std::deque<T,Allocator>::shrink_to_fit

void shrink_to_fit();

Requests the removal of unused capacity.

It is a non-binding request to reduce the memory usage without changing the size of the sequence. It depends on the implementation whether the request is fulfilled.

All iterators and references are invalidated. Past-the-end iterator is also invalidated.

Parameters

(none).

Return value

(none).

Complexity

At most linear in the size of the container.

Notes

If an exception is thrown other than by T's move constructor, there are no effects.

Example

#include <deque>
 
int main() {
    std::deque<int> nums(1000, 42);
    nums.push_front(1);
    nums.pop_front();
 
    nums.clear();
 
    // nums now contains no items, but it may still be holding allocated memory. 
    // Calling shrink_to_fit may free any unused memory.
    nums.shrink_to_fit();
}

See also