std::forward_list - Man Page

typedef _Alloc allocator_type
typedef _Base::const_iterator const_iterator
typedef _Alloc_traits::const_pointer const_pointer
typedef const value_type & const_reference
typedef std::ptrdiff_t difference_type
typedef _Base::iterator iterator
typedef _Alloc_traits::pointer pointer
typedef value_type & reference
typedef std::size_t size_type
typedef _Tp value_type

forward_list ()=default
Creates a forward_list with no elements.
template<typename _InputIterator , typename  = std::_RequireInputIter<_InputIterator>> forward_list (_InputIterator __first, _InputIterator __last, const _Alloc &__al=_Alloc())
Builds a forward_list from a range.
forward_list (const _Alloc &__al) noexcept
Creates a forward_list with no elements.
forward_list (const forward_list &__list)
The forward_list copy constructor.
forward_list (const forward_list &__list, const __type_identity_t< _Alloc > &__al)
Copy constructor with allocator argument.
forward_list (forward_list &&)=default
The forward_list move constructor.
forward_list (forward_list &&__list, const __type_identity_t< _Alloc > &__al) noexcept(_Node_alloc_traits::_S_always_equal())
Move constructor with allocator argument.
forward_list (size_type __n, const _Alloc &__al=_Alloc())
Creates a forward_list with default constructed elements.
forward_list (size_type __n, const _Tp &__value, const _Alloc &__al=_Alloc())
Creates a forward_list with copies of an exemplar element.
forward_list (std::initializer_list< _Tp > __il, const _Alloc &__al=_Alloc())
Builds a forward_list from an initializer_list.
~forward_list () noexcept
The forward_list dtor.
template<typename _InputIterator , typename  = std::_RequireInputIter<_InputIterator>> void assign (_InputIterator __first, _InputIterator __last)
Assigns a range to a forward_list.
void assign (size_type __n, const _Tp &__val)
Assigns a given value to a forward_list.
void assign (std::initializer_list< _Tp > __il)
Assigns an initializer_list to a forward_list.
const_iterator before_begin () const noexcept
iterator before_begin () noexcept
const_iterator begin () const noexcept
iterator begin () noexcept
const_iterator cbefore_begin () const noexcept
const_iterator cbegin () const noexcept
const_iterator cend () const noexcept
void clear () noexcept
Erases all the elements.
template<typename... _Args> iterator emplace_after (const_iterator __pos, _Args &&... __args)
Constructs object in forward_list after the specified iterator.
template<typename... _Args> reference emplace_front (_Args &&... __args)
Constructs object in forward_list at the front of the list.
bool empty () const noexcept
const_iterator end () const noexcept
iterator end () noexcept
iterator erase_after (const_iterator __pos)
Removes the element pointed to by the iterator following pos.
iterator erase_after (const_iterator __pos, const_iterator __last)
Remove a range of elements.
reference front ()
const_reference front () const
allocator_type get_allocator () const noexcept
Get a copy of the memory allocation object.
template<typename _InputIterator , typename  = std::_RequireInputIter<_InputIterator>> iterator insert_after (const_iterator __pos, _InputIterator __first, _InputIterator __last)
Inserts a range into the forward_list.
iterator insert_after (const_iterator __pos, _Tp &&__val)
iterator insert_after (const_iterator __pos, const _Tp &__val)
Inserts given value into forward_list after specified iterator.
iterator insert_after (const_iterator __pos, size_type __n, const _Tp &__val)
Inserts a number of copies of given data into the forward_list.
iterator insert_after (const_iterator __pos, std::initializer_list< _Tp > __il)
Inserts the contents of an initializer_list into forward_list after the specified iterator.
size_type max_size () const noexcept
void merge (forward_list &&__list)
Merge sorted lists.
template<typename _Comp > void merge (forward_list &&__list, _Comp __comp)
Merge sorted lists according to comparison function.
void merge (forward_list &__list)
template<typename _Comp > void merge (forward_list &__list, _Comp __comp)
forward_list & operator= (const forward_list &__list)
The forward_list assignment operator.
forward_list & operator= (forward_list &&__list) noexcept(_Node_alloc_traits::_S_nothrow_move())
The forward_list move assignment operator.
forward_list & operator= (std::initializer_list< _Tp > __il)
The forward_list initializer list assignment operator.
void pop_front ()
Removes first element.
void push_front (_Tp &&__val)
void push_front (const _Tp &__val)
Add data to the front of the forward_list.
__remove_return_type remove (const _Tp &__val)
Remove all elements equal to value.
template<typename _Pred > __remove_return_type remove_if (_Pred __pred)
Remove all elements satisfying a predicate.
template<typename _Pred > auto remove_if (_Pred __pred) -> __remove_return_type
void resize (size_type __sz)
Resizes the forward_list to the specified number of elements.
void resize (size_type __sz, const value_type &__val)
Resizes the forward_list to the specified number of elements.
void reverse () noexcept
Reverse the elements in list.
void sort ()
Sort the elements of the list.
template<typename _Comp > void sort (_Comp __comp)
Sort the forward_list using a comparison function.
void splice_after (const_iterator __pos, forward_list &&__list) noexcept
Insert contents of another forward_list.
void splice_after (const_iterator __pos, forward_list &&__list, const_iterator __i) noexcept
Insert element from another forward_list.
void splice_after (const_iterator __pos, forward_list &__list) noexcept
void splice_after (const_iterator __pos, forward_list &__list, const_iterator __i) noexcept
void swap (forward_list &__list) noexcept
Swaps data with another forward_list.
__remove_return_type unique ()
Remove consecutive duplicate elements.
template<typename _BinPred > __remove_return_type unique (_BinPred __binary_pred)
Remove consecutive elements satisfying a predicate.
template<typename _BinPred > auto unique (_BinPred __binary_pred) -> __remove_return_type

void splice_after (const_iterator __pos, forward_list &&, const_iterator __before, const_iterator __last) noexcept
Insert range from another forward_list.
void splice_after (const_iterator __pos, forward_list &, const_iterator __before, const_iterator __last) noexcept
Insert range from another forward_list.

class std::forward_list< _Tp, _Alloc >"A standard container with linear time access to elements, and fixed time insertion/deletion at any point in the sequence.

Since

C++11

Template Parameters

Meets the requirements of a container, a sequence, including the optional sequence requirements with the exception of at and operator[].

This is a singly linked list. Traversal up the list requires linear time, but adding and removing elements (or nodes) is done in constant time, regardless of where the change takes place. Unlike std::vector and std::deque, random-access iterators are not provided, so subscripting ( [] ) access is not allowed. For algorithms which only need sequential access, this lack makes no difference.

Also unlike the other standard containers, std::forward_list provides specialized algorithms unique to linked lists, such as splicing, sorting, and in-place reversal.

Creates a forward_list with no elements.

Creates a forward_list with no elements.

Parameters

Copy constructor with allocator argument.

Parameters

References std::forward_list< _Tp, _Alloc >::begin(), and std::forward_list< _Tp, _Alloc >::end().

Move constructor with allocator argument.

Parameters

Creates a forward_list with default constructed elements.

Parameters

This constructor creates the forward_list with __n default constructed elements.

Creates a forward_list with copies of an exemplar element.

Parameters

This constructor fills the forward_list with __n copies of __value.

Builds a forward_list from a range.

Parameters

Create a forward_list consisting of copies of the elements from [__first,__last). This is linear in N (where N is distance(__first,__last)).

The forward_list copy constructor.

Parameters

References std::forward_list< _Tp, _Alloc >::begin(), and std::forward_list< _Tp, _Alloc >::end().

The forward_list move constructor.

Parameters

The newly-created forward_list contains the exact contents of the moved instance. The contents of the moved instance are a valid, but unspecified forward_list.

Builds a forward_list from an initializer_list.

Parameters

Create a forward_list consisting of copies of the elements in the initializer_list __il. This is linear in __il.size().

The forward_list dtor.

Assigns a range to a forward_list.

Parameters

This function fills a forward_list with copies of the elements in the range [__first,__last).

Note that the assignment completely changes the forward_list and that the number of elements of the resulting forward_list is the same as the number of elements assigned.

Referenced by std::forward_list< _Tp, _Alloc >::assign(), and std::forward_list< _Tp, _Alloc >::operator=().

Assigns a given value to a forward_list.

Parameters

This function fills a forward_list with __n copies of the given value. Note that the assignment completely changes the forward_list, and that the resulting forward_list has __n elements.

Assigns an initializer_list to a forward_list.

Parameters

Replace the contents of the forward_list with copies of the elements in the initializer_list __il. This is linear in il.size().

References std::forward_list< _Tp, _Alloc >::assign().

Returns a read-only (constant) iterator that points before the first element in the forward_list. Iteration is done in ordinary element order.

Returns a read/write iterator that points before the first element in the forward_list. Iteration is done in ordinary element order.

Referenced by std::forward_list< _Tp, _Alloc >::insert_after(), and std::forward_list< _Tp, _Alloc >::insert_after().

Returns a read-only (constant) iterator that points to the first element in the forward_list. Iteration is done in ordinary element order.

Returns a read/write iterator that points to the first element in the forward_list. Iteration is done in ordinary element order.

Referenced by std::forward_list< _Tp, _Alloc >::forward_list(), and std::forward_list< _Tp, _Alloc >::forward_list().

Returns a read-only (constant) iterator that points before the first element in the forward_list. Iteration is done in ordinary element order.

Referenced by std::forward_list< _Tp, _Alloc >::emplace_front(), std::forward_list< _Tp, _Alloc >::push_front(), and std::forward_list< _Tp, _Alloc >::remove().

Returns a read-only (constant) iterator that points to the first element in the forward_list. Iteration is done in ordinary element order.

Referenced by std::forward_list< _Tp, _Alloc >::operator=(), and std::operator==().

Returns a read-only (constant) iterator that points one past the last element in the forward_list. Iteration is done in ordinary element order.

Referenced by std::forward_list< _Tp, _Alloc >::operator=(), and std::operator==().

Erases all the elements. Note that this function only erases the elements, and that if the elements themselves are pointers, the pointed-to memory is not touched in any way. Managing the pointer is the user's responsibility.

Constructs object in forward_list after the specified iterator.

Parameters

Returns

An iterator that points to the inserted data.

This function will insert an object of type T constructed with T(std::forward<Args>(args)...) after the specified location. Due to the nature of a forward_list this operation can be done in constant time, and does not invalidate iterators and references.

References std::forward().

Constructs object in forward_list at the front of the list.

Parameters

This function will insert an object of type Tp constructed with Tp(std::forward<Args>(args)...) at the front of the list Due to the nature of a forward_list this operation can be done in constant time, and does not invalidate iterators and references.

References std::forward_list< _Tp, _Alloc >::cbefore_begin(), std::forward(), and std::forward_list< _Tp, _Alloc >::front().

Returns true if the forward_list is empty. (Thus begin() would equal end().)

Referenced by std::forward_list< _Tp, _Alloc >::insert_after().

Returns a read-only iterator that points one past the last element in the forward_list. Iteration is done in ordinary element order.

Returns a read/write iterator that points one past the last element in the forward_list. Iteration is done in ordinary element order.

Referenced by std::forward_list< _Tp, _Alloc >::forward_list(), std::forward_list< _Tp, _Alloc >::forward_list(), std::forward_list< _Tp, _Alloc >::insert_after(), and std::forward_list< _Tp, _Alloc >::insert_after().

Removes the element pointed to by the iterator following pos.

Parameters

Returns

An iterator pointing to the element following the one that was erased, or end() if no such element exists.

This function will erase the element at the given position and thus shorten the forward_list by one.

Due to the nature of a forward_list this operation can be done in constant time, and only invalidates iterators/references to the element being removed. The user is also cautioned that this function only erases the element, and that if the element is itself a pointer, the pointed-to memory is not touched in any way. Managing the pointer is the user's responsibility.

Remove a range of elements.

Parameters

Returns

This function will erase the elements in the range (__pos,__last) and shorten the forward_list accordingly.

This operation is linear time in the size of the range and only invalidates iterators/references to the element being removed. The user is also cautioned that this function only erases the elements, and that if the elements themselves are pointers, the pointed-to memory is not touched in any way. Managing the pointer is the user's responsibility.

Returns a read/write reference to the data at the first element of the forward_list.

Referenced by std::forward_list< _Tp, _Alloc >::emplace_front().

Returns a read-only (constant) reference to the data at the first element of the forward_list.

Get a copy of the memory allocation object.

Inserts a range into the forward_list.

Parameters

Returns

An iterator pointing to the last inserted element or __pos if __first == __last.

This function will insert copies of the data in the range [__first,__last) into the forward_list after the location specified by __pos.

This operation is linear in the number of elements inserted and does not invalidate iterators and references.

References std::forward_list< _Tp, _Alloc >::before_begin(), std::forward_list< _Tp, _Alloc >::empty(), and std::forward_list< _Tp, _Alloc >::end().

Inserts given value into forward_list after specified iterator.

Parameters

Returns

An iterator that points to the inserted data.

This function will insert a copy of the given value after the specified location. Due to the nature of a forward_list this operation can be done in constant time, and does not invalidate iterators and references.

Referenced by std::forward_list< _Tp, _Alloc >::insert_after().

Inserts a number of copies of given data into the forward_list.

Parameters

Returns

An iterator pointing to the last inserted copy of val or pos if n == 0.

This function will insert a specified number of copies of the given data after the location specified by pos.

This operation is linear in the number of elements inserted and does not invalidate iterators and references.

References std::forward_list< _Tp, _Alloc >::before_begin(), and std::forward_list< _Tp, _Alloc >::end().

Inserts the contents of an initializer_list into forward_list after the specified iterator.

Parameters

Returns

An iterator pointing to the last inserted element or __pos if __il is empty.

This function will insert copies of the data in the initializer_list __il into the forward_list before the location specified by __pos.

This operation is linear in the number of elements inserted and does not invalidate iterators and references.

References std::forward_list< _Tp, _Alloc >::insert_after().

Returns the largest possible number of elements of forward_list.

References std::allocator_traits< _Alloc >::max_size().

Merge sorted lists.

Parameters

Assumes that both list and this list are sorted according to operator<(). Merges elements of __list into this list in sorted order, leaving __list empty when complete. Elements in this list precede elements in __list that are equal.

References std::forward_list< _Tp, _Alloc >::merge(), and std::move().

Referenced by std::forward_list< _Tp, _Alloc >::merge().

Merge sorted lists according to comparison function.

Parameters

Assumes that both __list and this list are sorted according to comp. Merges elements of __list into this list in sorted order, leaving __list empty when complete. Elements in this list precede elements in __list that are equivalent according to comp().

References std::__addressof(), and std::move().

The forward_list assignment operator.

Parameters

All the elements of __list are copied.

Whether the allocator is copied depends on the allocator traits.

References std::__addressof(), std::forward_list< _Tp, _Alloc >::cbegin(), and std::forward_list< _Tp, _Alloc >::cend().

The forward_list move assignment operator.

Parameters

The contents of __list are moved into this forward_list (without copying, if the allocators permit it).

Afterwards __list is a valid, but unspecified forward_list

Whether the allocator is moved depends on the allocator traits.

References std::move().

The forward_list initializer list assignment operator.

Parameters

Replace the contents of the forward_list with copies of the elements in the initializer_list __il. This is linear in __il.size().

References std::forward_list< _Tp, _Alloc >::assign().

Removes first element. This is a typical stack operation. It shrinks the forward_list by one. Due to the nature of a forward_list this operation can be done in constant time, and only invalidates iterators/references to the element being removed.

Note that no data is returned, and if the first element's data is needed, it should be retrieved before pop_front() is called.

Add data to the front of the forward_list.

Parameters

This is a typical stack operation. The function creates an element at the front of the forward_list and assigns the given data to it. Due to the nature of a forward_list this operation can be done in constant time, and does not invalidate iterators and references.

References std::forward_list< _Tp, _Alloc >::cbefore_begin().

Remove all elements equal to value.

Parameters

Removes every element in the list equal to __val. Remaining elements stay in list order. Note that this function only erases the elements, and that if the elements themselves are pointers, the pointed-to memory is not touched in any way. Managing the pointer is the user's responsibility.

References std::forward_list< _Tp, _Alloc >::cbefore_begin(), and std::forward_list< _Tp, _Alloc >::splice_after().

Remove all elements satisfying a predicate.

Parameters

Removes every element in the list for which the predicate returns true. Remaining elements stay in list order. Note that this function only erases the elements, and that if the elements themselves are pointers, the pointed-to memory is not touched in any way. Managing the pointer is the user's responsibility.

Resizes the forward_list to the specified number of elements.

Parameters

This function will resize the forward_list to the specified number of elements. If the number is smaller than the forward_list's current number of elements the forward_list is truncated, otherwise the forward_list is extended and the new elements are default constructed.

References std::end().

Resizes the forward_list to the specified number of elements.

Parameters

This function will resize the forward_list to the specified number of elements. If the number is smaller than the forward_list's current number of elements the forward_list is truncated, otherwise the forward_list is extended and new elements are populated with given data.

References std::end().

Reverse the elements in list. Reverse the order of elements in the list in linear time.

Sort the elements of the list. Sorts the elements of this list in NlogN time. Equivalent elements remain in list order.

References std::forward_list< _Tp, _Alloc >::sort().

Referenced by std::forward_list< _Tp, _Alloc >::sort().

Sort the forward_list using a comparison function. Sorts the elements of this list in NlogN time. Equivalent elements remain in list order.

Insert range from another forward_list.

Parameters

Removes elements in the range (__before,__last) and inserts them after __pos in constant time.

Undefined if __pos is in (__before,__last).

Insert contents of another forward_list.

Parameters

The elements of list are inserted in constant time after the element referenced by pos. list becomes an empty list.

Requires this != x.

Referenced by std::forward_list< _Tp, _Alloc >::remove().

Insert element from another forward_list.

Parameters

Removes the element in list list referenced by i and inserts it into the current list after pos.

Insert range from another forward_list.

Parameters

Removes elements in the range (__before,__last) and inserts them after __pos in constant time.

Undefined if __pos is in (__before,__last).

Swaps data with another forward_list.

Parameters

This exchanges the elements between two lists in constant time. Note that the global std::swap() function is specialized such that std::swap(l1,l2) will feed to this function.

Whether the allocators are swapped depends on the allocator traits.

Remove consecutive duplicate elements. For each consecutive set of elements with the same value, remove all but the first one. Remaining elements stay in list order. Note that this function only erases the elements, and that if the elements themselves are pointers, the pointed-to memory is not touched in any way. Managing the pointer is the user's responsibility.

References std::forward_list< _Tp, _Alloc >::unique().

Referenced by std::forward_list< _Tp, _Alloc >::unique().

Remove consecutive elements satisfying a predicate.

Parameters

For each consecutive set of elements [first,last) that satisfy predicate(first,i) where i is an iterator in [first,last), remove all but the first one. Remaining elements stay in list order. Note that this function only erases the elements, and that if the elements themselves are pointers, the pointed-to memory is not touched in any way. Managing the pointer is the user's responsibility.