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| <div class="section boost_icl_interface_required_concepts" lang="en"> |
| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="boost_icl.interface.required_concepts"></a><a class="link" href="required_concepts.html" title="Required Concepts">Required Concepts</a> |
| </h3></div></div></div> |
| <p> |
| There are uniform requirements for the template parameters across <span class="bold"><strong>icl's</strong></span> class templates. The template parameters can |
| be grouped with respect to those requirements. |
| </p> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| <col> |
| <col> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| </p> |
| </th> |
| <th> |
| <p> |
| used in |
| </p> |
| </th> |
| <th> |
| <p> |
| Kind |
| </p> |
| </th> |
| <th> |
| <p> |
| Parameter |
| </p> |
| </th> |
| <th> |
| <p> |
| Instance |
| </p> |
| </th> |
| <th> |
| <p> |
| Description |
| </p> |
| </th> |
| </tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| Domain order |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Intervals</span><span class="special">,</span> |
| <span class="identifier">Sets</span><span class="special">,</span> |
| <span class="identifier">Maps</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="keyword">typename</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">DomainT</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| For the type <code class="computeroutput"><span class="identifier">DomainT</span></code> |
| of key elements <code class="computeroutput"><span class="special">...</span></code> |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="keyword">template</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Compare</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Compare</span><span class="special"><</span><span class="identifier">DomainT</span><span class="special">></span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="special">...</span></code> there is an order |
| <code class="computeroutput"><span class="identifier">Compare</span></code> |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| Interval type |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">interval_sets</span><span class="special">/</span><span class="identifier">maps</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="keyword">typename</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">IntervalT</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="special">...</span></code> the <code class="computeroutput"><span class="identifier">IntervalT</span></code> parameter has to use |
| the same element type and order. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| Codomain aggregation |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Maps</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="keyword">typename</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">CodomainT</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| For the type <code class="computeroutput"><span class="identifier">CodomainT</span></code> |
| of associated values <code class="computeroutput"><span class="special">...</span></code> |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="keyword">template</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Combine</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Combine</span><span class="special"><</span><span class="identifier">CodomainT</span><span class="special">></span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="special">...</span></code> there is a binary |
| functor <code class="computeroutput"><span class="identifier">Combine</span><span class="special"><</span><span class="identifier">CodomainT</span><span class="special">>()</span></code> |
| to combine them |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Inverse</span><span class="special"><</span><span class="identifier">Combine</span><span class="special"><</span><span class="identifier">CodomainT</span><span class="special">>></span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="special">...</span></code> and implicitly an |
| <code class="computeroutput"><span class="identifier">Inverse</span></code> functor to |
| inversely combine them. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="keyword">template</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Section</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Section</span><span class="special"><</span><span class="identifier">CodomainT</span><span class="special">></span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Intersection is propagated to CodomainT values via functor <code class="computeroutput"><span class="identifier">Section</span><span class="special"><</span><span class="identifier">CodomainT</span><span class="special">>()</span></code> |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| Memory allocation |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Sets</span><span class="special">,</span> |
| <span class="identifier">Maps</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="keyword">template</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Alloc</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Alloc</span><span class="special"><</span></code><span class="emphasis"><em>various</em></span><code class="computeroutput"><span class="special">></span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| An allocator can be chosen for memory allocation. |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <a name="boost_icl.interface.required_concepts.requirements_on_domaint"></a><h5> |
| <a name="id1107523"></a> |
| <a class="link" href="required_concepts.html#boost_icl.interface.required_concepts.requirements_on_domaint">Requirements |
| on DomainT</a> |
| </h5> |
| <p> |
| The next table gives an overview over the requirements for template parameter |
| <code class="computeroutput"><span class="identifier">DomainT</span></code>. Some requirements |
| are dependent on <span class="emphasis"><em>conditions</em></span>. Column <span class="emphasis"><em>operators</em></span> |
| shows the operators and functions that are expected for <code class="computeroutput"><span class="identifier">DomainT</span></code>, |
| if the default order <code class="computeroutput"><span class="identifier">Compare</span> <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">less</span></code> is used. |
| </p> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| Parameter |
| </p> |
| </th> |
| <th> |
| <p> |
| Condition |
| </p> |
| </th> |
| <th> |
| <p> |
| Operators |
| </p> |
| </th> |
| <th> |
| <p> |
| Requirement |
| </p> |
| </th> |
| </tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">DomainT</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">DomainT</span><span class="special">(),</span> |
| <span class="special"><</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Regular</span><span class="special"><</span><span class="identifier">DomainT</span><span class="special">></span> |
| <span class="special">&&</span> <span class="identifier">StrictWeakOrdering</span><span class="special"><</span><span class="identifier">DomainT</span><span class="special">,</span><span class="identifier">Compare</span><span class="special">></span></code> |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="special">++,</span> <span class="identifier">unit_element</span><span class="special"><</span><span class="identifier">CodomainT</span><span class="special">>::</span><span class="identifier">value</span><span class="special">()</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="special">&&</span> <span class="special">(</span><span class="identifier">IsIncrementable</span><span class="special"><</span><span class="identifier">DomainT</span><span class="special">>||</span><span class="identifier">HasUnitElement</span><span class="special"><</span><span class="identifier">DomainT</span><span class="special">>)</span></code> |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">IsIntegral</span><span class="special"><</span><span class="identifier">DomainT</span><span class="special">></span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="special">++,</span> <span class="special">--</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">IsIncrementable</span><span class="special"><</span><span class="identifier">DomainT</span><span class="special">></span> |
| <span class="special">&&</span> <span class="identifier">IsDecrementable</span><span class="special"><</span><span class="identifier">DomainT</span><span class="special">></span></code> |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <p> |
| A domain type <code class="computeroutput"><span class="identifier">DomainT</span></code> for |
| intervals and interval containers has to satisfy the requirements of concept |
| <a href="http://www.informit.com/guides/content.aspx?g=cplusplus&seqNum=314" target="_top"><code class="computeroutput"><span class="identifier">Regular</span></code></a> which implies among other |
| properties the existence of a copy and a default constructor. In addition |
| <code class="computeroutput"><span class="identifier">IsIncrementable</span></code> <span class="bold"><strong>or</strong></span> <code class="computeroutput"><span class="identifier">HasUnitElement</span></code> |
| is required for <code class="computeroutput"><span class="identifier">DomainT</span></code>. |
| In the <span class="bold"><strong>icl</strong></span> we represent an empty closed |
| interval as interval <code class="computeroutput"><span class="special">[</span><span class="identifier">b</span><span class="special">,</span><span class="identifier">a</span><span class="special">]</span></code> |
| where <code class="computeroutput"><span class="identifier">a</span> <span class="special"><</span> |
| <span class="identifier">b</span></code> (here <code class="computeroutput"><span class="special"><</span></code> |
| represents <code class="computeroutput"><span class="identifier">Compare</span><span class="special"><</span><span class="identifier">DomainT</span><span class="special">>()</span></code>). |
| To construct one of these empty intervals as default constructor for any |
| type <code class="computeroutput"><span class="identifier">DomainT</span></code> we choose <code class="computeroutput"><span class="special">[</span><span class="number">1</span><span class="special">,</span><span class="number">0</span><span class="special">]</span></code>, where |
| <code class="computeroutput"><span class="number">0</span></code> is a null-value or <code class="computeroutput"><span class="identifier">identity_element</span></code> and <code class="computeroutput"><span class="number">1</span></code> |
| is a one-value or <code class="computeroutput"><span class="identifier">unit_element</span></code>: |
| |
| </p> |
| <pre class="programlisting"><span class="identifier">interval</span><span class="special">()</span> <span class="special">:=</span> <span class="special">[</span><span class="identifier">unit_element</span><span class="special"><</span><span class="identifier">DomainT</span><span class="special">>::</span><span class="identifier">value</span><span class="special">(),</span> <span class="identifier">identity_element</span><span class="special"><</span><span class="identifier">DomainT</span><span class="special">>::</span><span class="identifier">value</span><span class="special">()]</span> <span class="comment">//pseudocode |
| </span></pre> |
| <p> |
| <code class="computeroutput"><span class="identifier">Identity_elements</span></code> are implemented |
| via call of the default constructor of <code class="computeroutput"><span class="identifier">DomainT</span></code>. |
| A <code class="computeroutput"><span class="identifier">unit_element</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span><span class="special">()</span></code> |
| is implemented <code class="computeroutput">by default</code> |
| as a <code class="computeroutput"><span class="identifier">identity_element</span></code>, that |
| is incremented once. |
| </p> |
| <pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">Type</span><span class="special">></span> |
| <span class="keyword">inline</span> <span class="identifier">Type</span> <span class="identifier">unit_element</span><span class="special"><</span><span class="identifier">Type</span><span class="special">>::</span><span class="identifier">value</span><span class="special">(){</span> <span class="keyword">return</span> <span class="identifier">succ</span><span class="special">(</span><span class="identifier">identity_element</span><span class="special"><</span><span class="identifier">Type</span><span class="special">>::</span><span class="identifier">value</span><span class="special">());</span> <span class="special">};</span> |
| </pre> |
| <p> |
| So a type <code class="computeroutput"><span class="identifier">DomainT</span></code> that is |
| <code class="computeroutput"><span class="identifier">incrementable</span></code> will also have |
| an <code class="computeroutput"><span class="identifier">unit_element</span></code>. If it does |
| not, a <code class="computeroutput"><span class="identifier">unit_element</span></code> can be |
| provided. A <code class="computeroutput"><span class="identifier">unit_element</span></code> |
| can be any value, that is greater as the <code class="computeroutput"><span class="identifier">identity_element</span></code> |
| in the <code class="computeroutput"><span class="identifier">Compare</span></code> order given. |
| An example of a type, that has an <code class="computeroutput"><span class="identifier">identity_element</span></code> |
| but no increment operation is <code class="computeroutput"><span class="identifier">string</span></code>. |
| So for <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span></code> a unit_element is implemented like |
| this: |
| </p> |
| <pre class="programlisting"><span class="comment">// Smallest 'visible' string that is greater than the empty string. |
| </span><span class="keyword">template</span> <span class="special"><></span> |
| <span class="keyword">inline</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">unit_element</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">>::</span><span class="identifier">value</span><span class="special">(){</span> <span class="keyword">return</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">(</span><span class="string">" "</span><span class="special">);</span> <span class="special">};</span> |
| </pre> |
| <p> |
| </p> |
| <p> |
| Just as for the key type of std::sets and maps template parameter <code class="computeroutput"><span class="identifier">Compare</span></code> is required to be a <a href="http://en.wikipedia.org/wiki/Strict_weak_ordering" target="_top">strict |
| weak ordering</a> on <code class="computeroutput"><span class="identifier">DomainT</span></code>. |
| </p> |
| <p> |
| Finally, if <code class="computeroutput"><span class="identifier">DomainT</span></code> is an |
| integral type, <code class="computeroutput"><span class="identifier">DomainT</span></code> needs |
| to be <code class="computeroutput"><span class="identifier">incrementable</span></code> and |
| <code class="computeroutput"><span class="identifier">decrementable</span></code>. This <span class="emphasis"><em>'bicrementability'</em></span> |
| needs to be implemented on the smallest possible unit of the integral type. |
| This seems like being trivial but there are types like e.g. <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">date_time</span><span class="special">::</span><span class="identifier">ptime</span></code>, that are integral in nature but |
| do not provide the required in- and decrementation on the least incrementable |
| unit. For <code class="computeroutput"><a class="link" href="../../boost/icl/interval.html" title="Struct template interval">icl::intervals</a></code> |
| incementation and decementation is used for computations between open to |
| closed interval borders like e.g. <code class="computeroutput"><span class="special">[</span><span class="number">2</span><span class="special">,</span><span class="number">43</span><span class="special">)</span> <span class="special">==</span> <span class="special">[</span><span class="number">2</span><span class="special">,</span><span class="number">42</span><span class="special">]</span></code>. Such computations always need only one |
| in- or decrementation, if <code class="computeroutput"><span class="identifier">DomainT</span></code> |
| is an integral type. |
| </p> |
| <a name="boost_icl.interface.required_concepts.requirements_on_intervalt"></a><h6> |
| <a name="id1108639"></a> |
| <a class="link" href="required_concepts.html#boost_icl.interface.required_concepts.requirements_on_intervalt">Requirements |
| on IntervalT</a> |
| </h6> |
| <p> |
| Requirements on the <code class="computeroutput"><span class="identifier">IntervalT</span></code> |
| parameter are closely related to the <code class="computeroutput"><span class="identifier">DomainT</span></code> |
| parameter. <code class="computeroutput"><span class="identifier">IntervalT</span></code> has |
| two associated types itself for an element type and a compare order that |
| have to be consistent with the element and order parameters of their interval |
| containers. <code class="computeroutput"><span class="identifier">IntervalT</span></code> then |
| has to implement an order called <code class="computeroutput"><span class="identifier">exclusive_less</span></code>. |
| Two intervals <code class="computeroutput"><span class="identifier">x</span><span class="special">,</span> |
| <span class="identifier">y</span></code> are exclusive_less |
| </p> |
| <pre class="programlisting"><span class="identifier">icl</span><span class="special">::</span><span class="identifier">exclusive_less</span><span class="special">(</span><span class="identifier">x</span><span class="special">,</span> <span class="identifier">y</span><span class="special">)</span></pre> |
| <p> |
| if all <code class="computeroutput"><span class="identifier">DomainT</span></code> elements of |
| <code class="computeroutput"><span class="identifier">x</span></code> are less than elements |
| of <code class="computeroutput"><span class="identifier">y</span></code> in the <code class="computeroutput"><span class="identifier">Compare</span></code> order. |
| </p> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| Parameter |
| </p> |
| </th> |
| <th> |
| <p> |
| Operators |
| </p> |
| </th> |
| <th> |
| <p> |
| Requirement |
| </p> |
| </th> |
| </tr></thead> |
| <tbody><tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">IntervalT</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">exclusive_less</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">IsExclusiveLessComparable</span><span class="special"><</span><span class="identifier">Interval</span><span class="special"><</span><span class="identifier">DomainT</span><span class="special">,</span><span class="identifier">Compare</span><span class="special">></span> <span class="special">></span></code> |
| </p> |
| </td> |
| </tr></tbody> |
| </table></div> |
| <a name="boost_icl.interface.required_concepts.requirements_on_codomaint"></a><h5> |
| <a name="id1108888"></a> |
| <a class="link" href="required_concepts.html#boost_icl.interface.required_concepts.requirements_on_codomaint">Requirements |
| on CodomainT</a> |
| </h5> |
| <p> |
| Summarized in the next table are requirements for template parameter <code class="computeroutput"><span class="identifier">CodomainT</span></code> of associated values for <code class="computeroutput"><span class="identifier">Maps</span></code>. Again there are <span class="emphasis"><em>conditions</em></span> |
| for some of the requirements. Column <span class="emphasis"><em>operators</em></span> contains |
| the operators and functions required for <code class="computeroutput"><span class="identifier">CodomainT</span></code>, |
| if we are using the default combiner <code class="computeroutput"><span class="identifier">Combine</span> |
| <span class="special">=</span> <span class="identifier">icl</span><span class="special">::</span><span class="identifier">inplace_plus</span></code>. |
| </p> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| Parameter |
| </p> |
| </th> |
| <th> |
| <p> |
| Condition |
| </p> |
| </th> |
| <th> |
| <p> |
| Operators |
| </p> |
| </th> |
| <th> |
| <p> |
| Requirement |
| </p> |
| </th> |
| </tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">CodomainT</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">add</span></code>, <code class="computeroutput"><span class="identifier">subtract</span></code>, <code class="computeroutput"><span class="identifier">intersect</span></code> |
| unused |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">CodomainT</span><span class="special">(),</span> |
| <span class="special">==</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Regular</span><span class="special"><</span><span class="identifier">CodomainT</span><span class="special">></span></code> |
| which implies |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">DefaultConstructible</span><span class="special"><</span><span class="identifier">CodomainT</span><span class="special">></span> <span class="special">&&</span> |
| <span class="identifier">EqualityComparable</span><span class="special"><</span><span class="identifier">CodomainT</span><span class="special">></span></code> |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| only <code class="computeroutput"><span class="identifier">add</span></code> used |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="special">+=</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="special">&&</span> <span class="identifier">Combinable</span><span class="special"><</span><span class="identifier">CodomainT</span><span class="special">,</span><span class="identifier">Combine</span><span class="special">></span></code> |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| ... and also <code class="computeroutput"><span class="identifier">subtract</span></code> |
| used |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="special">-=</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="special">&&</span> <span class="identifier">Combinable</span><span class="special"><</span><span class="identifier">CodomainT</span><span class="special">,</span><span class="identifier">Inverse</span><span class="special"><</span><span class="identifier">Combine</span><span class="special">></span> <span class="special">></span></code> |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Section</span></code> used and |
| <code class="computeroutput"><span class="identifier">CodomainT</span></code> is a set |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="special">&=</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="special">&&</span> <span class="identifier">Intersectable</span><span class="special"><</span><span class="identifier">CodomainT</span><span class="special">,</span><span class="identifier">Section</span><span class="special">></span></code> |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <p> |
| The requirements on the type <code class="computeroutput"><span class="identifier">CodomainT</span></code> |
| of associated values for a <code class="computeroutput"><a class="link" href="../../boost/icl/map.html" title="Class template map">icl::map</a></code> |
| or <code class="computeroutput"><a class="link" href="../../boost/icl/interval_map.html" title="Class template interval_map">interval_map</a></code> depend |
| on the usage of their aggregation functionality. If aggregation on overlap |
| is never used, that is to say that none of the addition, subtraction and |
| intersection operations (<code class="computeroutput"><span class="special">+,</span> <span class="special">+=,</span> <span class="identifier">add</span></code>, |
| <code class="computeroutput"><span class="special">-,</span> <span class="special">-=,</span> |
| <span class="identifier">subtract</span></code>, &, &=, add_intersection) |
| are used on the <code class="computeroutput"><a class="link" href="../../boost/icl/interval_map.html" title="Class template interval_map">interval_map</a></code>, |
| then <code class="computeroutput"><span class="identifier">CodomainT</span></code> only needs |
| to be <a href="http://www.informit.com/guides/content.aspx?g=cplusplus&seqNum=314" target="_top">Regular</a>. |
| </p> |
| <p> |
| <span class="emphasis"><em><span class="bold"><strong>Regular</strong></span></em></span> object semantics |
| implies <code class="computeroutput"><span class="identifier">DefaultConstructible</span></code> |
| and <code class="computeroutput"><span class="identifier">EqualityComparable</span></code> which |
| means it has a default ctor <code class="computeroutput"><span class="identifier">CodomainT</span><span class="special">()</span></code> and an <code class="computeroutput"><span class="keyword">operator</span> |
| <span class="special">==</span></code>. |
| </p> |
| <p> |
| Use <code class="computeroutput"><a class="link" href="../../boost/icl/interval_map.html" title="Class template interval_map">interval_maps</a></code> |
| <span class="emphasis"><em><span class="bold"><strong>without aggregation</strong></span></em></span>, |
| if the associated values are not addable but still are attached to intervals |
| so you want to use <code class="computeroutput"><a class="link" href="../../boost/icl/interval_map.html" title="Class template interval_map">interval_maps</a></code> |
| to handle them. As long as those values are added with <code class="computeroutput"><span class="identifier">insert</span></code> |
| and deleted with <code class="computeroutput"><span class="identifier">erase</span></code> <code class="computeroutput"><a class="link" href="../../boost/icl/interval_map.html" title="Class template interval_map">interval_maps</a></code> will work fine with |
| such values. |
| </p> |
| <p> |
| If <span class="emphasis"><em><span class="bold"><strong>only addition</strong></span></em></span> is |
| used via <code class="computeroutput"><a class="link" href="../../boost/icl/interval_map.html" title="Class template interval_map">interval_map's</a></code> |
| <code class="computeroutput"><span class="special">+,</span> <span class="special">+=</span></code> |
| or <code class="computeroutput"><span class="identifier">add</span></code> but no subtraction, |
| then <code class="computeroutput"><span class="identifier">CodomainT</span></code> need to be |
| <code class="computeroutput"><span class="identifier">Combinable</span></code> for functor template |
| <code class="computeroutput"><span class="identifier">Combine</span></code>. That means in most |
| cases when the default implementation <code class="computeroutput"><span class="identifier">inplace_plus</span></code> |
| for <code class="computeroutput"><span class="identifier">Combine</span></code> is used, that |
| <code class="computeroutput"><span class="identifier">CodomainT</span></code> has to implement |
| <code class="computeroutput"><span class="keyword">operator</span> <span class="special">+=</span></code>. |
| </p> |
| <p> |
| For associated value types, that are addable but not subtractable like e.g. |
| <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span></code> it usually makes sense to use addition |
| to combine values but the inverse combination is not desired. |
| </p> |
| <pre class="programlisting"><span class="identifier">interval_map</span><span class="special"><</span><span class="keyword">int</span><span class="special">,</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">></span> <span class="identifier">cat_map</span><span class="special">;</span> |
| <span class="identifier">cat_map</span> <span class="special">+=</span> <span class="identifier">make_pair</span><span class="special">(</span><span class="identifier">interval</span><span class="special"><</span><span class="keyword">int</span><span class="special">>::</span><span class="identifier">rightopen</span><span class="special">(</span><span class="number">1</span><span class="special">,</span><span class="number">5</span><span class="special">),</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">(</span><span class="string">"Hello"</span><span class="special">));</span> |
| <span class="identifier">cat_map</span> <span class="special">+=</span> <span class="identifier">make_pair</span><span class="special">(</span><span class="identifier">interval</span><span class="special"><</span><span class="keyword">int</span><span class="special">>::</span><span class="identifier">rightopen</span><span class="special">(</span><span class="number">3</span><span class="special">,</span><span class="number">7</span><span class="special">),</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">(</span><span class="string">" world"</span><span class="special">));</span> |
| <span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"cat_map: "</span> <span class="special"><<</span> <span class="identifier">cat_map</span> <span class="special"><<</span> <span class="identifier">endl</span><span class="special">;</span> |
| <span class="comment">//cat_map: {([1,3)->Hello)([3,5)->Hello world)([5,7)-> world)} |
| </span></pre> |
| <p> |
| </p> |
| <p> |
| For <span class="emphasis"><em>complete aggregation functionality</em></span> an inverse aggregation |
| functor on a <code class="computeroutput"><span class="identifier">Map</span></code>'s <code class="computeroutput"><span class="identifier">CodomainT</span></code> is needed. The icl provides a |
| metafunction <code class="computeroutput"><a class="link" href="../../boost/icl/inverse.html" title="Struct template inverse">inverse</a></code> for |
| that purpose. Using the default <code class="computeroutput"><span class="identifier">Combine</span> |
| <span class="special">=</span> <span class="identifier">inplace_plus</span></code> |
| that relies on the existence of <code class="computeroutput"><span class="keyword">operator</span> |
| <span class="special">+=</span></code> on type <code class="computeroutput"><span class="identifier">CodomainT</span></code> |
| metafunction <code class="computeroutput"><a class="link" href="../../boost/icl/inverse.html" title="Struct template inverse">inverse</a></code> will |
| infer <code class="computeroutput"><a class="link" href="../../boost/icl/inplace_minus.html" title="Struct template inplace_minus">inplace_minus</a></code> |
| as inverse functor, that requires <code class="computeroutput"><span class="keyword">operator</span> |
| <span class="special">-=</span></code> on type <code class="computeroutput"><span class="identifier">CodomainT</span></code>. |
| </p> |
| <p> |
| In the icl's design we make the assumption, in particular for the default |
| setting of parameters <code class="computeroutput"><span class="identifier">Combine</span> <span class="special">=</span> </code><code class="computeroutput"><a class="link" href="../../boost/icl/inplace_minus.html" title="Struct template inplace_minus">inplace_plus</a></code>, |
| that type <code class="computeroutput"><span class="identifier">CodomainT</span></code> has a |
| neutral element or <code class="computeroutput"><span class="identifier">identity_element</span></code> |
| with respect to the <code class="computeroutput"><span class="identifier">Combine</span></code> |
| functor. |
| </p> |
| </div> |
| <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> |
| <td align="left"></td> |
| <td align="right"><div class="copyright-footer">Copyright © 2007 -2010 Joachim Faulhaber<br>Copyright © 1999 -2006 Cortex Software GmbH<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>) |
| </p> |
| </div></td> |
| </tr></table> |
| <hr> |
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