Question

Is there any limit on the size of a std::stack?

I am using a std::stack<std::pair<int,std::string>> as my stack, and when the number of entries exceeds roughly 1 million, I am getting a runtime error.

Is this due to a restriction on the size of std::stack?

Answer 1

std::stack is a container adapter. It is merely a front for some other container, that makes it look like a stack. Consider that std::vector can be treated like a stack if you replace the name push with push_back and the name pop with pop_back. Thus, any size limits or similar are going to be the result of the backing container, not std::stack.

The default backing container for std::stack is std::deque (N3376 23.6.5.2 [stack.defn]). The standard requires that std::deque provide a max_size member function (N3376 23.3.3.1 [deque.overview]/2), which tells you the maximum number of elements that std::deque can hold according to implementation limits. This will typically be something like std::numeric_limits<std::deque<t>::size_type>::max().

However, it is more likely that you are either running into machine memory limits, or have some bug elsewhere in your application causing the runtime error.