# std::unordered_map::max_size

 size_type max_size() const noexcept; (since C++11)

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.

## Contents

(none)

### Return value

Maximum number of elements.

Constant.

### Notes

This value typically 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_map>

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

Possible output:

Maximum size of a 'unordered_map' is 18446744073709551615