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

void resize( size_type count );

void resize( size_type count, const value_type& value );

Resizes the container to contain count elements, does nothing if count == size().

If the current size is greater than count, the container is reduced to its first count elements.

If the current size is less than count,

Parameters

Return value

(none).

Complexity

Linear in the difference between the current size and count.

Notes

If value-initialization in overload (1) is undesirable, for example, if the elements are of non-class type and zeroing out is not needed, it can be avoided by providing a custom Allocator::construct.

Example

#include <iostream>
#include <deque>
 
int main()
{
    std::deque<int> c = {1, 2, 3};
    std::cout << "The deque holds: ";
    for (const auto& el: c)
        std::cout << el << ' ';
    std::cout << '\n';
 
    c.resize(5);
    std::cout << "After resize up to 5: ";
    for (const auto& el: c)
        std::cout << el << ' ';
    std::cout << '\n';
 
    c.resize(2);
    std::cout << "After resize down to 2: ";
    for (const auto& el: c)
        std::cout << el << ' ';
    std::cout << '\n';
 
    c.resize(6, 4);
    std::cout << "After resize up to 6 (initializer = 4): ";
    for (const auto& el: c)
        std::cout << el << ' ';
    std::cout << '\n';
}

The deque holds: 1 2 3
After resize up to 5: 1 2 3 0 0
After resize down to 2: 1 2
After resize up to 6 (initializer = 4): 1 2 4 4 4 4

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

See also