std::vector::shrink_to_fit - cppreference.com

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# std::vector::shrink_to_fit

From cppreference.com
< cpp‎ | container‎ | vector

[edit template]

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, including the past the end iterator, are potentially invalidated.

### [edit] Parameters

(none)

Type requirements
- `T` must meet the requirements of `MoveInsertable`.

### [edit] Return value

(none)

### [edit] 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.

### [edit] Example

[edit]
Run this code

    #include <iostream>
    #include <vector>

    int main()
    {
        std::vector<int> v;
        std::cout << "Default-constructed capacity is " << v.capacity() << '\n';
        v.resize(100);
        std::cout << "Capacity of a 100-element vector 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 vector is 100
    Capacity after clear() is 100
    Capacity after shrink_to_fit() is 0

### [edit] See also

size | returns the number of elements (public member function) [edit]
capacity | returns the number of elements that can be held in currently allocated storage (public member function) [edit]

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