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| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="range.concepts.bidirectional_range"></a><a class="link" href="bidirectional_range.html" title="Bidirectional Range">Bidirectional Range</a> |
| </h3></div></div></div> |
| <a name="range.concepts.bidirectional_range.notation"></a><h5> |
| <a name="id762089"></a> |
| <a class="link" href="bidirectional_range.html#range.concepts.bidirectional_range.notation">Notation</a> |
| </h5> |
| <div class="informaltable"><table class="table"> |
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| <thead><tr></tr></thead> |
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| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">X</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| A type that is a model of <a class="link" href="bidirectional_range.html" title="Bidirectional Range">Bidirectional |
| Range</a>. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">a</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Object of type X. |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <a name="range.concepts.bidirectional_range.description"></a><h5> |
| <a name="id762184"></a> |
| <a class="link" href="bidirectional_range.html#range.concepts.bidirectional_range.description">Description</a> |
| </h5> |
| <p> |
| This concept provides access to iterators that traverse in both directions |
| (forward and reverse). The <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">range_iterator</span><span class="special"><</span><span class="identifier">X</span><span class="special">>::</span><span class="identifier">type</span></code> iterator must meet all of the requirements |
| of <a href="../../../../../../libs/iterator/doc/new-iter-concepts.html#bidirectional-traversal-iterators-lib-bidirectional-traversal-iterators" target="_top">Bidirectional |
| Traversal Iterator</a>. |
| </p> |
| <a name="range.concepts.bidirectional_range.refinement_of"></a><h5> |
| <a name="id762247"></a> |
| <a class="link" href="bidirectional_range.html#range.concepts.bidirectional_range.refinement_of">Refinement |
| of</a> |
| </h5> |
| <p> |
| <a class="link" href="forward_range.html" title="Forward Range">Forward Range</a> |
| </p> |
| <a name="range.concepts.bidirectional_range.associated_types"></a><h5> |
| <a name="id762274"></a> |
| <a class="link" href="bidirectional_range.html#range.concepts.bidirectional_range.associated_types">Associated |
| types</a> |
| </h5> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr></tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| Reverse Iterator type |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">range_reverse_iterator</span><span class="special"><</span><span class="identifier">X</span><span class="special">>::</span><span class="identifier">type</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| The type of iterator used to iterate through a Range's elements |
| in reverse order. The iterator's value type is expected to be the |
| Range's value type. A conversion from the reverse iterator type |
| to the const reverse iterator type must exist. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| Const reverse iterator type |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">range_reverse_iterator</span><span class="special"><</span><span class="keyword">const</span> <span class="identifier">X</span><span class="special">>::</span><span class="identifier">type</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| A type of reverse iterator that may be used to examine, but not |
| to modify, a Range's elements. |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <a name="range.concepts.bidirectional_range.valid_expressions"></a><h5> |
| <a name="id762436"></a> |
| <a class="link" href="bidirectional_range.html#range.concepts.bidirectional_range.valid_expressions">Valid |
| expressions</a> |
| </h5> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| <col> |
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| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| Name |
| </p> |
| </th> |
| <th> |
| <p> |
| Expression |
| </p> |
| </th> |
| <th> |
| <p> |
| Return type |
| </p> |
| </th> |
| <th> |
| <p> |
| Semantics |
| </p> |
| </th> |
| </tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| Beginning of range |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rbegin</span><span class="special">(</span><span class="identifier">a</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">range_reverse_iterator</span><span class="special"><</span><span class="identifier">X</span><span class="special">>::</span><span class="identifier">type</span></code> if <code class="computeroutput"><span class="identifier">a</span></code> |
| is mutable <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">range_reverse_iterator</span><span class="special"><</span><span class="keyword">const</span> |
| <span class="identifier">X</span><span class="special">>::</span><span class="identifier">type</span></code> otherwise. |
| </p> |
| </td> |
| <td> |
| <p> |
| Equivalent to <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">range_reverse_iterator</span><span class="special"><</span><span class="identifier">X</span><span class="special">>::</span><span class="identifier">type</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">end</span><span class="special">(</span><span class="identifier">a</span><span class="special">))</span></code>. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| End of range |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rend</span><span class="special">(</span><span class="identifier">a</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">range_reverse_iterator</span><span class="special"><</span><span class="identifier">X</span><span class="special">>::</span><span class="identifier">type</span></code> if <code class="computeroutput"><span class="identifier">a</span></code> |
| is mutable, <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">range_reverse_iterator</span><span class="special"><</span><span class="keyword">const</span> |
| <span class="identifier">X</span><span class="special">>::</span><span class="identifier">type</span></code> otherwise. |
| </p> |
| </td> |
| <td> |
| <p> |
| Equivalent to <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">range_reverse_iterator</span><span class="special"><</span><span class="identifier">X</span><span class="special">>::</span><span class="identifier">type</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">begin</span><span class="special">(</span><span class="identifier">a</span><span class="special">))</span></code>. |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <a name="range.concepts.bidirectional_range.complexity_guarantees"></a><h5> |
| <a name="id762894"></a> |
| <a class="link" href="bidirectional_range.html#range.concepts.bidirectional_range.complexity_guarantees">Complexity |
| guarantees</a> |
| </h5> |
| <p> |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rbegin</span><span class="special">(</span><span class="identifier">a</span><span class="special">)</span></code> has |
| the same complexity as <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">end</span><span class="special">(</span><span class="identifier">a</span><span class="special">)</span></code> and |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rend</span><span class="special">(</span><span class="identifier">a</span><span class="special">)</span></code> has the same complexity as <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">begin</span><span class="special">(</span><span class="identifier">a</span><span class="special">)</span></code> from |
| <a class="link" href="forward_range.html" title="Forward Range">Forward Range</a>. |
| </p> |
| <a name="range.concepts.bidirectional_range.invariants"></a><h5> |
| <a name="id763034"></a> |
| <a class="link" href="bidirectional_range.html#range.concepts.bidirectional_range.invariants">Invariants</a> |
| </h5> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr></tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| Valid reverse range |
| </p> |
| </td> |
| <td> |
| <p> |
| For any Bidirectional Range a, <code class="computeroutput"><span class="special">[</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rbegin</span><span class="special">(</span><span class="identifier">a</span><span class="special">),</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rend</span><span class="special">(</span><span class="identifier">a</span><span class="special">))</span></code> |
| is a valid range, that is, <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rend</span><span class="special">(</span><span class="identifier">a</span><span class="special">)</span></code> is reachable from <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rbegin</span><span class="special">(</span><span class="identifier">a</span><span class="special">)</span></code> |
| in a finite number of increments. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| Completeness |
| </p> |
| </td> |
| <td> |
| <p> |
| An algorithm that iterates through the range <code class="computeroutput"><span class="special">[</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rbegin</span><span class="special">(</span><span class="identifier">a</span><span class="special">),</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rend</span><span class="special">(</span><span class="identifier">a</span><span class="special">))</span></code> |
| will pass through every element of <code class="computeroutput"><span class="identifier">a</span></code>. |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <a name="range.concepts.bidirectional_range.see_also"></a><h5> |
| <a name="id763287"></a> |
| <a class="link" href="bidirectional_range.html#range.concepts.bidirectional_range.see_also">See also</a> |
| </h5> |
| <p> |
| <a class="link" href="../reference/concept_implementation/semantics/metafunctions.html" title="Metafunctions">Implementation |
| of metafunctions</a> |
| </p> |
| <p> |
| <a class="link" href="../reference/concept_implementation/semantics/functions.html" title="Functions">Implementation |
| of functions</a> |
| </p> |
| </div> |
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| <td align="left"></td> |
| <td align="right"><div class="copyright-footer">Copyright © 2003 -2010 Thorsten Ottosen, Neil Groves<p> |
| Distributed under the Boost Software License, Version 1.0. (See accompanying |
| file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) |
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