std::deque::shrink_to_fit

 

C++

Language

Standard library headers

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Utilities library

Strings library

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Algorithms library

Iterators library

Numerics library

Input/output library

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Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Technical Specifications

 

Containers library

array (C++11)

vector

deque

forward_list (C++11)

list

set

multiset

map

multimap

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

stack

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std::deque

Member functions

deque::deque

deque::~deque

deque::operator=

deque::assign

deque::get_allocator

Element access

deque::front

deque::back

Iterators

deque::begindeque::cbegin (C++11)

deque::enddeque::cend (C++11)

deque::rbegindeque::crbegin (C++11)

deque::renddeque::crend (C++11)

Capacity

deque::empty

deque::size

deque::max_size

deque::shrink_to_fit

Modifiers

deque::clear

deque::insert

deque::emplace

deque::erase

deque::push_front

deque::emplace_front

deque::pop_front

deque::push_back

deque::emplace_back

deque::pop_back

deque::resize

deque::swap

 

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)

Type requirements

- T must meet the requirements of MoveInsertable.

Return value

(none)

Complexity

At most linear in the size of the container.

Example

Run this code

#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 will free any unused memory.
    nums.shrink_to_fit();
}

See also

size	returns the number of elements (public member function)