list is deleted, the a pointer is left with a dangling reference. A dangling reference is not guaranteed to cause a segmentation fault when dereferenced. It appears that the heap still had the "ghost" of the A object, which the a pointer accessed -- but it could have also caused a seg fault. The behavior is undefined. There are several strategies you can employ to help you catch programming mistakes like this. One is to use a heap manager that scrubs all released memory to some garbage value. 0xDEADBEEF is a common choice, since it is conspicuous in a debugger. You probably wouldn't want that overhead in production code, but for diagnostic purposes it can be quite handy. Another strategy is to use managed pointers, such as std::auto_ptr or one of the various managed pointed in Boost, which will explicitly relinquish ownership. Another strategy is to use a third party product to help detect this kind of situation. Such as Electric Fence, ValGrind, IBM Rational Purify & Quantify, or Nu-Mega Technologies Bounds Checker... just to name a few. There are a lot out there. q.v. http://www.sdmagazine.com/jolts/prev_utl.htm HTH, --Eljay
