| <?xml version="1.0"?> |
| <concept name="InputIterator" category="Iterator"><!-- |
| Based on concepts from the SGI Standard Template Library documentation: |
| Copyright (c) 1996-1999 |
| Silicon Graphics Computer Systems, Inc. |
| |
| Copyright (c) 1994 |
| Hewlett-Packard Company |
| --><!-- |
| Copyright 2000-2001 University of Notre Dame du Lac. |
| Copyright 2001-2002 Indiana University. |
| Some concepts based on versions from the MTL draft manual and Boost Graph |
| and Property Map documentation: |
| Copyright (c) Jeremy Siek, Lie-Quan Lee, and Andrew Lumsdaine 2000 |
| --> |
| <param name="Iter" role="iterator-type"/> |
| |
| <use-header name="iterator"/> |
| |
| <models-sentence>The iterator type <arg num="1"/> must be a model of <self/>.</models-sentence> |
| |
| <description> |
| <para>An input iterator is an iterator that can read through a sequence of |
| values. It is single-pass (old values of the iterator cannot be |
| re-used), and read-only.</para> |
| |
| <para>An input iterator represents a position in a sequence. Therefore, the |
| iterator can point into the sequence (returning a value when dereferenced |
| and being incrementable), or be off-the-end (and not dereferenceable or |
| incrementable).</para> |
| </description> |
| |
| <refines const="no" concept="Assignable"/> |
| <refines const="no" concept="DefaultConstructible"/> |
| <refines const="no" concept="EqualityComparable"/> |
| |
| <notation variables="i j"> |
| <sample-value> |
| <type name="Iter"/> |
| </sample-value> |
| </notation> |
| |
| <associated-type name="value_type"> |
| <get-member-type name="value_type"> |
| <apply-template name="std::iterator_traits"> |
| <type name="Iter"/> |
| </apply-template> |
| </get-member-type> |
| <description><simpara>The value type of the iterator (not necessarily what |
| <code>*i</code> returns)</simpara></description> |
| </associated-type> |
| |
| <associated-type name="difference_type"> |
| <get-member-type name="difference_type"> |
| <apply-template name="std::iterator_traits"> |
| <type name="Iter"/> |
| </apply-template> |
| </get-member-type> |
| <description><simpara>The difference type of the iterator</simpara></description> |
| </associated-type> |
| |
| <associated-type name="category"> |
| <get-member-type name="iterator_category"> |
| <apply-template name="std::iterator_traits"> |
| <type name="Iter"/> |
| </apply-template> |
| </get-member-type> |
| <description><simpara>The category of the iterator</simpara></description> |
| </associated-type> |
| |
| <notation variables="x"> |
| <sample-value> |
| <type name="value_type"/> |
| </sample-value> |
| </notation> |
| |
| <valid-type-expression name="Category tag"> |
| <description/> |
| <type name="category"/> |
| <return-type> |
| <derived-from testable="yes"> |
| <type name="std::input_iterator_tag"/> |
| </derived-from> |
| <models-as-first-arg const="no" testable="yes" concept="DefaultConstructible"/> |
| <models-as-first-arg const="no" testable="yes" concept="CopyConstructible"/> |
| </return-type> |
| </valid-type-expression> |
| |
| <valid-type-expression name="Value type copy constructibility"> |
| <description/> |
| <type name="value_type"/> |
| <return-type> |
| <models-as-first-arg const="no" testable="yes" concept="CopyConstructible"/> |
| </return-type> |
| </valid-type-expression> |
| |
| <valid-type-expression name="Difference type properties"> |
| <description/> |
| <type name="difference_type"/> |
| <return-type> |
| <models-as-first-arg const="no" testable="yes" concept="SignedInteger"/> |
| </return-type> |
| </valid-type-expression> |
| |
| <valid-expression name="Dereference"> |
| <dereference> |
| <sample-value><type name="Iter"/></sample-value> |
| </dereference> |
| <return-type> |
| <convertible-to testable="yes"><type name="value_type"/></convertible-to> |
| </return-type> |
| <precondition><code>i</code> is incrementable (not |
| off-the-end)</precondition> |
| </valid-expression> |
| |
| <valid-expression name="Preincrement"> |
| <preincrement> |
| <sample-value><reference-to><type name="Iter"/></reference-to></sample-value> |
| </preincrement> |
| <return-type> |
| <require-same-type testable="yes"> |
| <reference-to><type name="Iter"/></reference-to> |
| </require-same-type> |
| </return-type> |
| <precondition><code>i</code> is incrementable (not |
| off-the-end)</precondition> |
| </valid-expression> |
| |
| <valid-expression name="Postincrement"> |
| <postincrement> |
| <sample-value><reference-to><type name="Iter"/></reference-to></sample-value> |
| </postincrement> |
| <return-type/> |
| <precondition><code>i</code> is incrementable (not |
| off-the-end)</precondition> |
| <semantics>Equivalent to <code>(void)(++i)</code></semantics> |
| <postcondition><code>i</code> is dereferenceable or |
| off-the-end</postcondition> |
| </valid-expression> |
| |
| <valid-expression name="Postincrement and dereference"> |
| <dereference> |
| <postincrement> |
| <sample-value><reference-to><type name="Iter"/></reference-to></sample-value> |
| </postincrement> |
| </dereference> |
| <return-type> |
| <convertible-to testable="yes"><type name="value_type"/></convertible-to> |
| </return-type> |
| <precondition><code>i</code> is incrementable (not |
| off-the-end)</precondition> |
| <semantics>Equivalent to <code>{value_type t = *i; ++i; return t;}</code></semantics> |
| <postcondition><code>i</code> is dereferenceable or |
| off-the-end</postcondition> |
| </valid-expression> |
| |
| <complexity> |
| All iterator operations must take amortized constant time. |
| </complexity> |
| |
| <example-model> |
| <type name="std::istream_iterator"/> |
| </example-model> |
| |
| <see-also concept="OutputIterator"/> |
| <see-also concept="ForwardIterator"/> |
| |
| </concept> |