>One thing Rust's vector guarantees that C++ doesn't is that Rust's vector will not store elements inline; anything (with nonzero size) you push into it will be

>One thing Rust's vector guarantees that C++ doesn't is that Rust's vector will not store elements inline; anything (with nonzero size) you push into it will be heap allocated. I believe this is incorrect and small-vector optimization is in fact disallowed by the C++ standard. In any case, standard or not, no implementation is ever going to do SVO because it would require a branch on every access, making them incompatible with SIMD instructions. >Rust also has a concept of zero sized types, which C++ does not No, C++ allows this optimization too, it just requires that the "sizeof" operator always returns an integer >= 1.