Well, you do support only vector containers, by having the limitation of first++ as only iter increment. Your name "array" clashes with the C++ array, which is a compile-time sized vector. And your array is unsafe sized, as last is the only size provision, even unsafer than C++ with its unsafe iterators. With C++ you can it least still bounds check against the vector size.

Your variant being static is indeed nice, the STL, CTL cannot do that, just MTL exists for that. Which supports all containers. E.g. Non-vector types allow for much faster inserts.

You can only replace insitu, which is the opposite of functional. No backtracking. Manual copying needed. The spirit of the STL algorithms is to allocate, not overwrite.

Re hash-map: this is not even finished. For now it's just a pointer-stable unordered_map with optimizations for all types, primitives or strings. optimized Swisstable (string) and Stanford hashes (u64) are in work (no time for that), and are indeed multiple times faster.