language agnostic - Which data structure is this?

Question

What is the name of the data structure, if one exists, that has the operations below?

• You can insert an element and you are given a key.
• You can retrieve an element by its key.

question from:https://stackoverflow.com/questions/5921636/which-data-structure-is-this

Answer 1

Memory Allocator

You allocate (insert) an element, and given a key (pointer, reference, etc.) you can retrieve the element (access it) by the pointer reference.