set_of.qbk

Boost provides free peer-reviewed portable C++ source libraries. We emphasize libraries that work

operation (except possibly mod), then the element pointed to by position is erased.

]

[endsect]

[section Set operations]

`[multi]set_of` views provide the full lookup functionality required by
__SGI_SORTED_ASSOCIATIVE_CONTAINER__ and __SGI_UNIQUE_ASSOCIATIVE_CONTAINER__,
namely `find`, `count`, `lower_bound`, `upper_bound` and `equal_range`.
Additionally, these member functions are templatized to allow for non-standard
arguments, so extending the types of search operations allowed.

[/
The kinds of arguments permissible when invoking the lookup member functions
are defined by the following concept.

Consider a __SGI_STRICT_WEAK_ORDERING__ `Compare` over values of type `Key`. A pair of
types `(CompatibleKey, CompatibleCompare)` is said to be a ['compatible extension]
of Compare if

* `CompatibleCompare` is a __SGI_BINARY_PREDICATE__ over `(Key, CompatibleKey)`,
* `CompatibleCompare` is a __SGI_BINARY_PREDICATE__ over `(CompatibleKey, Key)`,
* if `c_comp(ck,k1)` then `!c_comp(k1,ck)`,
* if `!c_comp(ck,k1)` and `!comp(k1,k2)` then `!c_comp(ck,k2)`,
* if `!c_comp(k1,ck)` and `!comp(k2,k1)` then `!c_comp(k2,ck)`,

for every `c_comp` of type `CompatibleCompare`, `comp` of type `Compare`, `ck` of type
`CompatibleKey` and `k1`, `k2` of type `Key`.
]
A type `CompatibleKey` is said to be a ['compatible key] of `Compare`
if `(CompatibleKey, Compare)` is a compatible extension of `Compare`. This implies
that `Compare`, as well as being a strict weak ordering, accepts arguments of type
`CompatibleKey`, which usually means it has several overloads of `operator()`.

[/
In the context of a compatible extension or a compatible key, the expressions
"equivalent", "less than" and "greater than" take on their obvious interpretations.
]

[#reference_set_of_find_key]

    template< class CompatibleKey >
    iterator find(const CompatibleKey & x);

    template< class CompatibleKey >
    const_iterator find(const CompatibleKey & x) const;

* [*Requires: ] `CompatibleKey` is a compatible key of `key_compare`.
* [*Effects:] Returns a pointer to an element whose key is equivalent to `x`, or
`end()` if such an element does not exist.
* [*Complexity:] O(log(n)).

[/
    template< class CompatibleKey, class CompatibleCompare >
    iterator find(const CompatibleKey & x,
                  const CompatibleCompare & comp);

    template< class CompatibleKey, class CompatibleCompare >
    const_iterator find(const CompatibleKey & x,
                        const CompatibleCompare & comp) const;

* [*Requires: ] `(CompatibleKey, CompatibleCompare)` is a compatible extension of
`key_compare.`
* [*Effects:] Returns a pointer to an element whose key is
equivalent to `x`, or `end()` if such an element does not exist.
* [*Complexity:] O(log(n)).
]

[#reference_set_of_count_key]

    template< class CompatibleKey >
    size_type count(const key_type & x) const;

* [*Requires: ] `CompatibleKey` is a compatible key of `key_compare`.
* [*Effects:] Returns the number of elements with key equivalent to `x`.
* [*Complexity:] O(log(n) + count(x)).

[/
    template< class CompatibleKey, class CompatibleCompare >
    size_type count(const CompatibleKey & x,
                    const CompatibleCompare & comp) const;

* [*Requires: ] `(CompatibleKey, CompatibleCompare)` is a compatible extension of
`key_compare.`
* [*Effects:] Returns the number of elements with key equivalent to `x`.
* [*Complexity:] O(log(n) + count(x)).
]

[#reference_set_of_lower_bound_key]

    template< class CompatibleKey >
    iterator lower_bound(const key_type & x);

    template< class CompatibleKey >
    const_iterator lower_bound(const key_type & x) const;

* [*Requires: ] `CompatibleKey` is a compatible key of `key_compare`.
* [*Effects:] Returns an iterator pointing to the first element with key not
less than `x`, or `end()` if such an element does not exist.
* [*Complexity:] O(log(n)).


[#reference_set_of_upper_bound_key]

    template< class CompatibleKey >
    iterator upper_bound(const key_type & x);

    template< class CompatibleKey >
    const_iterator upper_bound(const key_type & x) const;

* [*Requires: ] `CompatibleKey` is a compatible key of `key_compare`.
* [*Effects:] Returns an iterator pointing to the first element with key greater
than `x`, or `end()` if such an element does not exist.
* [*Complexity:] O(log(n)).


[#reference_set_of_equal_range_key]

    template< class CompatibleKey >
    std::pair<iterator,iterator>
        equal_range(const key_type & x);

    template< class CompatibleKey >
    std::pair<const_iterator,const_iterator> 
        equal_range(const key_type & x) const;

* [*Requires: ] `CompatibleKey` is a compatible key of `key_compare`.
* [*Effects:] Equivalent to `make_pair(lower_bound(x),upper_bound(x))`.
* [*Complexity:] O(log(n)).



[endsect]

[section Range operations]

The member function range is not defined for sorted associative
containers, but `[multi]set_of` map views provide it as a convenient utility.
A range or interval is defined by two conditions for the lower and upper
bounds, which are modelled after the following concepts.

Consider a __SGI_STRICT_WEAK_ORDERING__ `Compare` over values of type Key.
A type `LowerBounder` is said to be a lower bounder of `Compare` if

* `LowerBounder` is a `Predicate` over `Key`,
* if `lower(k1)` and `!comp(k2,k1)` then `lower(k2)`,

for every `lower` of type `LowerBounder`, `comp` of type `Compare`, and `k1`, `k2`
of type `Key`.
Similarly, an upper bounder is a type `UpperBounder` such that

* `UpperBounder` is a `Predicate` over `Key`,
* if `upper(k1)` and `!comp(k1,k2)` then `upper(k2)`,

for every `upper` of type `UpperBounder`, `comp` of type `Compare`, and `k1`, `k2`
of type `Key`.

[#reference_set_of_range_lower_upper]

    template< class LowerBounder, class UpperBounder>
    std::pair<const_iterator,const_iterator> range(
        LowerBounder lower, UpperBounder upper) const;

* [*Requires: ] `LowerBounder` and `UpperBounder` are a lower and upper bounder of
`key_compare`, respectively.
* [*Effects:] Returns a pair of iterators pointing to
the beginning and one past the end of the subsequence of elements satisfying
lower and upper simultaneously. If no such elements exist, the iterators both
point to the first element satisfying lower, or else are equal to `end()` if this
latter element does not exist.
* [*Complexity:] O(log(n)).
* [*Variants:] In place of lower or upper (or both), the singular value
`boost::bimap::unbounded` can be provided. This acts as a predicate which
all values of type `key_type` satisfy.
* [*Note:] Only provided for map views.

[endsect]

[section at(), info_at() and operator\[\] - set_of only]

[#reference_set_of_at_key_const]

    template< class CompatibleKey >
    const data_type & at(const CompatibleKey & k) const;

* [*Requires: ] `CompatibleKey` is a compatible key of `key_compare`.
* [*Effects:] Returns the `data_type` reference that is associated with `k`, or
throws `std::out_of_range` if such key does not exist.
* [*Complexity:] O(log(n)).
* [*Note:] Only provided when `set_of` is used.

The symmetry of bimap imposes some constraints on `operator[]` and the 
non constant version of at() that are not found in `std::maps`.
Tey are only provided if the other collection type is mutable
(`list_of`, `vector_of` and `unconstrained_set_of`).

[#reference_set_of_operator_bracket_key]

    template< class CompatibleKey >
    data_type & operator[](const CompatibleKey & k);

* [*Requires: ] `CompatibleKey` is a compatible key of `key_compare`.
* [*Effects: ] `return insert(value_type(k,data_type()))->second;`
* [*Complexity:] O(log(n)).
* [*Note:] Only provided when `set_of` is used and the other collection
type is mutable.

[#reference_set_of_at_key]

    template< class CompatibleKey >
    data_type & at(const CompatibleKey & k);

* [*Requires: ] `CompatibleKey` is a compatible key of `key_compare`.
* [*Effects: ] Returns the `data_type` reference that is associated with `k`, or
throws `std::out_of_range` if such key does not exist.
* [*Complexity:] O(log(n)).
* [*Note:] Only provided when `set_of` is used and the other collection
type is mutable.

[/
The symmetry of bimap imposes some constraints on `operator[]` that are
not found in `std::maps`. If other views are unique,
`bimap::duplicate_value` is thrown whenever an assignment is attempted to
a value that is already a key in these views. As for
`bimap::value_not_found`, this exception is thrown while trying to access
a non-existent key: this behaviour differs from that of `std::map`, which
automatically assigns a default value to non-existent keys referred to
by `operator[]`.

    const data_type & operator[](const typename key_type & k) const;

* [*Effects:] Returns the `data_type` reference that is associated with `k`, or
throws `bimap::value_not_found` if such an element does not exist.
* [*Complexity:] O(log(n)).


    ``['-unspecified data_type proxy-]`` operator[](const typename key_type & k);

* [*Effects:] Returns a proxy to a `data_type` associated with `k` and the
bimap. The proxy behaves as a reference to the `data_type` object. If this
proxy is read and `k` was not in the bimap, the bimap::value_not_found is
thrown. If it is written then `bimap::duplicate_value` is thrown if the
assignment is not allowed by one of the other views of the `bimap`.
* [link set_of_complexity_signature
[*Complexity:]] If the assignment operator of the proxy is not used, then
the order is O(log(n)). If it is used, the order is O(I(n)) if `k` was not
in the bimap and O(R(n)) if it existed in the bimap.
]


[#reference_set_of_info_at_key]

    template< class CompatibleKey >
    info_type & info_at(const CompatibleKey & k);

    template< class CompatibleKey >
    const info_type & info_at(const CompatibleKey & k) const;

* [*Requires: ] `CompatibleKey` is a compatible key of `key_compare`.
* [*Effects:] Returns the `info_type` reference that is associated with `k`, or
throws `std::out_of_range` if such key does not exist.
* [*Complexity:] O(log(n)).
* [*Note:] Only provided when `set_of` and `info_hook` are used


[endsect]

[section 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 `[multi]set_of` views with respect to serialization of their embedding containers,
we use the concepts defined in the `bimap` serialization section.

[blurb  [*Operation:] saving of a `bimap` m to an output archive (XML archive) ar.]

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


[blurb [*Operation:] loading of a `bimap` m' from an input archive (XML archive) ar.]

* [*Requires:] In addition to the general requirements, `value_comp()` must be
serialization-compatible with `m.get<i>().value_comp()`, where i is the position
of the ordered view in 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())`.



[blurb [*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.


[blurb [*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.


[endsect]
[endsect]

[endsect]