list_of Reference

namespace boost {
namespace bimap {


template< class KeyType >
struct list_of;

struct list_of_relation;


} // namespace bimap
} // namespace boost

list_of Views

Complexity signature
Instantiation types
Constructors, copy and assignment
Capacity operations
Modifiers
List operations
Rearrange operations
Serialization

A list_of set view is a std::list signature compatible interface to the underlying heap of elements contained in a bimap.

If you look the bimap by a side, you will use a map view and if you looked it as a whole you will be using a set view.

Elements in a list_of view are by default sorted according to their order of insertion: this means that new elements inserted through a different view of the bimap are appended to the end of the list_of view. Additionally, the view 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:

list_of views are not Assignable (like any other view.)
Unlike as in std::list, insertions into a list_of view may fail due to clashings with other views. This alters the semantics of the operations provided with respect to their analogues in std::list.
Elements in a list_of view are not mutable, and can only be changed by means of replace and modify member functions.

Having these restrictions into account, list_of views are models of 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 bimap {
namespace views {

template< -implementation defined parameter list- >
class -implementation defined view name-
{
    public:

    // types

    typedef -unspecified- value_type;
    typedef -unspecified- allocator_type;
    typedef -unspecified- reference;
    typedef -unspecified- const_reference;
    typedef -unspecified- iterator;
    typedef -unspecified- const_iterator;
    typedef -unspecified- size_type;
    typedef -unspecified- difference_type;
    typedef -unspecified- pointer;
    typedef -unspecified- const_pointer;
    typedef -unspecified- reverse_iterator;
    typedef -unspecified- const_reverse_iterator;

    // construct/copy/destroy

    this_type & operator=(const this_type & 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 clear();

    // list operations

    void splice(iterator position, this_type & x);
    void splice(iterator position, this_type & x, iterator i);
    void splice(
        iterator position, this_type & 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(this_type & x);
    template <typename Compare> void merge(this_type & 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);
}

// view comparison

bool operator==(const this_type & v1, const this_type & v2 );
bool operator< (const this_type & v1, const this_type & v2 );
bool operator!=(const this_type & v1, const this_type & v2 );
bool operator> (const this_type & v1, const this_type & v2 );
bool operator>=(const this_type & v1, const this_type & v2 );
bool operator<=(const this_type & v1, const this_type & v2 );

} // namespace views
} // namespace bimap
} // namespace boost

In the case of a bimap< list_of<Left>, ... >

In the set view:

typedef signature-compatible with relation< Left, ... > key_type;
typedef signature-compatible with relation< Left, ... > value_type;

In the left map view:

typedef  Left  key_type;
typedef  ...   data_type;

typedef signature-compatible with std::pair< Left, ... > value_type;

In the right map view:

typedef  ...  key_type;
typedef  Left data_type;

typedef signature-compatible with std::pair< ... , Left > value_type;

Complexity signature

Here and in the descriptions of operations of list_of views, we adopt the scheme outlined in the complexity signature section. The complexity signature of a list_of view is:

copying: c(n) = n * log(n),
insertion: i(n) = 1 (constant),
hinted insertion: h(n) = 1 (constant),
deletion: d(n) = 1 (constant),
replacement: r(n) = 1 (constant),
modifying: m(n) = 1 (constant).

Instantiation types

list_of views are instantiated internally to bimap and specified by means of the set type specifiers and the bimap itself. Instantiations are dependent on the following types:

Value from list_of,
Allocator from bimap,

Constructors, copy and assignment

As explained in the view concepts section, views do not have public constructors or destructors. Assignment, on the other hand, is provided.

this_type & operator=(const this_type & x);

Effects: a = b;
where a and b are the bimap objects to which *this and x belong, respectively.
Returns: *this.

template <class InputIterator>
void assign(InputIterator first, InputIterator last);

Requires: InputIterator is a model of Input Iterator over elements of type value_type or a type convertible to value_type. first and last are not iterators into any views of the bimap to which this view belongs. last is reachable from first.
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);

Capacity operations

void resize(size_type n,const value_type& x=value_type());

Effects:
if( n > size() ) insert(end(), n - size(), x);
else if( n < size() ){
iterator it = begin();
std::advance(it, n);
erase(it, end());
} Note: If an expansion is requested, the size of the view is not guaranteed to be n after this operation (other views may ban insertions.)

Modifiers

std::pair<iterator,bool> push_front(const value_type& x);

Effects: Inserts x at the beginning of the sequence if no other views of the bimap bans the insertion.
Returns: The return value is a pair p. p.second is true if and only if insertion took place. On successful insertion, p.first points to the element inserted; otherwise, p.first points 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: Inserts x at the end of the sequence if no other views of the bimap bans the insertion.
Returns: The return value is a pair p. p.second is true if and only if insertion took place. On successful insertion, p.first points to the element inserted; otherwise, p.first points 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: position is a valid iterator of the view.
Effects: Inserts x before position if insertion is allowed by all other views of the bimap.
Returns: The return value is a pair p. p.second is true if and only if insertion took place. On successful insertion, p.first points to the element inserted; otherwise, p.first points 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: position is a valid iterator of the view. Effects: for(size_type i = 0; i < n; ++i) insert(position, x);

template<typename InputIterator>
void insert(iterator position,InputIterator first,InputIterator last);

Requires: position is a valid iterator of the view. InputIterator is a model of Input Iterator over elements of type value_type. first and last are not iterators into any view of the bimap to which this view belongs. last is reachable from first.
Effects: while(first != last) insert(position, *first++);
Complexity: O(m*I(n+m)), where m is the number of elements in [first,last).
Exception safety: Basic.

iterator erase(iterator position);

Requires: position is a valid dereferenceable iterator of the view.
Effects: Deletes the element pointed to by position.
Returns: An iterator pointing to the element immediately following the one that was deleted, or end() 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 view.
Effects: Deletes the elements in [first,last).
Returns: last.
Complexity: O(m*D(n)), where m is the number of elements in [first,last).
Exception safety: nothrow.

bool replace(iterator position,const value_type& x);

Requires: position is a valid dereferenceable iterator of the view.
Effects: Assigns the value x to the element pointed to by position into the bimap to which the view belongs if replacing is allowed by all other views of the bimap.
Postconditions: Validity of position is preserved in all cases.
Returns: true if the replacement took place, false otherwise.
Complexity: O(R(n)).
Exception safety: Strong. If an exception is thrown by some user-provided operation the bimap to which the view belongs remains in its original state.

template<typename Modifier> bool modify(iterator position,Modifier mod);

Requires: Modifier is a model of Binary Function accepting arguments of type:
Map View: first_type& and second_type&
Set View: left_type& and right_type&
position is a valid dereferenceable iterator of the view.
Effects:
Map View: Calls mod(e.first,e.second)
Set View: Calls mod(e.left,e.right)
where e is the element pointed to by position and rearranges *position into all the views of the bimap. Rearrangement on list_of views does not change the position of the element with respect to the view; rearrangement on other views may or might not suceed. If the rearrangement fails, the element is erased.
Postconditions: Validity of position is preserved if the operation succeeds.
Returns: true if the operation succeeded, false otherwise.
Complexity: O(M(n)).
Exception safety: Basic. If an exception is thrown by some user-provided operation (except possibly mod), then the element pointed to by position is erased.

List operations

list_of views 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 views. Similarly, the complexity of the operations may depend on the other views belonging to the same bimap.

void splice(iterator position, this_type & x);

Requires: position is a valid iterator of the view. &x!=this.
Effects: Inserts the contents of x before position, in the same order as they were in x. Those elements successfully inserted are erased from x.
Complexity: O(x.size()*I(n+x.size()) + x.size()*D(x.size())).
Exception safety: Basic.

void splice(iterator position, this_type & x,iterator i);

Requires: position is a valid iterator of the view. i is a valid dereferenceable iterator x.
Effects: Inserts the element pointed to by i before position: if insertion is successful, the element is erased from x. In the special case &x==this, no copy or deletion is performed, and the operation is always successful. If position==i, no operation is performed.
Postconditions: If &x==this, no iterator or reference is invalidated.
Complexity: If &x==this, constant; otherwise O(I(n) + D(n)).
Exception safety: If &x==this, nothrow; otherwise, strong.

void splice(iterator position, this_type & x, iterator first, iterator last);

Requires: position is a valid iterator of the view. first and last are valid iterators of x. last is reachable from first. position is not in the range [first,last).
Effects: For each element in the range [first,last), insertion is tried before position; if the operation is successful, the element is erased from x. In the special case &x==this, no copy or deletion is performed, and insertions are always successful.
Postconditions: If &x==this, no iterator or reference is invalidated.
Complexity: If &x==this, constant; otherwise O(m*I(n+m) + m*D(x.size())) where m is 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 view which compare equal to value.
Complexity: O(n + m*D(n)), where m is the number of elements erased.
Exception safety: Basic.

template<typename Predicate> void remove_if(Predicate pred);

Effects: Erases all elements x of the view for which pred(x) holds.
Complexity: O(n + m*D(n)), where m is 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 iterator i in the range [first+1,last) for which *i==*(i-1).
Complexity: O(n + m*D(n)), where m is 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 iterator i in the range [first+1,last) for which binary_pred(*i,*(i-1)) holds.
Complexity: O(n + m*D(n)), where m is the number of elements erased.
Exception safety: Basic.

void merge(this_type & x);

Requires: std::less<value_type> is a Strict Weak Ordering over value_type. Both the view and x are sorted according to std::less<value_type>.
Effects: Attempts to insert every element of x into the corresponding position of the view (according to the order). Elements successfully inserted are erased from x. 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 view and remaining elements in x are sorted. Validity of iterators to the view and of non-erased elements of x references is preserved.
Complexity: If &x==this, constant; otherwise O(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(this_type & x,Compare comp);

Requires: Compare is a Strict Weak Ordering over value_type. Both the view and x are sorted according to comp.
Effects: Attempts to insert every element of x into the corresponding position of the view (according to comp). Elements successfully inserted are erased from x. 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 view and remaining elements in x are sorted according to comp. Validity of iterators to the view and of non-erased elements of x references is preserved.
Complexity: If &x==this, constant; otherwise O(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 a Strict Weak Ordering over value_type.
Effects: Sorts the view according to std::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: nothrow if std::less<value_type> does not throw; otherwise, basic.

template <typename Compare> void sort(Compare comp);

Requires: Compare is a Strict Weak Ordering over value_type.
Effects: Sorts the view according to comp. 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: nothrow if comp does not throw; otherwise, basic.

void reverse();

Effects: Reverses the order of the elements in the view.
Postconditions: Validity of iterators and references is preserved.
Complexity: O(n).
Exception safety: nothrow.

Rearrange operations

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: position is a valid iterator of the view. i is a valid dereferenceable iterator of the view.
Effects: Inserts the element pointed to by i before position. If position==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: position is a valid iterator of the view. first and last are valid iterators of the view. last is reachable from first. position is not in the range [first,last).
Effects: The range of elements [first,last) is repositioned just before position.
Postconditions: No iterator or reference is invalidated.
Complexity: Constant.
Exception safety: nothrow.

Serialization

Views cannot be serialized on their own, but only as part of the bimap into which they are embedded. In describing the additional preconditions and guarantees associated to list_of views with respect to serialization of their embedding containers, we use the concepts defined in the bimap serialization section.

Operation: saving of a bimap b to an output archive (XML archive) ar.

Requires: No additional requirements to those imposed by the container.

Operation: loading of a bimap b' from an input archive (XML archive) ar.

Requires: No additional requirements to those imposed by the container.
Postconditions: On successful 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()), where i is the position of the list_of view in the container.

Operation: saving of an iterator or const_iterator it to an output archive (XML archive) ar.

Requires: it is a valid iterator of the view. The associated bimap has been previously saved.

Operation: loading of an iterator or const_iterator it' from an input archive (XML archive) ar.

Postconditions: On successful loading, if it was dereferenceable then *it' is the restored copy of *it, otherwise it' == end().
Note: It is allowed that it be a const_iterator and the restored it' an iterator, or viceversa.