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

 

C++

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Feature test macros (C++20)

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Concepts library (C++20)

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Symbols index

External libraries

 

Containers library

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array (C++11)

vector

vector<bool>

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forward_list (C++11)

list

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multimap

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unordered_set (C++11)

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stack

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span (C++20)

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std::forward_list

Member functions

forward_list::forward_list

forward_list::~forward_list

forward_list::operator=

forward_list::assign

forward_list::assign_range (C++23)

forward_list::get_allocator

Element access

forward_list::front

Iterators

forward_list::before_beginforward_list::cbefore_begin

forward_list::beginforward_list::cbegin

forward_list::endforward_list::cend

Capacity

forward_list::empty

forward_list::max_size

Modifiers

forward_list::clear

forward_list::insert_after

forward_list::emplace_after

forward_list::insert_range_after (C++23)

forward_list::erase_after

forward_list::push_front

forward_list::emplace_front

forward_list::prepend_range (C++23)

forward_list::pop_front

forward_list::resize

forward_list::swap

Operations

forward_list::merge

forward_list::splice_after

forward_list::removeforward_list::remove_if

forward_list::reverse

forward_list::unique

forward_list::sort

Non-member functions

std::swap

eraseerase_if (C++20)(C++20)

operator==operator!=operator<operator>operator<=operator>=operator<=> (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)(C++20)

Deduction guides(C++17)

 

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

Prepends the given element value to the beginning of the container.

No iterators or references are invalidated.

Parameters

value

-

the value of the element to prepend

Return value

(none)

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 <forward_list>
#include <iomanip>
#include <iostream>
#include <string>
 
int main()
{
    std::forward_list<std::string> letters;
 
    letters.push_front("abc");
    std::string s{"def"};
    letters.push_front(std::move(s));
 
    std::cout << "std::forward_list 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::forward_list letters holds: "def" "abc"
Moved-from string s holds: ""

See also

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