1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Chapter 1. Boost.NumericConversion</title> 5<link rel="stylesheet" href="boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="index.html" title="Chapter 1. Boost.NumericConversion"> 8<link rel="next" href="boost_numericconversion/definitions.html" title="Definitions"> 9</head> 10<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 11<table cellpadding="2" width="100%"><tr> 12<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td> 13<td align="center"><a href="../../../../../index.html">Home</a></td> 14<td align="center"><a href="../../../../../libs/libraries.htm">Libraries</a></td> 15<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 16<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 17<td align="center"><a href="../../../../../more/index.htm">More</a></td> 18</tr></table> 19<hr> 20<div class="spirit-nav"><a accesskey="n" href="boost_numericconversion/definitions.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a></div> 21<div class="chapter"> 22<div class="titlepage"><div> 23<div><h2 class="title"> 24<a name="numeric_conversion"></a>Chapter 1. Boost.NumericConversion</h2></div> 25<div><div class="author"><h3 class="author"> 26<span class="firstname">Fernando Luis</span> <span class="surname">Cacciola Carballal</span> 27</h3></div></div> 28<div><p class="copyright">Copyright © 2004-2007 Fernando 29 Luis Cacciola Carballal</p></div> 30<div><div class="legalnotice"> 31<a name="numeric_conversion.legal"></a><p> 32 Distributed under the Boost Software License, Version 1.0. (See accompanying 33 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>) 34 </p> 35</div></div> 36</div></div> 37<div class="toc"> 38<p><b>Table of Contents</b></p> 39<dl class="toc"> 40<dt><span class="section"><a href="index.html#numeric_conversion.overview">Overview</a></span></dt> 41<dt><span class="section"><a href="boost_numericconversion/definitions.html">Definitions</a></span></dt> 42<dd><dl> 43<dt><span class="section"><a href="boost_numericconversion/definitions.html#boost_numericconversion.definitions.introduction">Introduction</a></span></dt> 44<dt><span class="section"><a href="boost_numericconversion/definitions.html#boost_numericconversion.definitions.types_and_values">Types 45 and Values</a></span></dt> 46<dt><span class="section"><a href="boost_numericconversion/definitions.html#boost_numericconversion.definitions.c___arithmetic_types">C++ 47 Arithmetic Types</a></span></dt> 48<dt><span class="section"><a href="boost_numericconversion/definitions.html#boost_numericconversion.definitions.numeric_types">Numeric 49 Types</a></span></dt> 50<dt><span class="section"><a href="boost_numericconversion/definitions.html#boost_numericconversion.definitions.range_and_precision">Range 51 and Precision</a></span></dt> 52<dt><span class="section"><a href="boost_numericconversion/definitions.html#boost_numericconversion.definitions.exact__correctly_rounded_and_out_of_range_representations">Exact, 53 Correctly Rounded and Out-Of-Range Representations</a></span></dt> 54<dt><span class="section"><a href="boost_numericconversion/definitions.html#boost_numericconversion.definitions.standard__numeric__conversions">Standard 55 (numeric) Conversions</a></span></dt> 56<dt><span class="section"><a href="boost_numericconversion/definitions.html#boost_numericconversion.definitions.subranged_conversion_direction__subtype_and_supertype">Subranged 57 Conversion Direction, Subtype and Supertype</a></span></dt> 58</dl></dd> 59<dt><span class="section"><a href="boost_numericconversion/converter___function_object.html">converter<> 60 function object</a></span></dt> 61<dd><dl> 62<dt><span class="section"><a href="boost_numericconversion/converter___function_object.html#boost_numericconversion.converter___function_object.synopsis">Synopsis</a></span></dt> 63<dt><span class="section"><a href="boost_numericconversion/converter___function_object.html#boost_numericconversion.converter___function_object.template_parameters">Template 64 parameters</a></span></dt> 65<dt><span class="section"><a href="boost_numericconversion/converter___function_object.html#boost_numericconversion.converter___function_object.member_functions">Member 66 functions</a></span></dt> 67<dt><span class="section"><a href="boost_numericconversion/converter___function_object.html#boost_numericconversion.converter___function_object.range_checking_logic">Range 68 Checking Logic</a></span></dt> 69<dt><span class="section"><a href="boost_numericconversion/converter___function_object.html#boost_numericconversion.converter___function_object.examples">Examples</a></span></dt> 70</dl></dd> 71<dt><span class="section"><a href="boost_numericconversion/type_requirements_and_user_defined_types_support.html">Type 72 Requirements and User-defined-types support</a></span></dt> 73<dd><dl> 74<dt><span class="section"><a href="boost_numericconversion/type_requirements_and_user_defined_types_support.html#boost_numericconversion.type_requirements_and_user_defined_types_support.type_requirements">Type 75 Requirements</a></span></dt> 76<dt><span class="section"><a href="boost_numericconversion/type_requirements_and_user_defined_types_support.html#boost_numericconversion.type_requirements_and_user_defined_types_support.udt_s_special_semantics">UDT's 77 special semantics</a></span></dt> 78<dt><span class="section"><a href="boost_numericconversion/type_requirements_and_user_defined_types_support.html#boost_numericconversion.type_requirements_and_user_defined_types_support.special_policies">Special 79 Policies</a></span></dt> 80<dt><span class="section"><a href="boost_numericconversion/type_requirements_and_user_defined_types_support.html#boost_numericconversion.type_requirements_and_user_defined_types_support.udts_with_numeric_cast">UDTs 81 with numeric_cast</a></span></dt> 82</dl></dd> 83<dt><span class="section"><a href="boost_numericconversion/bounds___traits_class.html">bounds<> 84 traits class</a></span></dt> 85<dd><dl> 86<dt><span class="section"><a href="boost_numericconversion/bounds___traits_class.html#boost_numericconversion.bounds___traits_class.introduction">Introduction</a></span></dt> 87<dt><span class="section"><a href="boost_numericconversion/bounds___traits_class.html#boost_numericconversion.bounds___traits_class.traits_class_bounds_n_">traits 88 class bounds<N></a></span></dt> 89<dt><span class="section"><a href="boost_numericconversion/bounds___traits_class.html#boost_numericconversion.bounds___traits_class.examples">Examples</a></span></dt> 90</dl></dd> 91<dt><span class="section"><a href="boost_numericconversion/conversion_traits___traits_class.html">conversion_traits<> 92 traits class</a></span></dt> 93<dd><dl> 94<dt><span class="section"><a href="boost_numericconversion/conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types">Types</a></span></dt> 95<dt><span class="section"><a href="boost_numericconversion/conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.examples">Examples</a></span></dt> 96</dl></dd> 97<dt><span class="section"><a href="boost_numericconversion/numeric_converter_policy_classes.html">Numeric 98 Converter Policy Classes</a></span></dt> 99<dd><dl> 100<dt><span class="section"><a href="boost_numericconversion/numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.enum_range_check_result">enum 101 range_check_result</a></span></dt> 102<dt><span class="section"><a href="boost_numericconversion/numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_overflowhandler">Policy 103 OverflowHandler</a></span></dt> 104<dt><span class="section"><a href="boost_numericconversion/numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_float2introunder">Policy 105 Float2IntRounder</a></span></dt> 106<dt><span class="section"><a href="boost_numericconversion/numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_rawconverter">Policy 107 RawConverter</a></span></dt> 108<dt><span class="section"><a href="boost_numericconversion/numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_userrangechecker">Policy 109 UserRangeChecker</a></span></dt> 110</dl></dd> 111<dt><span class="section"><a href="boost_numericconversion/improved_numeric_cast__.html">Improved 112 numeric_cast<></a></span></dt> 113<dd><dl> 114<dt><span class="section"><a href="boost_numericconversion/improved_numeric_cast__.html#boost_numericconversion.improved_numeric_cast__.introduction">Introduction</a></span></dt> 115<dt><span class="section"><a href="boost_numericconversion/improved_numeric_cast__.html#boost_numericconversion.improved_numeric_cast__.numeric_cast">numeric_cast</a></span></dt> 116<dt><span class="section"><a href="boost_numericconversion/improved_numeric_cast__.html#boost_numericconversion.improved_numeric_cast__.numeric_cast_traits">numeric_cast_traits</a></span></dt> 117<dt><span class="section"><a href="boost_numericconversion/improved_numeric_cast__.html#boost_numericconversion.improved_numeric_cast__.examples">Examples</a></span></dt> 118</dl></dd> 119<dt><span class="section"><a href="numeric_conversion/history_and_acknowledgments.html">History 120 and Acknowledgments</a></span></dt> 121<dt><span class="section"><a href="numeric_conversion/bibliography.html">Bibliography</a></span></dt> 122</dl> 123</div> 124<div class="section"> 125<div class="titlepage"><div><div><h2 class="title" style="clear: both"> 126<a name="numeric_conversion.overview"></a><a class="link" href="index.html#numeric_conversion.overview" title="Overview">Overview</a> 127</h2></div></div></div> 128<p> 129 The Boost Numeric Conversion library is a collection of tools to describe and 130 perform conversions between values of different <a class="link" href="boost_numericconversion/definitions.html#boost_numericconversion.definitions.numeric_types" title="Numeric Types">numeric 131 types</a>. 132 </p> 133<p> 134 The library includes a special alternative for a subset of <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">numeric_limits</span><span class="special"><></span></code>, the <a class="link" href="boost_numericconversion/bounds___traits_class.html" title="bounds<> traits class">bounds<></a> 135 traits class, which provides a consistent way to obtain the <a class="link" href="boost_numericconversion/definitions.html#boost_numericconversion.definitions.range_and_precision" title="Range and Precision">boundary</a> 136 values for the <a class="link" href="boost_numericconversion/definitions.html#boost_numericconversion.definitions.range_and_precision" title="Range and Precision">range</a> 137 of a numeric type. 138 </p> 139<p> 140 It also includes a set of <a class="link" href="boost_numericconversion/conversion_traits___traits_class.html" title="conversion_traits<> traits class">trait 141 classes</a> which describes the compile-time properties of a conversion 142 from a source to a target numeric type. Both <a class="link" href="boost_numericconversion/definitions.html#boost_numericconversion.definitions.c___arithmetic_types" title="C++ Arithmetic Types">arithmetic</a> 143 and <a class="link" href="boost_numericconversion/definitions.html#boost_numericconversion.definitions.numeric_types" title="Numeric Types">user-defined 144 numeric types</a> can be used. 145 </p> 146<p> 147 A policy-based <a class="link" href="boost_numericconversion/converter___function_object.html" title="converter<> function object">converter</a> 148 object which uses <code class="computeroutput"><span class="identifier">conversion_traits</span></code> 149 to select an optimized implementation is supplied. Such implementation uses 150 an optimal range checking code suitable for the source/target combination. 151 </p> 152<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 153<li class="listitem"> 154 The converter's out-of-range behavior can be customized via an <a class="link" href="boost_numericconversion/numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_overflowhandler" title="Policy OverflowHandler">OverflowHandler</a> 155 policy. 156 </li> 157<li class="listitem"> 158 For floating-point to integral conversions, the rounding mode can be selected 159 via the <a class="link" href="boost_numericconversion/numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_float2introunder" title="Policy Float2IntRounder">Float2IntRounder</a> 160 policy. 161 </li> 162<li class="listitem"> 163 A custom low-level conversion routine (for UDTs for instance) can be passed 164 via a <a class="link" href="boost_numericconversion/numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_rawconverter" title="Policy RawConverter">RawConverter</a> 165 policy. 166 </li> 167<li class="listitem"> 168 The optimized automatic range-checking logic can be overridden via a <a class="link" href="boost_numericconversion/numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_userrangechecker" title="Policy UserRangeChecker">UserRangeChecker</a> 169 policy. 170 </li> 171</ul></div> 172</div> 173</div> 174<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 175<td align="left"><p><small>Last revised: August 11, 2020 at 14:59:49 GMT</small></p></td> 176<td align="right"><div class="copyright-footer"></div></td> 177</tr></table> 178<hr> 179<div class="spirit-nav"><a accesskey="n" href="boost_numericconversion/definitions.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a></div> 180</body> 181</html> 182
