title: What does it mean for an allocator to be stateless?
body: <p>What does it mean for an allocator to be stateless? I realize that std::allocator is a wrapper around malloc, and has no state of its own. At the same time, malloc does its own bookkeeping, so one could say that all std::allocator instances make use of a single state.</p>
  
  <p>How would I go about implementing a pool allocator without state? If not the allocator, what would keep the current state of memory?</p>
  
  <p>Could someone formally define what state means in this context?</p>