forked from boostorg/iterator
updates
[SVN r21735]
This commit is contained in:
Dave Abrahams
@ -62,8 +62,8 @@ to be members or non-members.
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or non-members.
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9.3 enable_if_interoperable needs standardese
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=============================================
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9.3 enable_if_interoperable needs standardese (Dave)
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====================================================
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:Submitter: Pete Becker
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:Status: New
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@ -195,7 +195,7 @@ which doesn't require iterators to be copy constructible or assignable).
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similar to 9.3, "Specialized Adaptors" has a note describing enable_if_convertible. This should
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be normative text.
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:Proposed resolution: **Needs work** (Dave) Change it to normative
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:Proposed resolution: Changed it to normative
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text. See the resolution of 9.4
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9.9 Reverse_iterator text is too informal
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@ -258,7 +258,7 @@ transform_iterator has a private member named 'm_f' which should be marked "expo
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:Proposed resolution: Mark the member m_f as exposition
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only. Note/DWA: I think this is NAD because the user can't
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detect it, though I'm happy to makr it exposition only.
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detect it, though I'm happy to mark it exposition only.
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9.13 Unclear description of counting iterator
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@ -534,8 +534,8 @@ awkward, but at the moment I don't see a better way of phrasing it.
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need to be able to unambigously cast the iterator_facade specialisation
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to Iter.
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9.22 return type of Iterator difference for iterator facade
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===========================================================
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9.22 return type of Iterator difference for iterator facade (Dave)
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==================================================================
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:Submitter: Pete Becker
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:Status: New
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@ -569,7 +569,7 @@ right?
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different but interoperable iterator types?
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9.23 Iterator_facade: minor wording Issue
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9.23 Iterator_facade: minor wording Issue
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=========================================
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:Submitter: Pete Becker
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@ -583,7 +583,8 @@ iterator_facade, the entry for c.equal(y) says:
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not implement either of these operations. It is used to implement
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them. Same thing in the description of c.distance_to(z).
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:Proposed resolution: **Needs work** (Dave) Reword.
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:Proposed resolution: remove "implements" descriptions from
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table. See resolution to 9.34
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9.24 Use of undefined name in iterator_facade table
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@ -598,7 +599,7 @@ below, X is the derived iterator type." Looks like the X:: qualifiers aren't rea
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X::reference can simply be reference, since that's defined by the iterator_facade specialization
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itself.
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:Proposed resolution: **Needs language** (Dave) Remove the use of X.
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:Proposed resolution: Removed the use of X.
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9.25 Iterator_facade: wrong return type
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@ -646,14 +647,7 @@ says:
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can assign a value_type object to it. Should that be ``*p = v``?
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But why the cast in reference(a[n] = v)?
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:Proposed resolution: **Needs work**
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(Dave)
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Change ``*this`` to ``*static_cast<Derived*>(this)``. Also reword
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the stuff about ``X::reference(a[n] = v)`` is equivalent to ``p =
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v``. Also make sure whatever's written accounts for ``v = a[n]``
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:Proposed resolution: Reworded.
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9.27 Iterator_facade: redundant clause
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======================================
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@ -681,11 +675,11 @@ it does not reach inside the base class for its semantics. So the default constr
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:Proposed resolution: Change the specification of the default constructor to
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``indirect_iterator();``
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``indirect_iterator();``
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:Requires: ``Iterator`` must be Default Constructible.
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:Returns: An instance of ``indirect_iterator`` with
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a default-constructed ``m_iterator``.
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:Requires: ``Iterator`` must be Default Constructible.
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:Returns: An instance of ``indirect_iterator`` with
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a default-constructed ``m_iterator``.
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:Rationale: Inheritance from iterator_adaptor has been removed, so we instead
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@ -746,7 +740,12 @@ in that order, i.e. Value precedes Reference in the template argument list, with
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transform_iterator, where Reference precedes Value. This seems like a possible source of
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confusion. Is there a reason why this order is preferable?
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:Proposed resolution: Change the argument order so that Value precedes reference.
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:Proposed resolution: NAD
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:Rationale: defaults for Value depend on Reference. A sensible
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Value can almost always be computed from Reference. The first
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parameter is UnaryFunction, so the argument order is already
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different from the other adapters.
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9.31 function_output_iterator overconstrained
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@ -766,16 +765,16 @@ and to increment such an object. It's only when you try to assign through a dere
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that f(x) has to work, and then only for the particular function object that the iterator holds and
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for the particular value that is being assigned.
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:Proposed resolution:
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Remove the part of the sentence after "and". Remove the use of
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``output_proxy`` and instead specify ``operator*`` in the following way.
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:Proposed resolution: Remove the part of the sentence
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after "and". Remove the use of ``output_proxy`` and instead
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specify ``operator*`` in the following way.
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``/* implementation defined */ operator*();``
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``/* implementation defined */ operator*();``
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:Returns: An object ``r`` of implementation defined type
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such that if ``f(t)`` is a valid expression for
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some object ``t`` then ``r = t`` is a valid expression.
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``r = t`` will have the same effect as ``f(t)``.
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:Returns: An object ``r`` of implementation defined type
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such that if ``f(t)`` is a valid expression for
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some object ``t`` then ``r = t`` is a valid expression.
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``r = t`` will have the same effect as ``f(t)``.
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9.32 Should output_proxy really be a named type?
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@ -788,8 +787,7 @@ This means someone can store an output_proxy object for later use, whatever that
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constrains output_proxy to hold a copy of the function object, rather than a pointer to the iterator
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object. Is all this mechanism really necessary?
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:Proposed resolution:
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See issue 9.31.
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:Proposed resolution: See issue 9.31.
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@ -820,8 +818,8 @@ c++std-lib-12333:
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this issue for Readable Iterator and Lvalue Iterator.
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9.34 iterator_facade free functions unspecified
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===============================================
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9.34 iterator_facade free functions unspecified (Dave)
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======================================================
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:Submitter: Pete Becker
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:Status: New
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@ -836,7 +834,7 @@ c++std-lib-12562:
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iterator_facade and an argument of type difference_type has no
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specification.
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:Proposed resolution: **Needs work** (Dave) Add the missing specifications.
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:Proposed resolution: **Needs work** Add the missing specifications.
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9.35 iterator_facade: too many equals?
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@ -876,6 +874,7 @@ c++std-lib-12636:
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The table that lists required functions for the derived type X passed to iterator_facade lists,
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among others:
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for a single pass iterator::
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c.equal(b)
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@ -898,12 +897,7 @@ c++std-lib-12636:
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z)". The template function distance takes two arguments of the same type, so distance(c, z) isn't
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valid if c and z are different types. Should it be distance(c, (X)z)?
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:Proposed resolution: **Needs work** (Dave)
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We need to define what "same position" means for iterators. This also
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needs to be part of the definition of an Interoperable Iterator
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concept.
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:Proposed resolution: Removed the 'b' versions, added the cast.
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====================================
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More Issues (not from Matt's list)
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@ -925,19 +919,16 @@ iterator_adaptor. That seems like overspecification, and we ought to
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look at specifying these things in terms of what the various templates
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provide rather than how they're implemented.
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:Proposed resolution: **Needs work** (Dave)
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:Proposed resolution:
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Remove the specfication of inheritance, and explicit specification of
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all the functionality that was inherited. In iterator_adaptor, that
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means adding a lot of function prototypes. In the other adaptors, that
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means making sure we state what concepts are modeled, in addition to
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specifying the semantics of some core operations. Also, the
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Interoperable Iterators concept is added to the new iterator concepts,
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and this concept is used in the specification of the iterator
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adaptors.
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Remove the specfication of inheritance, and explicit specification of
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all the functionality that was inherited from the specialized
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iterators.
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.. The specialized adaptors have been updated. iterator facade and
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adaptor still need to be updated. -JGS
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In iterator_adaptor, inheritance is retained, sorry NAD. Also,
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the Interoperable Iterators concept is added to the new iterator
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concepts, and this concept is used in the specification of the
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iterator adaptors.
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Problem with specification of a->m in Readable Iterator
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@ -958,12 +949,11 @@ readable requirements?
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Would it be better for the requirements to read ``static_cast<T>(*a).m``
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instead of ``(*a).m`` ?
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:Proposed resolution: Change the requirement to
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:Proposed resolution: NAD.
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:pre: ``static_cast<T const&>(*a).m`` is well-defined. If
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``static_cast<T&>(*a).m`` is well-defined, equivalent to
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``static_cast<T&>(*a).m``; otherwise, equivalent to
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``static_cast<T const&>(*a).m``.
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:Rationale: We think you're misreading "pre:".
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Also requiring proxy iterators to support ``->`` would make old
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iterators not conform to new iterator requirements.
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counting_iterator Traversal argument unspecified
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@ -1031,14 +1021,7 @@ c++std-lib-12640:
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to find a different way to say it. If it's the latter we need to
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say so.
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:Proposed resolution: **Needs work** (Jeremy)
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:Rationale:
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iterator_facade just does remove_const<Value>::type, so value_type is
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volatile if Value is.
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:Proposed resolution: Resolved **Needs Language**
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Problem with transform_iterator requirements
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@ -1078,23 +1061,22 @@ been at this too long, and it's all turning into a maze of twisty passages,
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all alike.
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:Proposed resolution:
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Replace:
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Replace:
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The reference type of transform_iterator is
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``result_of<UnaryFunction(iterator_traits<Iterator>::reference)>::type``. The
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``value_type`` is ``remove_cv<remove_reference<reference> >::type``.
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The reference type of transform_iterator is
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``result_of<UnaryFunction(iterator_traits<Iterator>::reference)>::type``. The
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``value_type`` is ``remove_cv<remove_reference<reference> >::type``.
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with:
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with:
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If ``Reference`` is ``use_default`` then the ``reference`` member of
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``transform_iterator`` is
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``result_of<UnaryFunction(iterator_traits<Iterator>::reference)>::type``.
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Otherwise, ``reference`` is ``Reference``.
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If ``Reference`` is ``use_default`` then the ``reference`` member of
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``transform_iterator`` is
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``result_of<UnaryFunction(iterator_traits<Iterator>::reference)>::type``.
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Otherwise, ``reference`` is ``Reference``.
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If ``Value`` is ``use_default`` then the ``value_type`` member is
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``remove_cv<remove_reference<reference> >::type``. Otherwise,
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``value_type`` is ``Value``.
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If ``Value`` is ``use_default`` then the ``value_type`` member is
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``remove_cv<remove_reference<reference> >::type``. Otherwise,
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``value_type`` is ``Value``.
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filter_iterator details unspecified
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@ -1123,18 +1105,17 @@ arguments. The only specification for any of these in the details is:
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Needs more.
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:Proposed resolution:
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Add to the synopsis::
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Add to the synopsis::
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typedef iterator_traits<Iterator>::value_type value_type;
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typedef iterator_traits<Iterator>::reference reference;
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typedef iterator_traits<Iterator>::pointer pointer;
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typedef iterator_traits<Iterator>::difference_type difference_type;
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typedef /* see below */ iterator_category;
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typedef iterator_traits<Iterator>::value_type value_type;
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typedef iterator_traits<Iterator>::reference reference;
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typedef iterator_traits<Iterator>::pointer pointer;
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typedef iterator_traits<Iterator>::difference_type difference_type;
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typedef /* see below */ iterator_category;
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and add just after the synopsis:
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and add just after the synopsis:
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If ``Iterator`` models Readable Lvalue Iterator and Forward Traversal
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Iterator then ``iterator_category`` is convertible to
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``std::forward_iterator_tag``. Otherwise ``iterator_category`` is
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convertible to ``std::input_iterator_tag``.
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If ``Iterator`` models Readable Lvalue Iterator and Forward Traversal
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Iterator then ``iterator_category`` is convertible to
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``std::forward_iterator_tag``. Otherwise ``iterator_category`` is
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convertible to ``std::input_iterator_tag``.
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