std::forward_list::forward_list

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

 

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

queue

priority_queue

 

std::forward_list

Member functions

forward_list::forward_list

forward_list::~forward_list

forward_list::operator=

forward_list::assign

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::erase_after

forward_list::push_front

forward_list::emplace_front

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

 

	(1)
explicit forward_list( const Allocator& alloc = Allocator() );			(since C++11) (until C++14)
forward_list() : forward_list( Allocator() ) {} explicit forward_list( const Allocator& alloc );			(since C++14)
forward_list( size_type count,               const T& value,               const Allocator& alloc = Allocator());		(2)	(since C++11)
		(3)
explicit forward_list( size_type count );				(since C++11) (until C++14)
explicit forward_list( size_type count, const Allocator& alloc = Allocator() );				(since C++14)
template< class InputIt > forward_list( InputIt first, InputIt last,               const Allocator& alloc = Allocator() );			(4)	(since C++11)
forward_list( const forward_list& other );			(5)	(since C++11)
forward_list( const forward_list& other, const Allocator& alloc );			(5)	(since C++11)
forward_list( forward_list&& other )			(6)	(since C++11)
forward_list( forward_list&& other, const Allocator& alloc );			(6)	(since C++11)
forward_list( std::initializer_list<T> init,               const Allocator& alloc = Allocator() );			(7)	(since C++11)

Constructs new container from a variety of data sources and optionally using user supplied allocator alloc.

1) Default constructor. Constructs empty container.

2) Constructs the container with count copies of elements with value value.

3) Constructs the container with count value-initialized instances of T. No copies are made.

4) Constructs the container with the contents of the range [first, last). This constructor does not participate in overload resolution if InputIt does not satisfy InputIterator, to avoid ambiguity with the overload 2 (since C++11)

5) Copy constructor. Constructs the container with the copy of the contents of other. If alloc is not provided, allocator is obtained by calling std::allocator_traits<allocator_type>::select_on_container_copy_construction(other).

6) Move constructor. Constructs the container with the contents of other using move semantics. If alloc is not provided, allocator is obtained by move-construction from the allocator belonging to other.

7) Constructs the container with the contents of the initializer list init.

Parameters

alloc	-	allocator to use for all memory allocations of this container
count	-	the size of the container
value	-	the value to initialize elements of the container with
first, last	-	the range to copy the elements from
other	-	another container to be used as source to initialize the elements of the container with
init	-	initializer list to initialize the elements of the container with
Type requirements
- Allocator must meet the requirements of Allocator.
- InputIt must meet the requirements of InputIterator.

Complexity

1) Constant

2-3) Linear in count

4) Linear in distance between first and last

5) Linear in size of other

6) Constant. If alloc is given and alloc != other.get_allocator(), then linear.

7) Linear in size of init

Example

Run this code

#include <forward_list>
#include <string>
#include <iostream>
 
template<typename T>
std::ostream& operator<<(std::ostream& s, const std::forward_list<T>& v) {
    s.put('[');
    char comma[3] = {'\0', ' ', '\0'};
    for (const auto& e : v) {
        s << comma << e;
        comma[0] = ',';
    }
    return s << ']';
}
 
int main() 
{
    // c++11 initializer list syntax:
    std::forward_list<std::string> words1 {"the", "frogurt", "is", "also", "cursed"};
    std::cout << "words1: " << words1 << '\n';
 
    // words2 == words1
    std::forward_list<std::string> words2(words1.begin(), words1.end());
    std::cout << "words2: " << words2 << '\n';
 
    // words3 == words1
    std::forward_list<std::string> words3(words1);
    std::cout << "words3: " << words3 << '\n';
 
    // words4 is {"Mo", "Mo", "Mo", "Mo", "Mo"}
    std::forward_list<std::string> words4(5, "Mo");
    std::cout << "words4: " << words4 << '\n';
}

Output:

words1: [the, frogurt, is, also, cursed]
words2: [the, frogurt, is, also, cursed]
words3: [the, frogurt, is, also, cursed]
words4: [Mo, Mo, Mo, Mo, Mo]

See also

assign	assigns values to the container (public member function)
operator=	assigns values to the container (public member function)