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

 

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std::deque

Member types
Member functions
deque::deque deque::~deque deque::operator= deque::assign deque::assign_range (C++23)   deque::get_allocator Element access deque::at deque::operator[] 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 (DR*) Modifiers deque::clear deque::insert deque::insert_range (C++23) deque::emplace deque::erase deque::push_front deque::emplace_front (C++11) deque::prepend_range (C++23) deque::pop_front deque::push_back deque::emplace_back (C++11) deque::append_range (C++23) deque::pop_back deque::resize deque::swap
Non-member functions
operator==operator<=> (C++20) swap(std::deque) erase(std::deque)erase_if(std::deque) (C++20)(C++20)	operator!=operator<operator>operator<=operator>= (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)
Deduction guides(C++17)

 

void assign( size_type count, const T& value );	(1)
template< class InputIt > void assign( InputIt first, InputIt last );	(2)
void assign( std::initializer_list<T> ilist );	(3)	(since C++11)

Replaces the contents of the container.

1) Replaces the contents with count copies of value value.

2) Replaces the contents with copies of those in the range [first, last). The behavior is undefined if either argument is an iterator into *this.

This overload has the same effect as overload (1) if InputIt is an integral type.	(until C++11)
This overload participates in overload resolution only if InputIt satisfies LegacyInputIterator.	(since C++11)

3) Replaces the contents with the elements from the initializer list ilist.

All iterators (including the end() iterator) and all references to the elements are invalidated.

Parameters

count	-	the new size of the container
value	-	the value to initialize elements of the container with
first, last	-	the range to copy the elements from
ilist	-	initializer list to copy the values from

Complexity

1) Linear in count.

2) Linear in distance between first and last.

3) Linear in ilist.size().

Example

The following code uses assign to add several characters to a std::deque<char>:

Run this code

#include <deque>
#include <iostream>
#include <string>
 
int main()
{
    std::deque<char> characters;
 
    auto print_deque = [&]()
    {
        for (char c : characters)
            std::cout << c << ' ';
        std::cout << '\n';
    };
 
    characters.assign(5, 'a');
    print_deque();
 
    const std::string extra(6, 'b');
    characters.assign(extra.begin(), extra.end());
    print_deque();
 
    characters.assign({'C', '+', '+', '1', '1'});
    print_deque();
}

Output:

a a a a a
b b b b b b
C + + 1 1

See also

assign_range (C++23)	assigns a range of values to the container (public member function)
operator=	assigns values to the container (public member function)