iterator/doc/transform_iterator_ref.rst
2003-08-05 19:42:37 +00:00

96 lines
2.9 KiB
ReStructuredText

::
template <class AdaptableUnaryFunction,
class Iterator,
class Reference = use_default,
class Value = use_default>
class transform_iterator
: public iterator_adaptor</* see discussion */>
{
friend class iterator_core_access;
public:
transform_iterator();
transform_iterator(Iterator const& x, AdaptableUnaryFunction f);
template<class OtherIterator, class R2, class V2>
transform_iterator(
transform_iterator<AdaptableUnaryFunction, OtherIterator, R2, V2> const& t
, typename enable_if_convertible<OtherIterator, Iterator>::type* = 0 // exposition
);
AdaptableUnaryFunction functor() const;
private:
typename transform_iterator::value_type dereference() const;
AdaptableUnaryFunction m_f;
};
``transform_iterator`` requirements
...................................
The type ``AdaptableUnaryFunction`` must be Assignable, Copy
Constructible, and the expression ``f(x)`` must be valid where ``f``
is an object of type ``AdaptableUnaryFunction``, ``x`` is an object of
type ``AdaptableUnaryFunction::argument_type``, and where the type of
``f(x)`` must be ``AdaptableUnaryFunction::result_type``.
The type ``Iterator`` must at least model Readable Iterator. The
resulting ``transform_iterator`` models the most refined of the
following options that is also modeled by ``Iterator``.
* Writable Lvalue Iterator if the ``result_type`` of the
``AdaptableUnaryFunction`` is a non-const reference.
* Readable Lvalue Iterator if the ``result_type`` is a const
reference.
* Readable Iterator otherwise.
The ``transform_iterator`` models the most refined standard traversal
concept that is modeled by ``Iterator``.
The ``value_type`` of ``transform_iterator`` is
``remove_reference<result_type>::type``. The ``reference`` type is
``result_type``.
``transform_iterator`` public operations
........................................
``transform_iterator();``
:Returns: An instance of ``transform_iterator`` with ``m_f``
and ``m_iterator`` default constructed.
``transform_iterator(Iterator const& x, AdaptableUnaryFunction f);``
:Returns: An instance of ``transform_iterator`` with ``m_f``
initialized to ``f`` and ``m_iterator`` initialized to ``x``.
::
template<class OtherIterator, class R2, class V2>
transform_iterator(
transform_iterator<AdaptableUnaryFunction, OtherIterator, R2, V2> const& t
, typename enable_if_convertible<OtherIterator, Iterator>::type* = 0 // exposition
);
:Returns: An instance of ``transform_iterator`` that is a copy of ``t``.
:Requires: ``OtherIterator`` is implicitly convertible to ``Iterator``.
``AdaptableUnaryFunction functor() const;``
:Returns: ``m_f``
``transform_iterator`` private operations
.........................................
``typename transform_iterator::value_type dereference() const;``
:Returns: ``m_f(transform_iterator::dereference());``