Hi, I waited until the thread went beyond the first page to further engage with you. I can tell you why your employer has this requirement. This is common on mission-critical software. Exceptions and Stack Unwinding in C++[^] If you allocate memory on the stack... and a recoverable exception occurs in your thread... the memory is correctly released during stack unwinding. If you allocate memory on the heap and a recoverable exception occurs in your thread... the memory is not released and now your application potentially has a resource leak. leon de boer wrote: As they said you can't hack it and is guaranteed to perform error-free, that isn't a claim it's a provable fact. This is not correct. I have met both Bryan Parno[^] and Jeannette Wing[^] and I was present at the 2014 presentation on campus at Redmond. Yes, small sections of logic can be statistically proven to be secure. It would not be correct to make the claim of "guaranteed to perform error-free, that isn't a claim it's a provable fact" If I were to assign a confidence level to what they have achieved I would say "High Confidence". Best Wishes, -David Delaune

_tcscpy_s and it's variants only guarantee that the string will be copied IF it fits. I suspect that the compiler "figured out" that it could safely optimize the copy using 32 or 64 bit chunks. This would result in satisfying the condition that the string be null terminated, but would also end up copying random data stored after the original string.