C++11 smart pointers always instead of new/delete?-Collection of common programming errors

unique_ptr doesn’t (isn’t supposed to) have any runtime overhead whatsoever compared to using raw pointers. shared_ptr does have some memory and time overhead (how much depends on the implementation). The practical overhead here can easily be zero if you actually need something that behaves like a shared_ptr (that is, no other implementation you’d think of would be any faster or more memory efficient).

That is not to say you’ll never use new/delete in your code, but it’s not something you’ll do all the time.