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  26 <div class="titlepage"><div><div><h2 class="title" style="clear: both">
  27 <a name="boost_config.cstdint"></a><a class="link" href="cstdint.html" title="Standard Integer Types">Standard Integer Types</a>
  28 </h2></div></div></div>
  29 <div class="toc"><dl>
  30 <dt><span class="section"><a href="cstdint.html#boost_config.cstdint.overview">Overview</a></span></dt>
  31 <dt><span class="section"><a href="cstdint.html#boost_config.cstdint.rationale">Rationale</a></span></dt>
  32 <dt><span class="section"><a href="cstdint.html#boost_config.cstdint.ce"><span class="emphasis"><em>Caveat emptor</em></span></a></span></dt>
  33 <dt><span class="section"><a href="cstdint.html#boost_config.cstdint.exact_width_integer_types">Exact-width
  34       integer types</a></span></dt>
  35 <dt><span class="section"><a href="cstdint.html#boost_config.cstdint.minimum_width_integer_types">Minimum-width
  36       integer types</a></span></dt>
  37 <dt><span class="section"><a href="cstdint.html#boost_config.cstdint.fastest_minimum_width_integer_types">Fastest
  38       minimum-width integer types</a></span></dt>
  39 <dt><span class="section"><a href="cstdint.html#boost_config.cstdint.greatest_width_integer_types">Greatest-width
  40       integer types</a></span></dt>
  41 <dt><span class="section"><a href="cstdint.html#boost_config.cstdint.integer_constant_macros">Integer
  42       Constant Macros</a></span></dt>
  43 </dl></div>
  44 <div class="section">
  45 <div class="titlepage"><div><div><h3 class="title">
  46 <a name="boost_config.cstdint.overview"></a><a class="link" href="cstdint.html#boost_config.cstdint.overview" title="Overview">Overview</a>
  47 </h3></div></div></div>
  48 <p>
  49         The header <code class="literal"><a href="../../../../../boost/cstdint.hpp" target="_top">&lt;boost/cstdint.hpp&gt;</a></code>
  50         provides the typedef's useful for writing portable code that requires certain
  51         integer widths. All typedef's are in namespace boost.
  52       </p>
  53 <p>
  54         The specifications for these types are based on the ISO/IEC 9899:1999 C Language
  55         standard header &lt;stdint.h&gt;. The 64-bit types required by the C standard
  56         are <span class="emphasis"><em>not required</em></span> in the boost header, and may not be
  57         supplied for all platforms/compilers, because <code class="literal">long long</code>
  58         is not [yet] included in the C++ standard.
  59       </p>
  60 <p>
  61         See <a href="../../../test/cstdint_test.cpp" target="_top">cstdint_test.cpp</a> for
  62         a test program.
  63       </p>
  64 </div>
  65 <div class="section">
  66 <div class="titlepage"><div><div><h3 class="title">
  67 <a name="boost_config.cstdint.rationale"></a><a class="link" href="cstdint.html#boost_config.cstdint.rationale" title="Rationale">Rationale</a>
  68 </h3></div></div></div>
  69 <p>
  70         The organization of the Boost.Integer headers and classes is designed to
  71         take advantage of &lt;stdint.h&gt; types from the 1999 C standard without
  72         causing undefined behavior in terms of the 1998 C++ standard. The header
  73         &lt;boost/cstdint.hpp&gt; makes the standard integer types safely available
  74         in namespace <code class="literal">boost</code> without placing any names in namespace
  75         <code class="literal">std</code>. The intension is to complement rather than compete
  76         with the C++ Standard Library. Should some future C++ standard include &lt;stdint.h&gt;
  77         and &lt;cstdint&gt;, then &lt;boost/cstdint.hpp&gt; will continue to function,
  78         but will become redundant and may be safely deprecated.
  79       </p>
  80 <p>
  81         Because these are boost headers, their names conform to boost header naming
  82         conventions rather than C++ Standard Library header naming conventions.
  83       </p>
  84 </div>
  85 <div class="section">
  86 <div class="titlepage"><div><div><h3 class="title">
  87 <a name="boost_config.cstdint.ce"></a><a class="link" href="cstdint.html#boost_config.cstdint.ce" title="Caveat emptor"><span class="emphasis"><em>Caveat emptor</em></span></a>
  88 </h3></div></div></div>
  89 <p>
  90         As an implementation artifact, certain C &lt;limits.h&gt; macro names may
  91         possibly be visible to users of &lt;boost/cstdint.hpp&gt;. Don't use these
  92         macros; they are not part of any Boost-specified interface. Use <code class="literal">boost::integer_traits&lt;&gt;</code>
  93         or <code class="literal">std::numeric_limits&lt;&gt;</code> instead.
  94       </p>
  95 <p>
  96         As another implementation artifact, certain C &lt;stdint.h&gt; typedef names
  97         may possibly be visible in the global namespace to users of &lt;boost/cstdint.hpp&gt;.
  98         Don't use these names, they are not part of any Boost-specified interface.
  99         Use the respective names in namespace <code class="literal">boost</code> instead.
 100       </p>
 101 </div>
 102 <div class="section">
 103 <div class="titlepage"><div><div><h3 class="title">
 104 <a name="boost_config.cstdint.exact_width_integer_types"></a><a class="link" href="cstdint.html#boost_config.cstdint.exact_width_integer_types" title="Exact-width integer types">Exact-width
 105       integer types</a>
 106 </h3></div></div></div>
 107 <p>
 108         The typedef <code class="literal">int#_t</code>, with # replaced by the width, designates
 109         a signed integer type of exactly # bits; for example <code class="literal">int8_t</code>
 110         denotes an 8-bit signed integer type. Similarly, the typedef <code class="literal">uint#_t</code>
 111         designates an unsigned integer type of exactly # bits.
 112       </p>
 113 <p>
 114         These types are optional. However, if a platform supports integer types with
 115         widths of 8, 16, 32, 64, or any combination thereof, then &lt;boost/cstdint.hpp&gt;
 116         does provide the corresponding typedefs.
 117       </p>
 118 <p>
 119         The absence of int64_t and uint64_t is indicated by the macro <code class="computeroutput"><span class="identifier">BOOST_NO_INT64_T</span></code>.
 120       </p>
 121 </div>
 122 <div class="section">
 123 <div class="titlepage"><div><div><h3 class="title">
 124 <a name="boost_config.cstdint.minimum_width_integer_types"></a><a class="link" href="cstdint.html#boost_config.cstdint.minimum_width_integer_types" title="Minimum-width integer types">Minimum-width
 125       integer types</a>
 126 </h3></div></div></div>
 127 <p>
 128         The typedef <code class="literal">int_least#_t</code>, with # replaced by the width,
 129         designates a signed integer type with a width of at least # bits, such that
 130         no signed integer type with lesser size has at least the specified width.
 131         Thus, <code class="literal">int_least32_t</code> denotes the smallest signed integer
 132         type with a width of at least 32 bits. Similarly, the typedef name <code class="literal">uint_least#_t</code>
 133         designates an unsigned integer type with a width of at least # bits, such
 134         that no unsigned integer type with lesser size has at least the specified
 135         width.
 136       </p>
 137 <p>
 138         The following minimum-width integer types are provided for all platforms:
 139       </p>
 140 <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
 141 <li class="listitem">
 142             <code class="literal">int_least8_t</code>
 143           </li>
 144 <li class="listitem">
 145             <code class="literal">int_least16_t</code>
 146           </li>
 147 <li class="listitem">
 148             <code class="literal">int_least32_t</code>
 149           </li>
 150 <li class="listitem">
 151             <code class="literal">uint_least8_t</code>
 152           </li>
 153 <li class="listitem">
 154             <code class="literal">uint_least16_t</code>
 155           </li>
 156 <li class="listitem">
 157             <code class="literal">uint_least32_t</code>
 158           </li>
 159 </ul></div>
 160 <p>
 161         The following types are available only if, after including &lt;boost/cstdint.hpp&gt;,
 162         the macro BOOST_NO_INT64_T is not defined:
 163       </p>
 164 <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
 165 <li class="listitem">
 166             <code class="literal">int_least64_t</code>
 167           </li>
 168 <li class="listitem">
 169             <code class="literal">uint_least64_t</code>
 170           </li>
 171 </ul></div>
 172 <p>
 173         All other minimum-width integer types are optional.
 174       </p>
 175 </div>
 176 <div class="section">
 177 <div class="titlepage"><div><div><h3 class="title">
 178 <a name="boost_config.cstdint.fastest_minimum_width_integer_types"></a><a class="link" href="cstdint.html#boost_config.cstdint.fastest_minimum_width_integer_types" title="Fastest minimum-width integer types">Fastest
 179       minimum-width integer types</a>
 180 </h3></div></div></div>
 181 <p>
 182         The typedef <code class="literal">int_fast#_t</code>, with # replaced by the width,
 183         designates the fastest signed integer type with a width of at least # bits.
 184         Similarly, the typedef name <code class="literal">uint_fast#_t</code> designates the
 185         fastest unsigned integer type with a width of at least # bits.
 186       </p>
 187 <p>
 188         There is no guarantee that these types are fastest for all purposes. In any
 189         case, however, they satisfy the signedness and width requirements.
 190       </p>
 191 <p>
 192         The following fastest minimum-width integer types are provided for all platforms:
 193       </p>
 194 <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
 195 <li class="listitem">
 196             <code class="literal">int_fast8_t</code>
 197           </li>
 198 <li class="listitem">
 199             <code class="literal">int_fast16_t</code>
 200           </li>
 201 <li class="listitem">
 202             <code class="literal">int_fast32_t</code>
 203           </li>
 204 <li class="listitem">
 205             <code class="literal">uint_fast8_t</code>
 206           </li>
 207 <li class="listitem">
 208             <code class="literal">uint_fast16_t</code>
 209           </li>
 210 <li class="listitem">
 211             <code class="literal">uint_fast32_t</code>
 212           </li>
 213 </ul></div>
 214 <p>
 215         The following types are available only if, after including &lt;boost/cstdint.hpp&gt;,
 216         the macro BOOST_NO_INT64_T is not defined:
 217       </p>
 218 <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
 219 <li class="listitem">
 220             <code class="literal">int_fast64_t</code>
 221           </li>
 222 <li class="listitem">
 223             <code class="literal">uint_fast64_t</code>
 224           </li>
 225 </ul></div>
 226 <p>
 227         All other fastest minimum-width integer types are optional.
 228       </p>
 229 </div>
 230 <div class="section">
 231 <div class="titlepage"><div><div><h3 class="title">
 232 <a name="boost_config.cstdint.greatest_width_integer_types"></a><a class="link" href="cstdint.html#boost_config.cstdint.greatest_width_integer_types" title="Greatest-width integer types">Greatest-width
 233       integer types</a>
 234 </h3></div></div></div>
 235 <p>
 236         The typedef <code class="literal">intmax_t </code>designates a signed integer type
 237         capable of representing any value of any signed integer type.
 238       </p>
 239 <p>
 240         The typedef <code class="literal">uintmax_t</code> designates an unsigned integer type
 241         capable of representing any value of any unsigned integer type.
 242       </p>
 243 <p>
 244         These types are provided for all platforms.
 245       </p>
 246 </div>
 247 <div class="section">
 248 <div class="titlepage"><div><div><h3 class="title">
 249 <a name="boost_config.cstdint.integer_constant_macros"></a><a class="link" href="cstdint.html#boost_config.cstdint.integer_constant_macros" title="Integer Constant Macros">Integer
 250       Constant Macros</a>
 251 </h3></div></div></div>
 252 <p>
 253         The following macros are always defined after inclusion of this header, these
 254         allow integer constants of at least the specified width to be declared: INT8_C,
 255         UINT8_C, INT16_C, UINT16_C, INT32_C, UINT32_C, INTMAX_C, UINTMAX_C.
 256       </p>
 257 <p>
 258         The macros INT64_C and UINT64_C are also defined if the the macro BOOST_NO_INT64_T
 259         is not defined.
 260       </p>
 261 <p>
 262         The C99 macro __STDC_CONSTANT_MACROS is also defined as an artifact of the
 263         implementation.
 264       </p>
 265 <p>
 266         For example:
 267       </p>
 268 <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">cstdint</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
 269
 270 <span class="comment">// Here the constant 0x1FFFFFFFF has the correct suffix applied:</span>
 271 <span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">uint64_t</span> <span class="identifier">c</span> <span class="special">=</span> <span class="identifier">INT64_C</span><span class="special">(</span><span class="number">0</span><span class="identifier">x1FFFFFFFF</span><span class="special">);</span>
 272 </pre>
 273 </div>
 274 </div>
 275 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 276 <td align="left"></td>
 277 <td align="right"><div class="copyright-footer">Copyright &#169; 2001-2007 Beman Dawes, Vesa Karvonen, John
 278       Maddock<p>
 279         Distributed under the Boost Software License, Version 1.0. (See accompanying
 280         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>)
 281       </p>
 282 </div></td>
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