<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Standard Integer Types</title> <link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.75.2"> <link rel="home" href="../index.html" title="Boost.Integer"> <link rel="up" href="../index.html" title="Boost.Integer"> <link rel="prev" href="../index.html" title="Boost.Integer"> <link rel="next" href="traits.html" title="Integer Traits"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table cellpadding="2" width="100%"><tr> <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td> <td align="center"><a href="../../../../../index.html">Home</a></td> <td align="center"><a href="../../../../../libs/libraries.htm">Libraries</a></td> <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> <td align="center"><a href="../../../../../more/index.htm">More</a></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="../index.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="traits.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="section"> <div class="titlepage"><div><div><h2 class="title" style="clear: both"> <a name="boost_integer.cstdint"></a><a class="link" href="cstdint.html" title="Standard Integer Types"> Standard Integer Types</a> </h2></div></div></div> <div class="toc"><dl> <dt><span class="section"><a href="cstdint.html#boost_integer.cstdint.overview">Overview</a></span></dt> <dt><span class="section"><a href="cstdint.html#boost_integer.cstdint.rationale"> Rationale</a></span></dt> <dt><span class="section"><a href="cstdint.html#boost_integer.cstdint.ce"> <span class="emphasis"><em>Caveat emptor</em></span></a></span></dt> <dt><span class="section"><a href="cstdint.html#boost_integer.cstdint.exact_width_integer_types">Exact-width integer types</a></span></dt> <dt><span class="section"><a href="cstdint.html#boost_integer.cstdint.minimum_width_integer_types">Minimum-width integer types</a></span></dt> <dt><span class="section"><a href="cstdint.html#boost_integer.cstdint.fastest_minimum_width_integer_types">Fastest minimum-width integer types</a></span></dt> <dt><span class="section"><a href="cstdint.html#boost_integer.cstdint.greatest_width_integer_types">Greatest-width integer types</a></span></dt> <dt><span class="section"><a href="cstdint.html#boost_integer.cstdint.integer_constant_macros">Integer Constant Macros</a></span></dt> </dl></div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> <a name="boost_integer.cstdint.overview"></a><a class="link" href="cstdint.html#boost_integer.cstdint.overview" title="Overview">Overview</a> </h3></div></div></div> <p> The header <code class="literal"><a href="../../../../../boost/cstdint.hpp" target="_top"><boost/cstdint.hpp></a></code> provides the typedef's useful for writing portable code that requires certain integer widths. All typedef's are in namespace boost. </p> <p> The specifications for these types are based on the ISO/IEC 9899:1999 C Language standard header <stdint.h>. The 64-bit types required by the C standard are <span class="emphasis"><em>not required</em></span> in the boost header, and may not be supplied for all platforms/compilers, because <code class="literal">long long</code> is not [yet] included in the C++ standard. </p> <p> See <a href="../../../test/cstdint_test.cpp" target="_top">cstdint_test.cpp</a> for a test program. </p> </div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> <a name="boost_integer.cstdint.rationale"></a><a class="link" href="cstdint.html#boost_integer.cstdint.rationale" title="Rationale"> Rationale</a> </h3></div></div></div> <p> The organization of the Boost.Integer headers and classes is designed to take advantage of <stdint.h> types from the 1999 C standard without causing undefined behavior in terms of the 1998 C++ standard. The header <boost/cstdint.hpp> makes the standard integer types safely available in namespace <code class="literal">boost</code> without placing any names in namespace <code class="literal">std</code>. The intension is to complement rather than compete with the C++ Standard Library. Should some future C++ standard include <stdint.h> and <cstdint>, then <boost/cstdint.hpp> will continue to function, but will become redundant and may be safely deprecated. </p> <p> Because these are boost headers, their names conform to boost header naming conventions rather than C++ Standard Library header naming conventions. </p> </div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> <a name="boost_integer.cstdint.ce"></a><a class="link" href="cstdint.html#boost_integer.cstdint.ce" title="Caveat emptor"> <span class="emphasis"><em>Caveat emptor</em></span></a> </h3></div></div></div> <p> As an implementation artifact, certain C <limits.h> macro names may possibly be visible to users of <boost/cstdint.hpp>. Don't use these macros; they are not part of any Boost-specified interface. Use <code class="literal">boost::integer_traits<></code> or <code class="literal">std::numeric_limits<></code> instead. </p> <p> As another implementation artifact, certain C <stdint.h> typedef names may possibly be visible in the global namespace to users of <boost/cstdint.hpp>. Don't use these names, they are not part of any Boost-specified interface. Use the respective names in namespace <code class="literal">boost</code> instead. </p> </div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> <a name="boost_integer.cstdint.exact_width_integer_types"></a><a class="link" href="cstdint.html#boost_integer.cstdint.exact_width_integer_types" title="Exact-width integer types">Exact-width integer types</a> </h3></div></div></div> <p> The typedef <code class="literal">int#_t</code>, with # replaced by the width, designates a signed integer type of exactly # bits; for example <code class="literal">int8_t</code> denotes an 8-bit signed integer type. Similarly, the typedef <code class="literal">uint#_t</code> designates an unsigned integer type of exactly # bits. </p> <p> These types are optional. However, if a platform supports integer types with widths of 8, 16, 32, 64, or any combination thereof, then <boost/cstdint.hpp> does provide the corresponding typedefs. </p> <p> 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>. </p> </div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> <a name="boost_integer.cstdint.minimum_width_integer_types"></a><a class="link" href="cstdint.html#boost_integer.cstdint.minimum_width_integer_types" title="Minimum-width integer types">Minimum-width integer types</a> </h3></div></div></div> <p> The typedef <code class="literal">int_least#_t</code>, with # replaced by the width, designates a signed integer type with a width of at least # bits, such that no signed integer type with lesser size has at least the specified width. Thus, <code class="literal">int_least32_t</code> denotes the smallest signed integer type with a width of at least 32 bits. Similarly, the typedef name <code class="literal">uint_least#_t</code> designates an unsigned integer type with a width of at least # bits, such that no unsigned integer type with lesser size has at least the specified width. </p> <p> The following minimum-width integer types are provided for all platforms: </p> <div class="itemizedlist"><ul class="itemizedlist" type="disc"> <li class="listitem"> <code class="literal">int_least8_t</code> </li> <li class="listitem"> <code class="literal">int_least16_t</code> </li> <li class="listitem"> <code class="literal">int_least32_t</code> </li> <li class="listitem"> <code class="literal">uint_least8_t</code> </li> <li class="listitem"> <code class="literal">uint_least16_t</code> </li> <li class="listitem"> <code class="literal">uint_least32_t</code> </li> </ul></div> <p> The following types are available only if, after including <boost/cstdint.hpp>, the macro BOOST_NO_INT64_T is not defined: </p> <div class="itemizedlist"><ul class="itemizedlist" type="disc"> <li class="listitem"> <code class="literal">int_least64_t</code> </li> <li class="listitem"> <code class="literal">uint_least64_t</code> </li> </ul></div> <p> All other minimum-width integer types are optional. </p> </div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> <a name="boost_integer.cstdint.fastest_minimum_width_integer_types"></a><a class="link" href="cstdint.html#boost_integer.cstdint.fastest_minimum_width_integer_types" title="Fastest minimum-width integer types">Fastest minimum-width integer types</a> </h3></div></div></div> <p> The typedef <code class="literal">int_fast#_t</code>, with # replaced by the width, designates the fastest signed integer type with a width of at least # bits. Similarly, the typedef name <code class="literal">uint_fast#_t</code> designates the fastest unsigned integer type with a width of at least # bits. </p> <p> There is no guarantee that these types are fastest for all purposes. In any case, however, they satisfy the signedness and width requirements. </p> <p> The following fastest minimum-width integer types are provided for all platforms: </p> <div class="itemizedlist"><ul class="itemizedlist" type="disc"> <li class="listitem"> <code class="literal">int_fast8_t</code> </li> <li class="listitem"> <code class="literal">int_fast16_t</code> </li> <li class="listitem"> <code class="literal">int_fast32_t</code> </li> <li class="listitem"> <code class="literal">uint_fast8_t</code> </li> <li class="listitem"> <code class="literal">uint_fast16_t</code> </li> <li class="listitem"> <code class="literal">uint_fast32_t</code> </li> </ul></div> <p> The following types are available only if, after including <boost/cstdint.hpp>, the macro BOOST_NO_INT64_T is not defined: </p> <div class="itemizedlist"><ul class="itemizedlist" type="disc"> <li class="listitem"> <code class="literal">int_fast64_t</code> </li> <li class="listitem"> <code class="literal">uint_fast64_t</code> </li> </ul></div> <p> All other fastest minimum-width integer types are optional. </p> </div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> <a name="boost_integer.cstdint.greatest_width_integer_types"></a><a class="link" href="cstdint.html#boost_integer.cstdint.greatest_width_integer_types" title="Greatest-width integer types">Greatest-width integer types</a> </h3></div></div></div> <p> The typedef <code class="literal">intmax_t </code>designates a signed integer type capable of representing any value of any signed integer type. </p> <p> The typedef <code class="literal">uintmax_t</code> designates an unsigned integer type capable of representing any value of any unsigned integer type. </p> <p> These types are provided for all platforms. </p> </div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> <a name="boost_integer.cstdint.integer_constant_macros"></a><a class="link" href="cstdint.html#boost_integer.cstdint.integer_constant_macros" title="Integer Constant Macros">Integer Constant Macros</a> </h3></div></div></div> <p> The following macros are always defined after inclusion of this header, these allow integer constants of at least the specified width to be declared: INT8_C, UINT8_C, INT16_C, UINT16_C, INT32_C, UINT32_C, INTMAX_C, UINTMAX_C. </p> <p> The macros INT64_C and UINT64_C are also defined if the the macro BOOST_NO_INT64_T is not defined. </p> <p> The C99 macro __STDC_CONSTANT_MACROS is also defined as an artifact of the implementation. </p> <p> For example: </p> <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</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">></span> <span class="comment">// Here the constant 0x1FFFFFFFF has the correct suffix applied: </span><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> </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 © 2001 -2009 Beman Dawes, Daryle Walker, Gennaro Prota, John Maddock<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> <div class="spirit-nav"> <a accesskey="p" href="../index.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="traits.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html>