Namespaces
Variants
Views
Actions

std::vector::shrink_to_fit

From cppreference.com
< cpp‎ | container‎ | vector
Revision as of 19:40, 31 May 2013 by P12bot (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
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.

Contents

[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

#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

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