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added Interoperable Iterators

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[SVN r21698]
This commit is contained in:
Jeremy Siek
2004-01-13 19:21:18 +00:00
parent 0f8aa07e5c
commit 80f6a13e79
3 changed files with 271 additions and 35 deletions
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71
doc/iter-issue-list.rst
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@ -1049,49 +1049,49 @@ c++std-lib-12641:
``result_of<UnaryFunction(iterator_traits<Iterator>::reference)>::type``. The
``value_type`` is ``remove_cv<remove_reference<reference> >::type``.
These are the defaults, right? If the user supplies their own types that's
what gets passed to iterator_adaptor. And again, the specification should
be in terms of the specialization of iterator_adaptor, and not in terms of
the result:
These are the defaults, right? If the user supplies their own types that's
what gets passed to iterator_adaptor. And again, the specification should
be in terms of the specialization of iterator_adaptor, and not in terms of
the result:
Reference argument to iterator_adaptor::
Reference argument to iterator_adaptor::
if (Reference != use_default)
if (Reference != use_default)
Reference
else
else
result_of<UnaryFunction(iterator_traits<Iterator>::reference)>::type
Value argument to iterator_adaptor::
Value argument to iterator_adaptor::
if (Value != use_default)
if (Value != use_default)
Value
else if (Reference != use_default)
else if (Reference != use_default)
remove_reference<reference>::type
else
else
remove_reference<result_of<UnaryFunction(iterator_traits<Iterator>::reference)>::type>::type
There's probably a better way to specify that last alternative, but I've
been at this too long, and it's all turning into a maze of twisty passages,
all alike.
There's probably a better way to specify that last alternative, but I've
been at this too long, and it's all turning into a maze of twisty passages,
all alike.
:Proposed resolution:
Replace:
The reference type of transform_iterator is
``result_of<UnaryFunction(iterator_traits<Iterator>::reference)>::type``. The
``value_type`` is ``remove_cv<remove_reference<reference> >::type``.
The reference type of transform_iterator is
``result_of<UnaryFunction(iterator_traits<Iterator>::reference)>::type``. The
``value_type`` is ``remove_cv<remove_reference<reference> >::type``.
with:
If ``Reference`` is ``use_default`` then the ``reference`` member of
``transform_iterator`` is
``result_of<UnaryFunction(iterator_traits<Iterator>::reference)>::type``.
Otherwise, ``reference`` is ``Reference``.
If ``Reference`` is ``use_default`` then the ``reference`` member of
``transform_iterator`` is
``result_of<UnaryFunction(iterator_traits<Iterator>::reference)>::type``.
Otherwise, ``reference`` is ``Reference``.
If ``Value`` is ``use_default`` then the ``value_type`` member is
``remove_cv<remove_reference<reference> >::type``. Otherwise,
``value_type`` is ``Value``.
If ``Value`` is ``use_default`` then the ``value_type`` member is
``remove_cv<remove_reference<reference> >::type``. Otherwise,
``value_type`` is ``Value``.
filter_iterator details unspecified
@ -1112,11 +1112,26 @@ The paper says::
/* see details */ >
That comment covers the Access, Traversal, Reference, and Difference
arguments. The only specification for any of these in the details is::
arguments. The only specification for any of these in the details is:
The access category of the filter_iterator will be the same as
the access category of Iterator.
The access category of the filter_iterator will be the same as
the access category of Iterator.
Needs more.
:Proposed resolution: **Needs work** (Jeremy)
:Proposed resolution:
Add to the synopsis::
typedef iterator_traits<Iterator>::value_type value_type;
typedef iterator_traits<Iterator>::reference reference;
typedef iterator_traits<Iterator>::pointer pointer;
typedef iterator_traits<Iterator>::difference_type difference_type;
typedef /* see below */ iterator_category;
and add just after the synopsis:
If ``Iterator`` models Readable Lvalue Iterator and Forward Traversal
Iterator then ``iterator_category`` is convertible to
``std::forward_iterator_tag``. Otherwise ``iterator_category`` is
convertible to ``std::input_iterator_tag``.