Hi Guys. I need serious help here, though this is child's play for you all.

From boost/checked_delete.hpp (attached),

template<class T> inline void checked_delete(T * x) { // intentionally complex - simplification causes regressions typedef char type_must_be_complete[ sizeof(T)? 1: -1 ]; (void) sizeof(type_must_be_complete); delete x; } template<class T> inline void checked_array_delete(T * x) { typedef char type_must_be_complete[ sizeof(T)? 1: -1 ]; (void) sizeof(type_must_be_complete); delete [] x; } * What's the result of applying sizeof to an incomplete type? * Why is sizeof called twice? * Why is the result of sizeof cast to void? What exactly does that line do? * Is it an empty statement if the sizeof is legal? * Why not apply x = 0; at the end? This code is not too clear to me & the boost documentation is not either. Please assist. Please do not direct me to the C++ standard text. Then again, smart pointers are simple to understand & use, but their implementations are all rather difficult to understand (maybe except scoped_ptr). Which brings me to one more question, why wasn't Andrei's technique of Smart_Ptr (Loki) chosen over the boost implementation technique (a class per smart pointer) for C++ 0x? His allows for an innumerable number of extension through policies. I ask this purely to understand why, not as a rejoinder. Awaiting your feedback. Thank you. Nice day. ______________________________________________________________________ Kizza George Mbidde Interconnect Billing Systems Analyst IT cell: +256 77 221 2982 email: mbiddeg@mtn.co.ug [cid:image001.gif@01C9E853.125FFD20]