mirror of
https://github.com/boostorg/iterator.git
synced 2025-05-11 13:33:56 +00:00
178 lines
4.6 KiB
ReStructuredText
178 lines
4.6 KiB
ReStructuredText
.. parsed-literal::
|
|
|
|
bool
|
|
template <
|
|
class Derived
|
|
, class Base
|
|
, class Value = use_default
|
|
, unsigned Access = use_default_access
|
|
, class Traversal = use_default
|
|
, class Reference = use_default
|
|
, class Difference = use_default
|
|
>
|
|
class iterator_adaptor
|
|
: public iterator_facade<Derived, /* see details__ ...\*/>
|
|
{
|
|
friend class iterator_core_access;
|
|
public:
|
|
iterator_adaptor();
|
|
explicit iterator_adaptor(Base iter);
|
|
Base base() const;
|
|
protected:
|
|
Base const& base_reference() const;
|
|
Base& base_reference();
|
|
private: // Core iterator interface for iterator_facade.
|
|
typename iterator_adaptor::reference dereference() const;
|
|
|
|
template <
|
|
class OtherDerived, class OtherIterator, class V, class C, class R, class D
|
|
>
|
|
bool equal(iterator_adaptor<OtherDerived, OtherIterator, V, C, R, D> const& x) const;
|
|
|
|
void advance(typename iterator_adaptor::difference_type n);
|
|
void increment();
|
|
void decrement();
|
|
|
|
template <
|
|
class OtherDerived, class OtherIterator, class V, class C, class R, class D
|
|
>
|
|
typename iterator_adaptor::difference_type distance_to(
|
|
iterator_adaptor<OtherDerived, OtherIterator, V, C, R, D> const& y) const;
|
|
|
|
private:
|
|
Base m_iterator;
|
|
};
|
|
|
|
__ :
|
|
|
|
``iterator_adaptor`` requirements
|
|
---------------------------------
|
|
|
|
The ``Derived`` template parameter must be a derived class of
|
|
``iterator_adaptor``. The ``Base`` type must implement the
|
|
expressions involving ``m_iterator`` in the specifications of those
|
|
private member functions of ``iterator_adaptor`` that are not
|
|
redefined by the ``Derived`` class and that are needed to model the
|
|
concept corresponding to
|
|
``iterator_traits<Derived>::iterator_category`` according to the
|
|
requirements of ``iterator_facade``. The rest of the template
|
|
parameters specify the types for the member typedefs in
|
|
``iterator_facade``. The following pseudo-code specifies the
|
|
traits types for ``iterator_adaptor``.
|
|
|
|
::
|
|
|
|
if (Value != use_default)
|
|
value_type = remove_cv<Value>::type;
|
|
else
|
|
value_type = iterator_traits<Base>::value_type;
|
|
|
|
|
|
if (Traversal != use_default)
|
|
traversal_category = Traversal
|
|
else
|
|
traversal_category = traversal_category< Base >::type
|
|
|
|
iterator_category = iterator_tag<
|
|
access_category
|
|
, traversal_category
|
|
>
|
|
|
|
if (Access != use_default)
|
|
{
|
|
access_category = Access
|
|
}
|
|
else
|
|
{
|
|
access_category
|
|
= access_category< Base >::value
|
|
|
|
if (is_const<Value>)
|
|
access_category &= ~writable_iterator;
|
|
}
|
|
|
|
iterator_category = iterator_tag<
|
|
access_category
|
|
, traversal_category
|
|
>
|
|
|
|
if (Reference != use_default)
|
|
reference = Reference
|
|
else if (Value != use_default)
|
|
reference = Value&
|
|
else
|
|
reference = iterator_traits<Base>::reference
|
|
|
|
|
|
``iterator_adaptor`` public operations
|
|
--------------------------------------
|
|
|
|
``iterator_adaptor();``
|
|
|
|
:Requires: The ``Base`` type must be Default Constructible.
|
|
:Returns: An instance of ``iterator_adaptor`` with
|
|
``m_iterator`` default constructed.
|
|
|
|
|
|
``explicit iterator_adaptor(Base iter);``
|
|
|
|
:Returns: An instance of ``iterator_adaptor`` with
|
|
``m_iterator`` copy constructed from ``iter``.
|
|
|
|
``Base base() const;``
|
|
|
|
:Returns: ``m_iterator``
|
|
|
|
|
|
``iterator_adaptor`` protected member functions
|
|
-----------------------------------------------
|
|
|
|
``Base const& base_reference() const;``
|
|
|
|
:Returns: A const reference to ``m_iterator``.
|
|
|
|
|
|
``Base& base_reference();``
|
|
|
|
:Returns: A non-const reference to ``m_iterator``.
|
|
|
|
|
|
``iterator_adaptor`` private member functions
|
|
---------------------------------------------
|
|
|
|
``typename iterator_adaptor::reference dereference() const;``
|
|
|
|
:Returns: ``*m_iterator``
|
|
|
|
::
|
|
|
|
template <
|
|
class OtherDerived, class OtherIterator, class V, class C, class R, class D
|
|
>
|
|
bool equal(iterator_adaptor<OtherDerived, OtherIterator, V, C, R, D> const& x) const;
|
|
|
|
:Returns: ``m_iterator == x.base()``
|
|
|
|
|
|
``void advance(typename iterator_adaptor::difference_type n);``
|
|
|
|
:Effects: ``m_iterator += n;``
|
|
|
|
``void increment();``
|
|
|
|
:Effects: ``++m_iterator;``
|
|
|
|
``void decrement();``
|
|
|
|
:Effects: ``--m_iterator;``
|
|
|
|
::
|
|
|
|
template <
|
|
class OtherDerived, class OtherIterator, class V, class C, class R, class D
|
|
>
|
|
typename iterator_adaptor::difference_type distance_to(
|
|
iterator_adaptor<OtherDerived, OtherIterator, V, C, R, D> const& y) const;
|
|
|
|
:Returns: ``y.base() - m_iterator``
|