std::unordered_set::max_size

size_type max_size() const;

Returns the maximum number of elements the container is able to hold due to system or library implementation limitations, i.e. std::distance(begin(), end()) for the largest container.

Parameters

(none).

Return value

Maximum number of elements.

Exceptions

Complexity

Constant.

Notes

This value is typically equal to std::numeric_limits<size_type>::max(), and reflects the theoretical limit on the size of the container. At runtime, the size of the container may be limited to a value smaller than max_size() by the amount of RAM available.

Example

#include <iostream>
#include <unordered_set>
 
int main()
{
    std::unordered_set<char> s;
    std::cout << "Maximum size of a 'unordered_set' is " << s.max_size() << "\n";
}

Maximum size of a 'unordered_set' is 18446744073709551615

See also