Boost.MultiIndex Sequenced indices reference"boost/multi_index/sequenced_index_fwd.hpp" synopsis"boost/multi_index/sequenced_index.hpp" synopsis
"boost/multi_index/sequenced_index_fwd.hpp" synopsisnamespace boost{ namespace multi_index{ // sequenced index specifier template<typename TagList=tag<> > struct sequenced; // indices namespace detail{ template<implementation defined> class index class name implementation defined; } // namespace boost::multi_index::detail } // namespace boost::multi_index } // namespace boost
sequenced_index_fwd.hpp provides forward declarations for the
sequenced index specifier and
its associated sequenced index class.
"boost/multi_index/sequenced_index.hpp" synopsisnamespace boost{ namespace multi_index{ // sequenced index specifier template<typename TagList=tag<> > struct sequenced; // indices namespace detail{ template<implementation defined> class index class name implementation defined; // index comparison: // OP is any of ==,<,!=,>,>=,<= template<arg set 1,arg set 2> bool operator OP( const index class name<arg set 1>& x,const index class name<arg set 2>& y); // index specialized algorithms: template<implementation defined> void swap(index class name& x,index class name& y); } // namespace boost::multi_index::detail } // namespace boost::multi_index } // namespace boost
sequenced index specifier
This index specifier allows for insertion of a sequenced index.
template<typename TagList=tag<> > struct sequenced;
If provided, TagList must be an instantiation of
tag.
Sequenced indices are modeled after the semantics of a bidirectional list
like std::list. Elements in a sequenced index are by default
sorted according to their order of insertion: this means that new elements
inserted through a different index of the multi_index_container are appended
to the end of the sequenced index. Additionally, the index allows for free
reordering of elements in the same vein as std::list does. Validity
of iterators and references to elements is preserved in all operations.
There are a number of differences with respect to std::lists:
Assignable (like any other index.)std::list, insertions into a sequenced index
may fail due to clashings with other indices. This alters the semantics
of the operations provided with respect to their analogues in
std::list.
replace and
modify member functions.
Reversible Container,
Front Insertion Sequence and
Back Insertion Sequence. We only provide descriptions
of those types and operations that are either not present in the
concepts modeled or do not exactly conform to the requirements for these
types of containers.
namespace boost{ namespace multi_index{ namespace detail{ template<implementation defined: dependent on types Value, Allocator, TagList> class name is implementation defined { public: // types: typedef typename node_type::value_type value_type; typedef tuples::null_type ctor_args; typedef typename Allocator allocator_type; typedef typename allocator_type::reference reference; typedef typename allocator_type::const_reference const_reference; typedef implementation defined iterator; typedef implementation defined const_iterator; typedef std::size_t size_type; typedef std::ptrdiff_t difference_type; typedef typename allocator_type::pointer pointer; typedef typename allocator_type::const_pointer const_pointer; typedef equivalent to std::reverse_iterator<iterator> reverse_iterator; typedef equivalent to std::reverse_iterator<const_iterator> const_reverse_iterator; // construct/copy/destroy: index class name& operator=(const index class name& x); template <class InputIterator> void assign(InputIterator first,InputIterator last); void assign(size_type n,const value_type& value); allocator_type get_allocator()const; // iterators: iterator begin(); const_iterator begin()const; iterator end(); const_iterator end()const; reverse_iterator rbegin(); const_reverse_iterator rbegin()const; reverse_iterator rend(); const_reverse_iterator rend()const; // capacity: bool empty()const; size_type size()const; size_type max_size()const; void resize(size_type n,const value_type& x=value_type()); // access: const_reference front()const; const_reference back()const; // modifiers: std::pair<iterator,bool> push_front(const value_type& x); void pop_front(); std::pair<iterator,bool> push_back(const value_type& x); void pop_back(); std::pair<iterator,bool> insert(iterator position,const value_type& x); void insert(iterator position,size_type n,const value_type& x); template<typename InputIterator> void insert(iterator position,InputIterator first,InputIterator last); iterator erase(iterator position); iterator erase(iterator first,iterator last); bool replace(iterator position,const value_type& x); template<typename Modifier> bool modify(iterator position,Modifier mod); void swap(index class name& x); void clear(); // list operations: void splice(iterator position,index class name& x); void splice(iterator position,index class name& x,iterator i); void splice( iterator position,index class name& x,iterator first,iterator last); void remove(const value_type& value); template<typename Predicate> void remove_if(Predicate pred); void unique(); template <class BinaryPredicate> void unique(BinaryPredicate binary_pred); void merge(index class name& x); template <typename Compare> void merge(index class name& x,Compare comp); void sort(); template <typename Compare> void sort(Compare comp); void reverse(); // rearrange operations: void relocate(iterator position,iterator i); void relocate(iterator position,iterator first,iterator last); template<typename InputIterator> void rearrange(InputIterator first); } // index comparison: template<arg set 1,arg set 2> bool operator==( const index class name<arg set 1>& x, const index class name<arg set 2>& y) { return x.size()==y.size()&&std::equal(x.begin(),x.end(),y.begin()); } template<arg set 1,arg set 2> bool operator<( const index class name<arg set 1>& x, const index class name<arg set 2>& y) { return std::lexicographical_compare(x.begin(),x.end(),y.begin(),y.end()); } template<arg set 1,arg set 2> bool operator!=( const index class name<arg set 1>& x, const index class name<arg set 2>& y) { return !(x==y); } template<arg set 1,arg set 2> bool operator>( const index class name<arg set 1>& x ,const index class name<arg set 2>& y) { return y<x; } template<arg set 1,arg set 2> bool operator>=( const index class name<arg set 1>& x, const index class name<arg set 2>& y) { return !(x<y); } template<arg set 1,arg set 2> bool operator<=( const index class name<arg set 1>& x, const index class name<arg set 2>& y) { return !(x>y); } // index specialized algorithms: template<implementation defined> void swap(index class name& x,index class name& y); } // namespace boost::multi_index::detail } // namespace boost::multi_index } // namespace boost
Here and in the descriptions of operations of sequenced indices, we adopt the scheme outlined in the complexity signature section. The complexity signature of sequenced indices is:
c(n)=n*log(n),i(n)=1 (constant),h(n)=1 (constant),d(n)=1 (constant),r(n)=1 (constant),m(n)=1 (constant).Sequenced indices are instantiated internally to multi_index_container
and specified by means of
indexed_by with the sequenced
index specifier. Instantiations are dependent on the following types:
Value from multi_index_container,Allocator from multi_index_container,TagList from the index specifier (if provided).TagList must be an instantiation of
tag.
As explained in the index concepts section, indices do not have public constructors or destructors. Assignment, on the other hand, is provided.
index class name& operator=(const index class name& x);
Effects:wherea=b;aandbare themulti_index_containerobjects to which*thisandxbelong, respectively.
Returns:*this.
template <class InputIterator>
void assign(InputIterator first,InputIterator last);
Requires:InputIteratoris a model ofInput Iteratorover elements of typevalue_typeor a type convertible tovalue_type.firstandlastare not iterators into any index of themulti_index_containerto which this index belongs.lastis reachable fromfirst. Effects:clear(); insert(end(),first,last);
void assign(size_type n,const value_type& value);
Effects:clear(); for(size_type i=0;i<n;++n)push_back(v);
void resize(size_type n,const value_type& x=value_type());
Effects:Note: If an expansion is requested, the size of the index is not guaranteed to beif(n>size())insert(end(),n-size(),x); else if(n<size()){ iterator it=begin(); std::advance(it,n); erase(it,end()); }nafter this operation (other indices may ban insertions.)
std::pair<iterator,bool> push_front(const value_type& x);
Effects: Insertsxat the beginning of the sequence if no other index of themulti_index_containerbans the insertion.
Returns: The return value is a pairp.p.secondistrueif and only if insertion took place. On successful insertion,p.firstpoints to the element inserted; otherwise,p.firstpoints to an element that caused the insertion to be banned. Note that more than one element can be causing insertion not to be allowed.
Complexity:O(I(n)).
Exception safety: Strong.
std::pair<iterator,bool> push_back(const value_type& x);
Effects: Insertsxat the end of the sequence if no other index of themulti_index_containerbans the insertion.
Returns: The return value is a pairp.p.secondistrueif and only if insertion took place. On successful insertion,p.firstpoints to the element inserted; otherwise,p.firstpoints to an element that caused the insertion to be banned. Note that more than one element can be causing insertion not to be allowed.
Complexity:O(I(n)).
Exception safety: Strong.
std::pair<iterator,bool> insert(iterator position,const value_type& x);
Requires:positionis a valid iterator of the index. Effects: Insertsxbeforepositionif insertion is allowed by all other indices of themulti_index_container.
Returns: The return value is a pairp.p.secondistrueif and only if insertion took place. On successful insertion,p.firstpoints to the element inserted; otherwise,p.firstpoints to an element that caused the insertion to be banned. Note that more than one element can be causing insertion not to be allowed.
Complexity:O(I(n)).
Exception safety: Strong.
void insert(iterator position,size_type n,const value_type& x);
Requires:positionis a valid iterator of the index. Effects:for(size_type i=0;i<n;++i)insert(position,x);
template<typename InputIterator>
void insert(iterator position,InputIterator first,InputIterator last);
Requires:positionis a valid iterator of the index.InputIteratoris a model ofInput Iteratorover elements of typevalue_typeor a type convertible tovalue_type.firstandlastare not iterators into any index of themulti_index_containerto which this index belongs.lastis reachable fromfirst. Effects:Complexity:while(first!=last)insert(position,*first++);O(m*I(n+m)), wheremis the number of elements in [first,last).
Exception safety: Basic.
iterator erase(iterator position);
Requires:positionis a valid dereferenceable iterator of the index. Effects: Deletes the element pointed to byposition.
Returns: An iterator pointing to the element immediately following the one that was deleted, orend()if no such element exists.
Complexity:O(D(n)).
Exception safety:nothrow.
iterator erase(iterator first,iterator last);
Requires: [first,last) is a valid range of the index.
Effects: Deletes the elements in [first,last).
Returns:last.
Complexity:O(m*D(n)), wheremis the number of elements in [first,last).
Exception safety:nothrow.
bool replace(iterator position,const value_type& x);
Requires:positionis a valid dereferenceable iterator of the index. Effects: Assigns the valuexto the element pointed to bypositioninto themulti_index_containerto which the index belongs if replacing is allowed by all other indices of themulti_index_container.
Postconditions: Validity ofpositionis preserved in all cases.
Returns:trueif the replacement took place,falseotherwise.
Complexity:O(R(n)).
Exception safety: Strong. If an exception is thrown by some user-provided operation themulti_index_containerto which the index belongs remains in its original state.
template<typename Modifier> bool modify(iterator position,Modifier mod);
Requires:Modifieris a model ofUnary Functionaccepting arguments of typevalue_type&.positionis a valid dereferenceable iterator of the index. Effects: Callsmod(e)whereeis the element pointed to bypositionand rearranges*positioninto all the indices of themulti_index_container. Rearrangement on sequenced indices does not change the position of the element with respect to the index; rearrangement on other indices may or might not suceed. If the rearrangement fails, the element is erased.
Postconditions: Validity ofpositionis preserved if the operation succeeds.
Returns:trueif the operation succeeded,falseotherwise.
Complexity:O(M(n)).
Exception safety: Basic. If an exception is thrown by some user-provided operation (except possiblymod), then the element pointed to bypositionis erased.
Sequenced indices provide the full set of list operations found in
std::list; the semantics of these member functions, however,
differ from that of std::list in some cases as insertions
might not succeed due to banning by other indices. Similarly, the complexity
of the operations may depend on the other indices belonging to the
same multi_index_container.
void splice(iterator position,index class name& x);
Requires:positionis a valid iterator of the index.&x!=this. Effects: Inserts the contents ofxbeforeposition, in the same order as they were inx. Those elements succesfully inserted are erased fromx.
Complexity:O(x.size()*I(n+x.size()) + x.size()*D(x.size())).
Exception safety: Basic.
void splice(iterator position,index class name& x,iterator i);
Requires:positionis a valid iterator of the index.iis a valid dereferenceable iteratorx.
Effects: Inserts the element pointed to byibeforeposition: if insertion is succesful, the element is erased fromx. In the special case&x==this, no copy or deletion is performed, and the operation is always succesful. Ifposition==i, no operation is performed.
Postconditions: If&x==this, no iterator or reference is invalidated.
Complexity: If&x==this, constant; otherwiseO(I(n) + D(n)).
Exception safety: If&x==this,nothrow; otherwise, strong.
void splice(iterator position,index class name& x,iterator first,iterator last);
Requires:positionis a valid iterator of the index.firstandlastare valid iterators ofx.lastis reachable fromfirst.positionis not in the range [first,last).
Effects: For each element in the range [first,last), insertion is tried beforeposition; if the operation is succesful, the element is erased fromx. In the special case&x==this, no copy or deletion is performed, and insertions are always succesful.
Postconditions: If&x==this, no iterator or reference is invalidated.
Complexity: If&x==this, constant; otherwiseO(m*I(n+m) + m*D(x.size()))wheremis the number of elements in [first,last).
Exception safety: If&x==this,nothrow; otherwise, basic.
void remove(const value_type& value);
Effects: Erases all elements of the index which compare equal tovalue.
Complexity:O(n + m*D(n)), wheremis the number of elements erased.
Exception safety: Basic.
template<typename Predicate> void remove_if(Predicate pred);
Effects: Erases all elementsxof the index for whichpred(x)holds.
Complexity:O(n + m*D(n)), wheremis the number of elements erased.
Exception safety: Basic.
void unique();
Effects: Eliminates all but the first element from every consecutive group of equal elements referred to by the iteratoriin the range [first+1,last) for which*i==*(i-1).
Complexity:O(n + m*D(n)), wheremis the number of elements erased.
Exception safety: Basic.
template <class BinaryPredicate> void unique(BinaryPredicate binary_pred);
Effects: Eliminates all but the first element from every consecutive group of elements referred to by the iteratoriin the range [first+1,last) for whichbinary_pred(*i,*(i-1))holds.
Complexity:O(n + m*D(n)), wheremis the number of elements erased.
Exception safety: Basic.
void merge(index class name& x);
Requires:std::less<value_type>is aStrict Weak Orderingovervalue_type. Both the index andxare sorted according tostd::less<value_type>.
Effects: Attempts to insert every element ofxinto the corresponding position of the index (according to the order). Elements successfully inserted are erased fromx. The resulting sequence is stable, i.e. equivalent elements of either container preserve their relative position. In the special case&x==this, no operation is performed.
Postconditions: Elements in the index and remaining elements inxare sorted. Validity of iterators to the index and of non-erased elements ofxreferences is preserved.
Complexity: If&x==this, constant; otherwiseO(n + x.size()*I(n+x.size()) + x.size()*D(x.size())).
Exception safety: If&x==this,nothrow; otherwise, basic.
template <typename Compare> void merge(index class name& x,Compare comp);
Requires:Compareis aStrict Weak Orderingovervalue_type. Both the index andxare sorted according tocomp.
Effects: Attempts to insert every element ofxinto the corresponding position of the index (according tocomp). Elements successfully inserted are erased fromx. The resulting sequence is stable, i.e. equivalent elements of either container preserve their relative position. In the special case&x==this, no operation is performed.
Postconditions: Elements in the index and remaining elements inxare sorted according tocomp. Validity of iterators to the index and of non-erased elements ofxreferences is preserved.
Complexity: If&x==this, constant; otherwiseO(n + x.size()*I(n+x.size()) + x.size()*D(x.size())).
Exception safety: If&x==this,nothrow; otherwise, basic.
void sort();
Requires:std::less<value_type>is aStrict Weak Orderingovervalue_type.
Effects: Sorts the index according tostd::less<value_type>. The sorting is stable, i.e. equivalent elements preserve their relative position.
Postconditions: Validity of iterators and references is preserved.
Complexity:O(n*log(n)).
Exception safety:nothrowifstd::less<value_type>does not throw; otherwise, basic.
template <typename Compare> void sort(Compare comp);
Requires:Compareis aStrict Weak Orderingovervalue_type.
Effects: Sorts the index according tocomp. The sorting is stable, i.e. equivalent elements preserve their relative position.
Postconditions: Validity of iterators and references is preserved.
Complexity:O(n*log(n)).
Exception safety:nothrowifcompdoes not throw; otherwise, basic.
void reverse();
Effects: Reverses the order of the elements in the index.
Postconditions: Validity of iterators and references is preserved.
Complexity:O(n).
Exception safety:nothrow.
These operations, without counterpart in std::list
(although splice provides partially overlapping
functionality), perform individual and global repositioning of elements
inside the index.
void relocate(iterator position,iterator i);
Requires:positionis a valid iterator of the index.iis a valid dereferenceable iterator of the index.
Effects: Inserts the element pointed to byibeforeposition. Ifposition==i, no operation is performed.
Postconditions: No iterator or reference is invalidated.
Complexity: Constant.
Exception safety:nothrow.
void relocate(iterator position,iterator first,iterator last);
Requires:positionis a valid iterator of the index.firstandlastare valid iterators of the index.lastis reachable fromfirst.positionis not in the range [first,last).
Effects: The range of elements [first,last) is repositioned just beforeposition.
Postconditions: No iterator or reference is invalidated.
Complexity: Constant.
Exception safety:nothrow.
template<typename InputIterator> void rearrange(InputIterator first);
Requires: The range [first,std::advance(first,n)), wherenis the size of the index, is a free view of the index.
Effects: The elements are rearranged so as to match the order of the previously described view.
Postconditions: No iterator or reference is invalidated.
Complexity:O(n).
Exception safety: Basic.
Indices cannot be serialized on their own, but only as part of the
multi_index_container into which they are embedded. In describing
the additional preconditions and guarantees associated to sequenced indices
with respect to serialization of their embedding containers, we
use the concepts defined in the multi_index_container
serialization section.
multi_index_container m to an
output archive (XML archive) ar.
Requires: No additional requirements to those imposed by the container.Operation: loading of a
multi_index_container m' from an
input archive (XML archive) ar.
Requires: No additional requirements to those imposed by the container.Operation: saving of an
Postconditions: On succesful loading, each of the elements of [begin(),end()) is a restored copy of the corresponding element in [m.get<i>().begin(),m.get<i>().end()), whereiis the position of the sequenced index in the container.
iterator or const_iterator
it to an output archive (XML archive) ar.
Requires:Operation: loading of anitis a valid iterator of the index. The associatedmulti_index_containerhas been previously saved.
iterator or const_iterator
it' from an input archive (XML archive) ar.
Postconditions: On succesful loading, ifitwas dereferenceable then*it'is the restored copy of*it, otherwiseit'==end().
Note: It is allowed thatitbe aconst_iteratorand the restoredit'aniterator, or viceversa.
Revised February 6th 2006
© Copyright 2003-2006 Joaquín M López Muñoz. Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)