`<slist>`

namespace std { template<class T, class A> classslist; // TEMPLATE FUNCTIONS template<class T, class A> booloperator==( const slist<T, A>& lhs, const slist<T, A>& rhs); template<class T, class A> booloperator!=( const slist<T, A>& lhs, const slist<T, A>& rhs); template<class T, class A> booloperator<( const slist<T, A>& lhs, const slist<T, A>& rhs); template<class T, class A> booloperator>( const slist<T, A>& lhs, const slist<T, A>& rhs); template<class T, class A> booloperator<=( const slist<T, A>& lhs, const slist<T, A>& rhs); template<class T, class A> booloperator>=( const slist<T, A>& lhs, const slist<T, A>& rhs); template<class T, class A> voidswap( slist<T, A>& lhs, slist<T, A>& rhs); } // namespace std

Include the STL
standard header ** <slist>** to define the
container
template class

`slist`

and several supporting
templates.`operator!=`

template<class T, class A> booloperator!=( const slist <T, A>& lhs, const slist <T, A>& rhs);

The template function returns `!(lhs == rhs)`

.

`operator==`

template<class T, class A> booloperator==( const slist <T, A>& lhs, const slist <T, A>& rhs);

The template function overloads `operator==`

to compare
two objects of template class
`slist`

. The function returns
```
lhs.size() == rhs.size() &&
equal(lhs.
begin(), lhs.
end(), rhs.begin())
```

.

`operator<`

template<class T, class A> booloperator<( const slist <T, A>& lhs, const slist <T, A>& rhs);

The template function overloads `operator<`

to compare
two objects of template class
`slist`

. The function returns
```
lexicographical_compare(lhs.
begin(), lhs.
end(), rhs.begin(), rhs.end())
```

.

`operator<=`

template<class T, class A> booloperator<=( const slist <T, A>& lhs, const slist <T, A>& rhs);

The template function returns `!(rhs < lhs)`

.

`operator>`

template<class T, class A> booloperator>( const slist <T, A>& lhs, const slist <T, A>& rhs);

The template function returns `rhs < lhs`

.

`operator>=`

template<class T, class A> booloperator>=( const slist <T, A>& lhs, const slist <T, A>& rhs);

The template function returns `!(lhs < rhs)`

.

`slist`

```
allocator_type
· assign
· back
· begin
· clear
· const_iterator
· const_pointer
· const_reference
· difference_type
· empty
· end
· erase
· front
· get_allocator
· insert
· iterator
· slist
· max_size
· merge
· pointer
· pop_back
· pop_front
· previous
· push_back
· push_front
· reference
· remove
· remove_if
· resize
· reverse
· size
· size_type
· sort
· splice
· swap
· unique
· value_type
```

template<class T, class A = allocator<T> > classslist{ public: typedef Aallocator_type; typedef typename A::pointerpointer; typedef typename A::const_pointerconst_pointer; typedef typename A::referencereference; typedef typename A::const_referenceconst_reference; typedef typename A::value_typevalue_type; typedef T0iterator; typedef T1const_iterator; typedef T2size_type; typedef T3difference_type;slist(); explicitslist(const A& al); explicitslist(size_type n);slist(size_type n, const T& v);slist(size_type n, const T& v, const A& al);slist(const slist& x); template<class InIt>slist(InIt first, InIt last); template<class InIt>slist(InIt first, InIt last, const A& al); iteratorbegin(); const_iteratorbegin() const; iteratorend(); const_iteratorend() const; iteratorprevious(const_iterator it); const_iteratorprevious(const_iterator it) const; voidresize(size_type n); voidresize(size_type n, T x); size_typesize() const; size_typemax_size() const; boolempty() const; Aget_allocator() const; referencefront(); const_referencefront() const; referenceback(); const_referenceback() const; voidpush_front(const T& x); voidpop_front(); voidpush_back(const T& x); voidpop_back(); template<class InIt> voidassign(InIt first, InIt last); voidassign(size_type n, const T& x); iteratorinsert(iterator it, const T& x); voidinsert(iterator it, size_type n, const T& x); template<class InIt> voidinsert(iterator it, InIt first, InIt last); iteratorerase(iterator it); iteratorerase(iterator first, iterator last); voidclear(); voidswap(slist& x); voidsplice(iterator it, slist& x); voidsplice(iterator it, slist& x, iterator first); voidsplice(iterator it, slist& x, iterator first, iterator last); voidremove(const T& x); templace<class Pred> voidremove_if(Pred pr); voidunique(); template<class Pred> voidunique(Pred pr); voidmerge(slist& x); template<class Pred> voidmerge(slist& x, Pred pr); voidsort(); template<class Pred> voidsort(Pred pr); voidreverse(); };

The template class describes an object that controls a
varying-length sequence of elements of type `T`

.
The sequence is stored as a singly linked list of elements,
each containing a member of type `T`

.

The object allocates and frees storage for the sequence it controls
through a stored allocator object
of class `A`

. Such an allocator object must have
the same external interface as an object of template class
`allocator`

.
Note that the stored allocator object is *not* copied when the container
object is assigned.

**List reallocation**
occurs when a member function must insert, erase or splice elements of
the controlled sequence. In all such cases, only the following iterators
or references become
**invalid**:

- iterators that designated a position
**immediately beyond**an inserted element - iterators that designate an erased element or a position
**immediately beyond**an erased element - iterators that designate a spliced element or a position
**immediately beyond**a spliced element

All additions to the controlled sequence occur as if by calls to
`insert`

, which is the
only member function that calls the constructor
`T(const T&)`

. If such an expression throws
an exception, the container object inserts no new elements and rethrows
the exception. Thus, an object of template class `slist`

is left in a known state when such exceptions occur.

`slist::allocator_type`

typedef Aallocator_type;

The type is a synonym for the template parameter `A`

.

`slist::assign`

template<class InIt> voidassign(InIt first, InIt last); voidassign(size_type n, const T& x);

If `InIt`

is an integer type, the first member
function behaves the same as `assign((size_type)first, (T)last)`

.
Otherwise, the
first member function replaces the sequence
controlled by `*this`

with the sequence
`[first, last)`

, which must *not* overlap
the initial controlled sequence.
The second member function replaces the sequence
controlled by `*this`

with a repetition of `n`

elements of value `x`

.

`slist::back`

referenceback(); const_referenceback() const;

The member function returns a reference to the last element of the controlled sequence, which must be non-empty.

`slist::begin`

const_iteratorbegin() const; iteratorbegin();

The member function returns a forward iterator that points at the first element of the sequence (or just beyond the end of an empty sequence).

`slist::clear`

voidclear();

The member function calls
```
erase(
begin(),
end())
```

.

`slist::const_iterator`

typedef T1const_iterator;

The type describes an object that can serve as a constant
forward iterator for the controlled sequence.
It is described here as a
synonym for the implementation-defined type `T1`

.

`slist::const_pointer`

typedef typename A::const_pointerconst_pointer;

The type describes an object that can serve as a constant pointer to an element of the controlled sequence.

`slist::const_reference`

typedef typename A::const_referenceconst_reference;

The type describes an object that can serve as a constant reference to an element of the controlled sequence.

`slist::difference_type`

typedef T3difference_type;

The signed integer type describes an object that can represent the
difference between the addresses of any two elements in the controlled
sequence. It is described here as a
synonym for the implementation-defined type `T3`

.

`slist::empty`

boolempty() const;

The member function returns true for an empty controlled sequence.

`slist::end`

const_iteratorend() const; iteratorend();

The member function returns a forward iterator that points just beyond the end of the sequence.

`slist::erase`

iteratorerase(iterator it); iteratorerase(iterator first, iterator last);

The first member function removes the element of the controlled
sequence pointed to by `it`

. The second member function
removes the elements of the controlled sequence
in the range `[first, last)`

.
Both return an iterator that designates the first element remaining
beyond any elements removed, or
`end()`

if no such element exists.

Erasing `N`

elements causes
`N`

destructor calls.
Reallocation occurs,
so iterators and references become
invalid for the erased
elements and iterators become invalid for any remaining element
immediately beyond an erased element.

The member functions never throw an exception.

`slist::front`

referencefront(); const_referencefront() const;

The member function returns a reference to the first element of the controlled sequence, which must be non-empty.

`slist::get_allocator`

Aget_allocator() const;

The member function returns the stored allocator object.

`slist::insert`

iteratorinsert(iterator it, const T& x); voidinsert(iterator it, size_type n, const T& x); template<class InIt> voidinsert(iterator it, InIt first, InIt last);

Each of the member functions inserts, before the element pointed to
by `it`

in the controlled sequence, a sequence
specified by the remaining operands.
The first member function inserts
a single element with value `x`

and returns an iterator
that designates the newly inserted element. The second member function
inserts a repetition of `n`

elements of value `x`

.

If `InIt`

is an integer type, the last member
function behaves the same as `insert(it, (size_type)first, (T)last)`

.
Otherwise, the last member function inserts the sequence
`[first, last)`

, which must *not* overlap
the initial controlled sequence.

Inserting `N`

elements causes `N`

constructor calls.
Reallocation occurs,
so iterators become
invalid for any element
that was immediately beyond `it`

.

If an exception is thrown during the insertion of one or more elements, the container is left unaltered and the exception is rethrown.

`slist::iterator`

typedef T0iterator;

The type describes an object that can serve as a forward
iterator for the controlled sequence.
It is described here as a
synonym for the implementation-defined type `T0`

.

`slist::max_size`

size_typemax_size() const;

The member function returns the length of the longest sequence that the object can control.

`slist::merge`

voidmerge(slist& x); template<class Pred> voidmerge(slist& x, Pred pr);

Both member functions remove all elements from the sequence
controlled by `x`

and insert them in the controlled
sequence. Both sequences must be
ordered by the same predicate,
described below. The resulting sequence is also ordered by that
predicate.

For the iterators `Pi`

and `Pj`

designating elements at positions `i`

and `j`

, the first member function imposes the
order `!(*Pj < *Pi)`

whenever `i < j`

.
(The elements are sorted in *ascending* order.)
The second member function imposes the order
`!pr(*Pj, *Pi)`

whenever `i < j`

.

No pairs of elements in the original controlled sequence
are reversed in the resulting controlled sequence. If a pair
of elements in the resulting controlled sequence compares equal
(`!(*Pi < *Pj) && !(*Pj < *Pi)`

),
an element from the original controlled sequence appears before
an element from the sequence controlled by `x`

.

An exception occurs only if `pr`

throws an exception.
In that case, the controlled sequence is left in unspecified order
and the exception is rethrown.

`slist::pointer`

typedef typename A::pointerpointer;

The type describes an object that can serve as a pointer to an element of the controlled sequence.

`slist::pop_back`

voidpop_back();

The member function removes the last element of the controlled sequence, which must be non-empty. This operation takes time proportional to the number of elements in the controlled sequence (linear time complexity).

The member function never throws an exception.

`slist::pop_front`

voidpop_front();

The member function removes the first element of the controlled sequence, which must be non-empty.

The member function never throws an exception.

`slist::previous`

iteratorprevious(const_iterator it); const_iteratorprevious(const_iterator it) const;

The member function returns an iterator that designates the element
immediately preceding `it`

, if possible; otherwise it returns
`end()`

.
This operation takes time proportional to the number of elements
in the controlled sequence (linear time complexity).

`slist::push_back`

voidpush_back(const T& x);

The member function inserts an element with value `x`

at the end of the controlled sequence.

If an exception is thrown, the container is left unaltered and the exception is rethrown.

`slist::push_front`

voidpush_front(const T& x);

The member function inserts an element with value `x`

at the beginning of the controlled sequence.

If an exception is thrown, the container is left unaltered and the exception is rethrown.

`slist::reference`

typedef typename A::referencereference;

The type describes an object that can serve as a reference to an element of the controlled sequence.

`slist::remove`

voidremove(const T& x);

The member function removes from the controlled sequence
all elements, designated by the iterator `P`

, for which
`*P == x`

.

The member function never throws an exception.

`slist::remove_if`

templace<class Pred> voidremove_if(Pred pr);

The member function removes from the controlled sequence
all elements, designated by the iterator `P`

, for which
`pr(*P)`

is true.

An exception occurs only if `pr`

throws an exception.
In that case, the controlled sequence is left in an unspecified state
and the exception is rethrown.

`slist::resize`

voidresize(size_type n); voidresize(size_type n, T x);

The member functions both ensure that
`size()`

henceforth
returns `n`

. If it must make the controlled sequence longer,
the first member function
appends elements with value `T()`

, while the second member function
appends elements with value `x`

.
To make the controlled sequence shorter, both member functions call
`erase(begin() + n, end())`

.

`slist::reverse`

voidreverse();

The member function reverses the order in which elements appear in the controlled sequence.

`slist::size`

size_typesize() const;

The member function returns the length of the controlled sequence.

`slist::size_type`

typedef T2size_type;

The unsigned integer type describes an object that can represent the
length of any controlled sequence. It is described here as a
synonym for the implementation-defined type `T2`

.

`slist::slist`

slist(); explicitslist(const A& al); explicitslist(size_type n);slist(size_type n, const T& v);slist(size_type n, const T& v, const A& al);slist(const slist& x); template<class InIt>slist(InIt first, InIt last); template<class InIt>slist(InIt first, InIt last, const A& al);

All constructors store an
allocator object and
initialize the controlled sequence. The allocator object is the argument
`al`

, if present. For the copy constructor, it is
`x.get_allocator()`

.
Otherwise, it is `A()`

.

The first two constructors specify an
empty initial controlled sequence. The third constructor specifies
a repetition of `n`

elements of value `T()`

.
The fourth and fifth constructors specify
a repetition of `n`

elements of value `x`

.
The sixth constructor specifies a copy of the sequence controlled by
`x`

.
If `InIt`

is an integer type, the last two constructors
specify a repetition of `(size_type)first`

elements of value
`(T)last`

. Otherwise, the
last two constructors specify the sequence
`[first, last)`

.

`slist::sort`

voidsort(); template<class Pred> voidsort(Pred pr);

Both member functions order the elements in the controlled sequence by a predicate, described below.

For the iterators `Pi`

and `Pj`

designating elements at positions `i`

and `j`

, the first member function imposes the
order `!(*Pj < *Pi)`

whenever `i < j`

.
(The elements are sorted in *ascending* order.)
The member template function imposes the order
`!pr(*Pj, *Pi)`

whenever `i < j`

.
No ordered pairs of elements in the original controlled sequence
are reversed in the resulting controlled sequence.
(The sort is stable.)

An exception occurs only if `pr`

throws an exception.
In that case, the controlled sequence is left in unspecified order
and the exception is rethrown.

`slist::splice`

voidsplice(iterator it, slist& x); voidsplice(iterator it, slist& x, iterator first); voidsplice(iterator it, slist& x, iterator first, iterator last);

The first member function inserts the sequence controlled
by `x`

before the element in the controlled sequence
pointed to by `it`

. It also removes all elements from
`x`

. (`&x`

must not equal `this`

.)

The second member function removes the element pointed to by
`first`

in the sequence controlled by `x`

and
inserts it before the element in the controlled sequence
pointed to by `it`

. (If `it == first || it == ++first`

,
no change occurs.)

The third member function inserts the subrange
designated by `[first, last)`

from the sequence
controlled by `x`

before the element in the controlled sequence pointed to by `it`

.
It also removes the original subrange from the sequence controlled
by `x`

. (If `&x == this`

,
the range `[first, last)`

must not include the element
pointed to by `it`

.)

If the third member function inserts
`N`

elements, and `&x != this`

, an object of class
`iterator`

is
incremented `N`

times.
For all `splice`

member functions, If
```
get_allocator()
== str.get_allocator()
```

, no exception occurs.
Otherwise, a copy and a destructor call also
occur for each inserted element.

Iterators or references that designate
spliced elements, or that designate the first element beyond a
sequence of spliced elements, become
**invalid**.

`slist::swap`

voidswap(slist& x);

The member function swaps the controlled sequences between
`*this`

and `x`

. If
```
get_allocator()
== x.get_allocator()
```

, it does so in constant time,
it throws no exceptions, and it invalidates no references, pointers,
or iterators that designate elements in the two controlled sequences.
Otherwise, it performs a number of element assignments and constructor calls
proportional to the number of elements in the two controlled sequences.

`slist::unique`

voidunique(); template<class Pred> voidunique(Pred pr);

The first member function removes from the controlled sequence
every element that compares equal to its preceding element.
For the iterators `Pi`

and `Pj`

designating elements at positions `i`

and `j`

, the second member function removes every
element for which `i + 1 == j && pr(*Pi, *Pj)`

.

For a controlled sequence of length `N`

(> 0), the predicate `pr(*Pi, *Pj)`

is evaluated `N - 1`

times.

An exception occurs only if `pr`

throws an exception.
In that case, the controlled sequence is left in an unspecified state
and the exception is rethrown.

`slist::value_type`

typedef typename A::value_typevalue_type;

The type is a synonym for the template parameter `T`

.

`swap`

template<class T, class A> voidswap( slist <T, A>& lhs, slist <T, A>& rhs);

The template function executes
`lhs.swap(rhs)`

.

See also the
**Table of Contents** and the
**Index**.

*
Copyright © 1992-2006
by P.J. Plauger. All rights reserved.*

Last modified: 2013-12-21