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| <div class="section" title="converter<> function object"> |
| <div class="titlepage"><div><div><h2 class="title" style="clear: both"> |
| <a name="boost_numericconversion.converter___function_object"></a><a class="link" href="converter___function_object.html" title="converter<> function object">converter<> |
| function object</a> |
| </h2></div></div></div> |
| <div class="toc"><dl> |
| <dt><span class="section"><a href="converter___function_object.html#boost_numericconversion.converter___function_object.synopsis">Synopsis</a></span></dt> |
| <dt><span class="section"><a href="converter___function_object.html#boost_numericconversion.converter___function_object.template_parameters">Template |
| parameters</a></span></dt> |
| <dt><span class="section"><a href="converter___function_object.html#boost_numericconversion.converter___function_object.member_functions">Member |
| functions</a></span></dt> |
| <dt><span class="section"><a href="converter___function_object.html#boost_numericconversion.converter___function_object.range_checking_logic">Range |
| Checking Logic</a></span></dt> |
| <dt><span class="section"><a href="converter___function_object.html#boost_numericconversion.converter___function_object.examples">Examples</a></span></dt> |
| </dl></div> |
| <div class="section" title="Synopsis"> |
| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="boost_numericconversion.converter___function_object.synopsis"></a><a class="link" href="converter___function_object.html#boost_numericconversion.converter___function_object.synopsis" title="Synopsis">Synopsis</a> |
| </h3></div></div></div> |
| <pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span> |
| |
| |
| <span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">,</span> |
| <span class="keyword">class</span> <span class="identifier">S</span><span class="special">,</span> |
| <span class="keyword">class</span> <span class="identifier">Traits</span><span class="special">,</span> <span class="special">=</span> <span class="identifier">conversion_traits</span><span class="special"><</span><span class="identifier">T</span><span class="special">,</span><span class="identifier">S</span><span class="special">></span> |
| <span class="keyword">class</span> <span class="identifier">OverflowHandler</span> <span class="special">=</span> <span class="identifier">def_overflow_handler</span><span class="special">,</span> |
| <span class="keyword">class</span> <span class="identifier">Float2IntRounder</span> <span class="special">=</span> <span class="identifier">Trunc</span><span class="special"><</span> <span class="keyword">typename</span> <span class="identifier">Traits</span><span class="special">::</span><span class="identifier">source_type</span> <span class="special">>,</span> |
| <span class="keyword">class</span> <span class="identifier">RawConverter</span> <span class="special">=</span> <span class="identifier">raw_converter</span><span class="special"><</span><span class="identifier">Traits</span><span class="special">>,</span> |
| <span class="keyword">class</span> <span class="identifier">UserRangeChecker</span> <span class="special">=</span> <span class="identifier">UseInternalRangeChecker</span> |
| <span class="special">></span> |
| <span class="keyword">struct</span> <span class="identifier">converter</span> |
| <span class="special">{</span> |
| <span class="keyword">typedef</span> <span class="identifier">Traits</span> <span class="identifier">traits</span> <span class="special">;</span> |
| |
| <span class="keyword">typedef</span> <span class="keyword">typename</span> <span class="identifier">Traits</span><span class="special">::</span><span class="identifier">source_type</span> <span class="identifier">source_type</span> <span class="special">;</span> |
| <span class="keyword">typedef</span> <span class="keyword">typename</span> <span class="identifier">Traits</span><span class="special">::</span><span class="identifier">argument_type</span> <span class="identifier">argument_type</span> <span class="special">;</span> |
| <span class="keyword">typedef</span> <span class="keyword">typename</span> <span class="identifier">Traits</span><span class="special">::</span><span class="identifier">result_type</span> <span class="identifier">result_type</span> <span class="special">;</span> |
| |
| <span class="keyword">static</span> <span class="identifier">result_type</span> <span class="identifier">convert</span> <span class="special">(</span> <span class="identifier">argument_type</span> <span class="identifier">s</span> <span class="special">)</span> <span class="special">;</span> |
| |
| <span class="identifier">result_type</span> <span class="keyword">operator</span><span class="special">()</span> <span class="special">(</span> <span class="identifier">argument_type</span> <span class="identifier">s</span> <span class="special">)</span> <span class="keyword">const</span> <span class="special">;</span> |
| |
| <span class="comment">// Internal member functions: |
| </span> |
| <span class="keyword">static</span> <span class="identifier">range_check_result</span> <span class="identifier">out_of_range</span> <span class="special">(</span> <span class="identifier">argument_type</span> <span class="identifier">s</span> <span class="special">)</span> <span class="special">;</span> |
| <span class="keyword">static</span> <span class="keyword">void</span> <span class="identifier">validate_range</span> <span class="special">(</span> <span class="identifier">argument_type</span> <span class="identifier">s</span> <span class="special">)</span> <span class="special">;</span> |
| <span class="keyword">static</span> <span class="identifier">result_type</span> <span class="identifier">low_level_convert</span> <span class="special">(</span> <span class="identifier">argument_type</span> <span class="identifier">s</span> <span class="special">)</span> <span class="special">;</span> |
| <span class="keyword">static</span> <span class="identifier">source_type</span> <span class="identifier">nearbyint</span> <span class="special">(</span> <span class="identifier">argument_type</span> <span class="identifier">s</span> <span class="special">)</span> <span class="special">;</span> |
| |
| <span class="special">}</span> <span class="special">;</span> |
| |
| <span class="special">}</span> <span class="special">}</span> <span class="comment">// namespace numeric, boost |
| </span></pre> |
| <p> |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">converter</span><span class="special"><></span></code> |
| is a <a href="http://www.sgi.com/tech/stl/UnaryFunction.html" target="_top">Unary Function |
| Object</a> encapsulating the code to perform a numeric conversion with |
| the direction and properties specified by the Traits template parameter. |
| It can optionally take some <a class="link" href="numeric_converter_policy_classes.html" title="Numeric Converter Policy Classes">policies</a> |
| which can be used to customize its behavior. The <code class="computeroutput"><span class="identifier">Traits</span></code> |
| parameter is not a policy but the parameter that defines the conversion. |
| </p> |
| </div> |
| <div class="section" title="Template parameters"> |
| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="boost_numericconversion.converter___function_object.template_parameters"></a><a class="link" href="converter___function_object.html#boost_numericconversion.converter___function_object.template_parameters" title="Template parameters">Template |
| parameters</a> |
| </h3></div></div></div> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| </p> |
| </th> |
| <th> |
| <p> |
| </p> |
| </th> |
| </tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">T</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| The <a class="link" href="definitions.html#boost_numericconversion.definitions.numeric_types" title="Numeric Types">Numeric |
| Type</a> which is the <span class="emphasis"><em>Target</em></span> of the conversion. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">S</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| The <a class="link" href="definitions.html#boost_numericconversion.definitions.numeric_types" title="Numeric Types">Numeric |
| Type</a> which is the <span class="emphasis"><em>Source</em></span> of the conversion. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Traits</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| This must be a conversion traits class with the interface of <a class="link" href="conversion_traits___traits_class.html" title="conversion_traits<> traits class"><code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">conversion_traits</span></code></a> |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">OverflowHandler</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <span class="bold"><strong>Stateless Policy</strong></span> called to administrate |
| the result of the range checking. |
| </p> |
| <p> |
| It is a <span class="bold"><strong>Function Object</strong></span> which receives |
| the result of <code class="computeroutput"><span class="identifier">out_of_range</span><span class="special">()</span></code> and is called inside the <code class="computeroutput"><span class="identifier">validate_range</span><span class="special">()</span></code> |
| static member function exposed by the converter. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Float2IntRounder</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <span class="bold"><strong>Stateless Policy</strong></span> which specifies |
| the rounding mode used for float to integral conversions. |
| </p> |
| <p> |
| It supplies the <code class="computeroutput"><span class="identifier">nearbyint</span><span class="special">()</span></code> static member function exposed |
| by the converter. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">RawConverter</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <span class="bold"><strong>Stateless Policy</strong></span> which is used to |
| perform the actual conversion. |
| </p> |
| <p> |
| It supplies the <code class="computeroutput"><span class="identifier">low_level_convert</span><span class="special">()</span></code> static member function exposed |
| by the converter. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">UserRangeChecker</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <span class="emphasis"><em>Special and Optional</em></span> <span class="bold"><strong>Stateless |
| Policy</strong></span> which can be used to override the internal range |
| checking logic. |
| </p> |
| <p> |
| If given, supplies alternative code for the <code class="computeroutput"><span class="identifier">out_of_range</span><span class="special">()</span></code> and <code class="computeroutput"><span class="identifier">validate_range</span><span class="special">()</span></code> static member functions exposed |
| by the converter. |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <div class="section" title="Member functions"> |
| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="boost_numericconversion.converter___function_object.member_functions"></a><a class="link" href="converter___function_object.html#boost_numericconversion.converter___function_object.member_functions" title="Member functions">Member |
| functions</a> |
| </h3></div></div></div> |
| <div class="blockquote"><blockquote class="blockquote"> |
| <p> |
| </p> |
| <p> |
| <code class="computeroutput"><span class="keyword">static</span> <span class="identifier">result_type</span> |
| <span class="identifier">converter</span><span class="special"><>::</span><span class="identifier">convert</span> <span class="special">(</span> |
| <span class="identifier">argument_type</span> <span class="identifier">s</span> |
| <span class="special">)</span> <span class="special">;</span> |
| <span class="comment">// throw </span></code> |
| </p> |
| <p> |
| </p> |
| </blockquote></div> |
| <p> |
| This static member function converts an rvalue of type <code class="computeroutput"><span class="identifier">source_type</span></code> |
| to an rvalue of type <code class="computeroutput"><span class="identifier">target_type</span></code>. |
| </p> |
| <p> |
| If the conversion requires it, it performs a range checking before the conversion |
| and passes the result of the check to the overflow handler policy (the default |
| policy throws an exception if out-of-range is detected) |
| </p> |
| <p> |
| The implementation of this function is actually built from the policies and |
| is basically as follows: |
| </p> |
| <pre class="programlisting"><span class="identifier">result_type</span> <span class="identifier">converter</span><span class="special"><>::</span><span class="identifier">convert</span> <span class="special">(</span> <span class="identifier">argument_type</span> <span class="identifier">s</span> <span class="special">)</span> |
| <span class="special">{</span> |
| <span class="identifier">validate_range</span><span class="special">(</span><span class="identifier">s</span><span class="special">);</span> <span class="comment">// Implemented by the internal range checking logic |
| </span> <span class="comment">// (which also calls the OverflowHandler policy) |
| </span> <span class="comment">// or externally supplied by the UserRangeChecker policy. |
| </span> |
| <span class="identifier">s</span> <span class="special">=</span> <span class="identifier">nearbyint</span><span class="special">(</span><span class="identifier">s</span><span class="special">);</span> <span class="comment">// Externally supplied by the Float2IntRounder policy. |
| </span> <span class="comment">// NOTE: This is actually called only for float to int conversions. |
| </span> |
| <span class="keyword">return</span> <span class="identifier">low_level_convert</span><span class="special">(</span><span class="identifier">s</span><span class="special">);</span> <span class="comment">// Externally supplied by the RawConverter policy. |
| </span><span class="special">}</span> |
| </pre> |
| <p> |
| <code class="computeroutput"><span class="identifier">converter</span><span class="special"><>::</span><span class="keyword">operator</span><span class="special">()</span> <span class="keyword">const</span></code> just calls <code class="computeroutput"><span class="identifier">convert</span><span class="special">()</span></code> |
| </p> |
| <p> |
| <span class="inlinemediaobject"><img src="../images/space.png" alt="space"></span> |
| </p> |
| <div class="blockquote"><blockquote class="blockquote"> |
| <p> |
| </p> |
| <p> |
| <code class="computeroutput"><span class="keyword">static</span> <span class="identifier">range_check_result</span> |
| <span class="identifier">numeric_converter</span><span class="special"><>::</span><span class="identifier">out_of_range</span> <span class="special">(</span> |
| <span class="identifier">argument_type</span> <span class="identifier">s</span> |
| <span class="special">)</span> <span class="special">;</span></code> |
| </p> |
| <p> |
| </p> |
| </blockquote></div> |
| <p> |
| This <a class="link" href="converter___function_object.html#numeric_conversion_converter_internal">internal</a> |
| static member function determines if the value <code class="computeroutput"><span class="identifier">s</span></code> |
| can be represented by the target type without overflow. |
| </p> |
| <p> |
| It does not determine if the conversion is <span class="emphasis"><em>exact</em></span>; that |
| is, it does not detect <span class="emphasis"><em>inexact</em></span> conversions, only <span class="emphasis"><em>out-of-range</em></span> |
| conversions (see the <a class="link" href="definitions.html#boost_numericconversion.definitions.exact__correctly_rounded_and_out_of_range_representations" title="Exact, Correctly Rounded and Out-Of-Range Representations">Definitions</a> |
| for further details). |
| </p> |
| <p> |
| The return value is of enum type <a class="link" href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.enum_range_check_result" title="enum range_check_result"><code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">range_check_result</span></code></a> |
| </p> |
| <p> |
| The actual code for the range checking logic is optimized for the combined |
| properties of the source and target types. For example, a non-subranged conversion |
| (i.e: <code class="computeroutput"><span class="keyword">int</span></code>-><code class="computeroutput"><span class="keyword">float</span></code>), requires no range checking, so <code class="computeroutput"><span class="identifier">out_of_range</span><span class="special">()</span></code> |
| returns <code class="computeroutput"><span class="identifier">cInRange</span></code> directly. |
| See the following <a class="link" href="converter___function_object.html#boost_numericconversion.converter___function_object.range_checking_logic" title="Range Checking Logic">table</a> |
| for more details. |
| </p> |
| <p> |
| If the user supplied a <a class="link" href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_userrangechecker" title="Policy UserRangeChecker">UserRangeChecker</a> |
| policy, is this policy which implements this function, so the implementation |
| is user defined, although it is expected to perform the same conceptual check |
| and return the appropriate result. |
| </p> |
| <p> |
| <span class="inlinemediaobject"><img src="../images/space.png" alt="space"></span> |
| </p> |
| <div class="blockquote"><blockquote class="blockquote"> |
| <p> |
| </p> |
| <p> |
| <code class="computeroutput"><span class="keyword">static</span> <span class="keyword">void</span> |
| <span class="identifier">numeric_converter</span><span class="special"><>::</span><span class="identifier">validate_range</span> <span class="special">(</span> |
| <span class="identifier">argument_type</span> <span class="identifier">s</span> |
| <span class="special">)</span> <span class="special">;</span> |
| <span class="comment">// no throw </span></code> |
| </p> |
| <p> |
| </p> |
| </blockquote></div> |
| <p> |
| This <a class="link" href="converter___function_object.html#numeric_conversion_converter_internal">internal</a> |
| static member function calls out_of_range(s), and passes the result to the |
| <a class="link" href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_overflowhandler" title="Policy OverflowHandler">OverflowHandler</a> |
| policy class. |
| </p> |
| <p> |
| For those Target/Source combinations which don't require range checking, |
| this is an empty inline function. |
| </p> |
| <p> |
| If the user supplied a <a class="link" href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_userrangechecker" title="Policy UserRangeChecker">UserRangeChecker</a> |
| policy, is this policy which implements this function, so the implementation |
| is user defined, although it is expected to perform the same action as the |
| default. In particular, it is expected to pass the result of the check to |
| the overflow handler. |
| </p> |
| <p> |
| <span class="inlinemediaobject"><img src="../images/space.png" alt="space"></span> |
| </p> |
| <div class="blockquote"><blockquote class="blockquote"> |
| <p> |
| </p> |
| <p> |
| <code class="computeroutput"><span class="keyword">static</span> <span class="identifier">result_type</span> |
| <span class="identifier">numeric_converter</span><span class="special"><>::</span><span class="identifier">low_level_convert</span> <span class="special">(</span> |
| <span class="identifier">argument_type</span> <span class="identifier">s</span> |
| <span class="special">)</span> <span class="special">;</span></code> |
| </p> |
| <p> |
| </p> |
| </blockquote></div> |
| <p> |
| This <a class="link" href="converter___function_object.html#numeric_conversion_converter_internal">internal</a> |
| static member function performs the actual conversion. |
| </p> |
| <p> |
| This function is externally supplied by the <a class="link" href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_rawconverter" title="Policy RawConverter">RawConverter</a> |
| policy class. |
| </p> |
| <p> |
| <span class="inlinemediaobject"><img src="../images/space.png" alt="space"></span> |
| </p> |
| <div class="blockquote"><blockquote class="blockquote"> |
| <p> |
| </p> |
| <p> |
| <code class="computeroutput"><span class="keyword">static</span> <span class="identifier">source_type</span> |
| <span class="identifier">converter</span><span class="special"><>::</span><span class="identifier">nearbyint</span> <span class="special">(</span> |
| <span class="identifier">argument_type</span> <span class="identifier">s</span> |
| <span class="special">)</span> <span class="special">;</span></code> |
| </p> |
| <p> |
| </p> |
| </blockquote></div> |
| <p> |
| This <a class="link" href="converter___function_object.html#numeric_conversion_converter_internal">internal</a> |
| static member function, which is <span class="underline">only used</span> |
| for <code class="computeroutput"><span class="keyword">float</span></code> to <code class="computeroutput"><span class="keyword">int</span></code> |
| conversions, returns an <span class="emphasis"><em>integer</em></span> value of <span class="emphasis"><em><span class="underline">floating-point type</span></em></span> according to some |
| rounding direction. |
| </p> |
| <p> |
| This function is externally supplied by the <a class="link" href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_float2introunder" title="Policy Float2IntRounder">Float2IntRounder</a> |
| policy class which encapsulates the specific rounding mode. |
| </p> |
| <p> |
| <span class="inlinemediaobject"><img src="../images/space.png" alt="space"></span> |
| </p> |
| <a name="numeric_conversion_converter_internal"></a><p> |
| </p> |
| <a name="boost_numericconversion.converter___function_object.member_functions.internal_member_functions"></a><h5> |
| <a name="id563268"></a> |
| <a class="link" href="converter___function_object.html#boost_numericconversion.converter___function_object.member_functions.internal_member_functions">Internal |
| Member Functions</a> |
| </h5> |
| <p> |
| These static member functions build the actual conversion code used by <code class="computeroutput"><span class="identifier">convert</span><span class="special">()</span></code>. |
| The user does not have to call these if calling <code class="computeroutput"><span class="identifier">convert</span><span class="special">()</span></code>, since <code class="computeroutput"><span class="identifier">convert</span><span class="special">()</span></code> calls them infernally, but they can be |
| called separately for specific needs. |
| </p> |
| </div> |
| <div class="section" title="Range Checking Logic"> |
| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="boost_numericconversion.converter___function_object.range_checking_logic"></a><a class="link" href="converter___function_object.html#boost_numericconversion.converter___function_object.range_checking_logic" title="Range Checking Logic">Range |
| Checking Logic</a> |
| </h3></div></div></div> |
| <p> |
| The following table summarizes the internal range checking logic performed |
| for each combination of the properties of Source and Target. |
| </p> |
| <p> |
| LowestT/HighestT denotes the highest and lowest values of the Target type, |
| respectively. |
| </p> |
| <p> |
| <code class="computeroutput"><span class="identifier">S</span><span class="special">(</span><span class="identifier">n</span><span class="special">)</span></code> is short |
| for <code class="computeroutput"><span class="keyword">static_cast</span><span class="special"><</span><span class="identifier">S</span><span class="special">>(</span><span class="identifier">n</span><span class="special">)</span></code> (<code class="computeroutput"><span class="identifier">S</span></code> denotes the Source type). |
| </p> |
| <p> |
| <code class="computeroutput"><span class="identifier">NONE</span></code> indicates that for this |
| case there is no range checking. |
| </p> |
| <pre class="programlisting"><code class="literal"> |
| int_to_int |--> sig_to_sig |--> subranged |--> ( s >= S(LowestT) ) && ( s <= S(HighestT) ) |
| | |--> not subranged |--> NONE |
| | |
| |--> unsig_to_unsig |--> subranged |--> ( s >= S(LowestT) ) && ( s <= S(HighestT) ) |
| | |--> not subranged |--> NONE |
| | |
| |--> sig_to_unsig |--> pos subranged |--> ( s >= S(0) ) && ( s <= S(HighestT) ) |
| | |--> not pos subranged |--> ( s >= S(0) ) |
| | |
| |--> unsig_to_sig |--> subranged |--> ( s <= S(HighestT) ) |
| | |--> not subranged |--> NONE |
| </code> |
| <code class="literal"> |
| int_to_float |--> NONE |
| </code> |
| <code class="literal"> |
| float_to_int |--> round_to_zero |--> ( s > S(LowestT)-S(1) ) && ( s < S(HighestT)+S(1) ) |
| |--> round_to_even_nearest |--> ( s >= S(LowestT)-S(0.5) ) && ( s < S(HighestT)+S(0.5) ) |
| |--> round_to_infinity |--> ( s > S(LowestT)-S(1) ) && ( s <= S(HighestT) ) |
| |--> round_to_neg_infinity |--> ( s >= S(LowestT) ) && ( s < S(HighestT)+S(1) ) |
| </code> |
| <code class="literal"> |
| float_to_float |--> subranged |--> ( s >= S(LowestT) ) && ( s <= S(HighestT) ) |
| |--> not subranged |--> NONE |
| </code> |
| </pre> |
| </div> |
| <div class="section" title="Examples"> |
| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="boost_numericconversion.converter___function_object.examples"></a><a class="link" href="converter___function_object.html#boost_numericconversion.converter___function_object.examples" title="Examples">Examples</a> |
| </h3></div></div></div> |
| <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">cassert</span><span class="special">></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">numeric</span><span class="special">/</span><span class="identifier">conversion</span><span class="special">/</span><span class="identifier">converter</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| |
| <span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> <span class="special">{</span> |
| |
| <span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">converter</span><span class="special"><</span><span class="keyword">int</span><span class="special">,</span><span class="keyword">double</span><span class="special">></span> <span class="identifier">Double2Int</span> <span class="special">;</span> |
| |
| <span class="keyword">int</span> <span class="identifier">x</span> <span class="special">=</span> <span class="identifier">Double2Int</span><span class="special">::</span><span class="identifier">convert</span><span class="special">(</span><span class="number">2.0</span><span class="special">);</span> |
| <span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">x</span> <span class="special">==</span> <span class="number">2</span> <span class="special">);</span> |
| |
| <span class="keyword">int</span> <span class="identifier">y</span> <span class="special">=</span> <span class="identifier">Double2Int</span><span class="special">()(</span><span class="number">3.14</span><span class="special">);</span> <span class="comment">// As a function object. |
| </span> <span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">y</span> <span class="special">==</span> <span class="number">3</span> <span class="special">)</span> <span class="special">;</span> <span class="comment">// The default rounding is trunc. |
| </span> |
| <span class="keyword">try</span> |
| <span class="special">{</span> |
| <span class="keyword">double</span> <span class="identifier">m</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">bounds</span><span class="special"><</span><span class="keyword">double</span><span class="special">>::</span><span class="identifier">highest</span><span class="special">();</span> |
| <span class="keyword">int</span> <span class="identifier">z</span> <span class="special">=</span> <span class="identifier">Double2Int</span><span class="special">::</span><span class="identifier">convert</span><span class="special">(</span><span class="identifier">m</span><span class="special">);</span> <span class="comment">// By default throws positive_overflow() |
| </span> <span class="special">}</span> |
| <span class="keyword">catch</span> <span class="special">(</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">positive_overflow</span> <span class="keyword">const</span><span class="special">&</span> <span class="special">)</span> |
| <span class="special">{</span> |
| <span class="special">}</span> |
| |
| <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> |
| <span class="special">}</span> |
| </pre> |
| </div> |
| </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 © 2004 -2007 Fernando Luis Cacciola Carballal<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> |
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