Question

As I understand, deque is a cyclic buffer, and when it runs out of space, it allocates new space (if it cans). Is there a way to limit the deque can grow to?
Or the only way to make sure it doesn’t grow over maximum size is to check every time I want to insert data to deque?

Answer 1

Yes, as with every STL collection, one of the templated parameters is an allocator.

So you can write your own custom allocator that will keep a track of the memory and throw bad_alloc if you exceed this limit, even if the memory is available.

Incidentally, a std::deque is usually implemented as a collection of “pages” where each page contains a fixed number of elements.

If you want a circular buffer implementation where you can insert or delete “anywhere”, std::deque would not be the most efficient to use, std::list would be (although there are circular collections available in boost you could use).