Regarding compiler deleting memset, there are multiple memory-zeroing functions that are guaranteed not to be optimized away: https://cppreference.com/c/string

Regarding compiler deleting memset, there are multiple memory-zeroing functions that are guaranteed not to be optimized away: https://cppreference.com/c/string/byte/memset https://cppreference.com/c/string/byte/memset (memset_s) https://cppreference.com/cpp/string/byte/memset https://cppreference.com/cpp/string/byte/memset (memset_explicit) Also see notes section for various other functions that people were using before memset_s became standard.