std::unordered_map is a Joke

http://www.reedbeta.com/blog/data-oriented-hash-table/

>>6
3Arrays:
New array(realloc if < current_size),Old Array(switches to New Array, as if it was a Framebuffer backpage, with realloc if <current_size)
Stack edit array: elements are {edit operation,element number,new value}; when it fills, all edits are performed in New Array(resized by keeping current_size consistent with edit ops(by +/- for each new stack item)),Old Array is repurposed as next New Array.