Regarding uninitialized variables, there is a proposal to make them default to zero-initialized: http://wg21.link/P2723 http://wg21.link/P2723 Under "5. Perfo

Regarding uninitialized variables, there is a proposal to make them default to zero-initialized: http://wg21.link/P2723 http://wg21.link/P2723 Under "5. Performance" section, it claims the performance impact to be negligible, and there is also a mechanism to opt-out.