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

 

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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 push_front(const T& value );	(1)	(constexpr since C++26)
void push_front( T&& value );	(2)	(since C++11) (constexpr since C++26)

Prepends a copy of value to the beginning of the container.

All iterators (including the end() iterator) are invalidated. No references are invalidated.

Parameters

value	-	the value of the element to prepend
Type requirements
- If the following condition is satisfied, the behavior is undefined: 1)T is not CopyInsertable into deque. 2)T is not MoveInsertable into deque. (since C++11)

Complexity

Constant.

Exceptions

If an exception is thrown for any reason, these functions have no effect (strong exception safety guarantee).

Example

Run this code

#include <deque>#include <iomanip>#include <iostream>#include <string>   int main(){std::deque<std::string> letters;   letters.push_front("me");// overload (1)std::string s{"send"}; letters.push_front(std::move(s));// overload (2)   std::cout<<"std::deque letters holds: ";for(auto&& e : letters)std::cout<<std::quoted(e)<<' ';   std::cout<<"\nMoved-from string s holds: "<<std::quoted(s)<<'\n';}

Possible output:

std::deque letters holds: "send" "me" Moved-from string s holds: ""

See also

emplace_front (C++11)	constructs an element in-place at the beginning (public member function)
push_back	adds an element to the end (public member function)
pop_front	removes the first element (public member function)
front_inserter	creates a std::front_insert_iterator of type inferred from the argument (function template)