std::deque::shrink_to_fit

 

C++

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std::deque

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Capacity

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deque::shrink_to_fit

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void shrink_to_fit();		(since C++11)

Requests the removal of unused capacity.

It is a non-binding request to reduce capacity to size. It depends on the implementation if the request is fulfilled.

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

Parameters

(none)

Return value

(none)

Complexity

Constant

Example

run this code

#include <iostream>
#include <deque>
 
int main()
{
    std::deque<int> v;
    std::cout << "Default-constructed capacity is " << v.capacity() << '\n';
    v.resize(100);
    std::cout << "Capacity of a 100-element deque is " << v.capacity() << '\n';
    v.clear();
    std::cout << "Capacity after clear() is " << v.capacity() << '\n';
    v.shrink_to_fit();
    std::cout << "Capacity after shrink_to_fit() is " << v.capacity() << '\n';
}

Possible output:

Default-constructed capacity is 0
Capacity of a 100-element deque is 100
Capacity after clear() is 100
Capacity after shrink_to_fit() is 0

See also

size	returns the number of elements (public member function)