factored iterator adaptor stuff and a few other edits

[SVN r19465]
2025-07-23 09:27:15 +02:00 · 2003-08-05 18:19:55 +00:00
parent 19977c757f
commit 0f42b93c3b
9 changed files with 656 additions and 308 deletions
--- a/doc/iterator_adaptor_ref.rst
+++ b/doc/iterator_adaptor_ref.rst
@ -0,0 +1,176 @@
+.. parsed-literal::
+  
+  template <
+      class Derived
+    , class Base
+    , class Value      = use_default
+    , class Category   = 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 the chosen ``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 = iterator_traits<Base>::value_type;
+    else 
+        value_type = remove_cv<Value>::type;
+
+    if (Reference == use_default) {
+        if (Value == use_default)
+            reference = iterator_traits<Base>::reference;
+        else 
+            reference = Value&;
+    } else
+        reference = Reference;
+
+    if (Distance == use_default)
+        difference_type = iterator_traits<Base>::difference_type;
+    else
+        difference_type = Distance;
+
+    if (Category == use_default)
+        iterator_category = iterator_tag< 
+            access_category< 
+                iterator< iterator_traits<Base>::iterator_category,
+                          Value,
+                          Distance,
+                          Value*,
+                          Reference > >,
+            traversal_category<
+                iterator< iterator_traits<Base>::iterator_category,
+                          Value,
+                          Distance,
+                          Value*,
+                          Reference > >
+    else
+        iterator_category = Category;
+
+
+..  Replaced with new semantics --thw
+    if (Category == use_default)
+        iterator_category = iterator_traits<Base>::iterator_category;
+    else
+        iterator_category = Category;
+
+
+
+``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``