mirror of
https://github.com/boostorg/integer.git
synced 2025-06-25 20:11:41 +02:00
Compare commits
1 Commits
boost-1.16
...
svn-branch
| Author | SHA1 | Date | |
|---|---|---|---|
| 0101ecf6ef |
79
cstdint.htm
Normal file
79
cstdint.htm
Normal file
@ -0,0 +1,79 @@
|
||||
<html>
|
||||
|
||||
<head>
|
||||
<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
|
||||
<meta name="GENERATOR" content="Microsoft FrontPage 4.0">
|
||||
<meta name="ProgId" content="FrontPage.Editor.Document">
|
||||
<title>Header boost/cstdint.hpp</title>
|
||||
</head>
|
||||
|
||||
<body bgcolor="#FFFFFF" text="#000000">
|
||||
|
||||
<h1><img src="../../c++boost.gif" alt="c++boost.gif (8819 bytes)" align="center" width="277" height="86">Header
|
||||
boost/cstdint.hpp </h1>
|
||||
<p>The header <code><a href="../../boost/cstdint.hpp"><boost/cstdint.hpp></a></code>
|
||||
places the contents of the header <code><a href="../../boost/stdint.h"><boost/stdint.h></a></code>
|
||||
in namespace boost. That header consists entirely of typedef's useful for
|
||||
writing portable code that requires certain integer widths.</p>
|
||||
<p>The specifications are based on the ISO/IEC 9899:1999 C Language standard
|
||||
header stdint.h. The 64-bit types required by the C standard are not
|
||||
required in the boost header, and may not be supplied in all implementations,
|
||||
because <code>long long</code> is not [yet] included in the C++ standard.</p>
|
||||
<p>See <a href="cstdint_test.cpp">cstdint_test.cpp</a> for a test program.</p>
|
||||
<h2>Exact-width integer types</h2>
|
||||
<p>The typedef <code>int#_t</code>, with # replaced by the width, designates a
|
||||
signed integer type of exactly # bits; <code>int8_t</code> denotes an 8-bit
|
||||
signed integer type. Similarly, the typedef <code>uint#_t</code>
|
||||
designates and unsigned integer type of exactly # bits.</p>
|
||||
<p>These types are optional. However, if an implementation provides integer
|
||||
types with widths of 8, 16, 32, or 64 bits, it shall define the corresponding
|
||||
typedef names.</p>
|
||||
<h2>Minimum-width integer types</h2>
|
||||
<p>The typedef <code>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>int_least32_t</code>
|
||||
denotes a signed integer type with a width of at least 32 bits. Similarly, the
|
||||
typedef name <code>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>Required minimum-width integer types:</p>
|
||||
<ul>
|
||||
<li><code>int_least8_t</code></li>
|
||||
<li><code>int_least16_t</code></li>
|
||||
<li><code>int_least32_t</code></li>
|
||||
<li><code>uint_least8_t</code></li>
|
||||
<li><code>uint_least16_t</code></li>
|
||||
<li><code>uint_least32_t</code></li>
|
||||
</ul>
|
||||
<p>All other minimum-width integer types are optional.</p>
|
||||
<h2>Fastest minimum-width integer types</h2>
|
||||
<p>The typedef <code>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>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>Required fastest minimum-width integer types:</p>
|
||||
<ul>
|
||||
<li><code>int_fast8_t</code></li>
|
||||
<li><code>int_fast16_t</code></li>
|
||||
<li><code>int_fast32_t</code></li>
|
||||
<li><code>uint_fast8_t</code></li>
|
||||
<li><code>uint_fast16_t</code></li>
|
||||
<li><code>uint_fast32_t</code></li>
|
||||
</ul>
|
||||
<p>All other fastest minimum-width integer types are optional.</p>
|
||||
<h2>Greatest-width integer types</h2>
|
||||
<p>The typedef <code>intmax_t </code>designates a signed integer type capable of
|
||||
representing any value of any signed integer type.</p>
|
||||
<p>The typedef <code>uintmax_t</code> designates an unsigned integer type
|
||||
capable of representing any value of any unsigned integer type.</p>
|
||||
<p>These types are required.</p>
|
||||
<hr>
|
||||
<p>Revised <!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %b %Y" startspan -->29 Jun 2000<!--webbot bot="Timestamp" endspan i-checksum="15060" -->
|
||||
</p>
|
||||
<p> </p>
|
||||
|
||||
</body>
|
||||
|
||||
</html>
|
||||
@ -9,6 +9,7 @@
|
||||
// See http://www.boost.org for most recent version including documentation.
|
||||
|
||||
// Revision History
|
||||
// 30 Jul 00 Add typename syntax fix (Jens Maurer)
|
||||
// 28 Aug 99 Initial version
|
||||
|
||||
#ifndef BOOST_INTEGER_HPP
|
||||
@ -45,7 +46,7 @@ namespace boost
|
||||
template< int Bits > // bits (including sign) required
|
||||
struct int_t
|
||||
{
|
||||
typedef int_least_helper
|
||||
typedef typename int_least_helper
|
||||
<
|
||||
(Bits-1 <= std::numeric_limits<long>::digits) +
|
||||
(Bits-1 <= std::numeric_limits<int>::digits) +
|
||||
@ -59,7 +60,7 @@ namespace boost
|
||||
template< int Bits > // bits required
|
||||
struct uint_t
|
||||
{
|
||||
typedef int_least_helper
|
||||
typedef typename int_least_helper
|
||||
<
|
||||
5 +
|
||||
(Bits <= std::numeric_limits<unsigned long>::digits) +
|
||||
@ -77,3 +78,4 @@ namespace boost
|
||||
} // namespace boost
|
||||
|
||||
#endif // BOOST_INTEGER_HPP
|
||||
|
||||
|
||||
98
index.htm
Normal file
98
index.htm
Normal file
@ -0,0 +1,98 @@
|
||||
<html>
|
||||
|
||||
<head>
|
||||
<meta http-equiv="Content-Language" content="en-us">
|
||||
<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
|
||||
<meta name="GENERATOR" content="Microsoft FrontPage 4.0">
|
||||
<meta name="ProgId" content="FrontPage.Editor.Document">
|
||||
<title>Boost Integer Library</title>
|
||||
</head>
|
||||
|
||||
<body bgcolor="#FFFFFF" text="#000000">
|
||||
|
||||
<table border="1" bgcolor="#007F7F" cellpadding="2">
|
||||
<tr>
|
||||
<td bgcolor="#FFFFFF"><img src="../../c++boost.gif" alt="c++boost.gif (8819 bytes)" width="277" height="86"></td>
|
||||
<td><a href="../../index.htm"><font face="Arial" color="#FFFFFF"><big>Home </big></font></a></td>
|
||||
<td><a href="../../libraries.htm"><font face="Arial" color="#FFFFFF"><big>Libraries </big></font></a></td>
|
||||
<td><a href="../../people.htm"><font face="Arial" color="#FFFFFF"><big>People </big></font></a></td>
|
||||
<td><a href="../../more/faq.htm"><font face="Arial" color="#FFFFFF"><big>FAQ </big></font></a></td>
|
||||
<td><a href="../../more/index.htm"><font face="Arial" color="#FFFFFF"><big>More </big></font></a></td>
|
||||
</tr>
|
||||
</table>
|
||||
|
||||
<h1>Boost Integer Library</h1>
|
||||
|
||||
<table border="1" cellpadding="5">
|
||||
<tr>
|
||||
<td align="center"><b><i>Header / Docs</i></b></td>
|
||||
<td align="center"><b><i>Contents</i></b></td>
|
||||
<td align="center"><b><i>Use</i></b></td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td align="center"><code><a href="../../boost/cstdint.hpp"><boost/cstdint.hpp><br>
|
||||
</a></code><a href="cstdint.htm"><br>
|
||||
documentation</a>
|
||||
</td>
|
||||
<td valign="top">Contents of <code><boost/stdint.h></code> wrapped in namespace boost.</td>
|
||||
<td valign="top">Supplies typedefs for standard integer types such as <code> int32_t</code> or <code>uint_least16_t</code>.
|
||||
Use in preference to <<code>stdint.h></code> or<code> <boost/stdint.h></code>
|
||||
because the names are safely placed in the boost namespace.</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td align="center"><code><a href="../../boost/stdint.h"><boost/stdint.h></a></code></td>
|
||||
<td valign="top">Typedefs as defined in the C99 standard header <<code>stdint.h></code>.
|
||||
This implementation #includes the compiler
|
||||
supplied <<code>stdint.h></code>, if present.</td>
|
||||
<td valign="top"> Supplied
|
||||
for use in the implementation of <boost/cstdint.hpp> and to ease transition to the C99 standard.
|
||||
Other uses are not recommended because this header places its names in the global namespace. </td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td align="center"><code><a href="../../boost/integer_traits.hpp"><boost/integer_traits.hpp></a></code><br>
|
||||
<br>
|
||||
<a href="integer_traits.html">documentation</a>
|
||||
</td>
|
||||
<td valign="top">Template class <code>boost::integer_traits</code>, derived from <code>std::numeric_limits</code>.
|
||||
Adds <code>const_min</code> and <code>const_max</code> members.</td>
|
||||
<td valign="top">Use to obtain the characteristics of a known integer type.</td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td align="center"><code><a href="../../boost/integer.hpp"><boost/integer.hpp></a><br>
|
||||
<br>
|
||||
</code><a href="integer.htm">documentation</a></td>
|
||||
<td valign="top">Templates for integer type selection based on properties such as
|
||||
maximum value or number of bits.</td>
|
||||
<td valign="top">Use to select the type an integer when some property such as maximum value or number of bits is known.
|
||||
Useful for generic programming. </td>
|
||||
</tr>
|
||||
</table>
|
||||
|
||||
<h2>Rationale</h2>
|
||||
<p>The organization of boost integer headers and classes is designed to take
|
||||
advantage of <code><stdint.h></code> types from in the 1999 C standard
|
||||
without resorting to undefined behavior in terms of
|
||||
the 1998 C++ standard. The header <code><boost/cstdint.hpp></code>
|
||||
makes the standard integer types safely available in namespace boost without placing any names in the
|
||||
global namespace or namespace std. As always, the intension is to complement rather than
|
||||
compete with the C++ Standard Library. Should some future C++ standard
|
||||
include <code><stdint.h></code> and <code><cstdint></code>, then <code><boost/stdint.h></code> and <code><boost/cstdint.hpp></code>
|
||||
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. An
|
||||
exception is <code><boost/stdint.h> </code>which uses a <b> .h</b> extension to indicate its C rather than C++ heritage.</p>
|
||||
<h2>Caveat emptor</h2>
|
||||
<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 boost:: integer_traits<> or std::numeric_limits<> instead.</p>
|
||||
|
||||
<hr>
|
||||
|
||||
<p>Revised: <!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%d %b %Y" startspan -->05 Mar 2000<!--webbot bot="Timestamp" endspan i-checksum="14882" -->
|
||||
</p>
|
||||
|
||||
</body>
|
||||
|
||||
</html>
|
||||
110
integer.htm
Normal file
110
integer.htm
Normal file
@ -0,0 +1,110 @@
|
||||
<html>
|
||||
|
||||
<head>
|
||||
<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
|
||||
<meta name="GENERATOR" content="Microsoft FrontPage 4.0">
|
||||
<meta name="ProgId" content="FrontPage.Editor.Document">
|
||||
<title>Integer Type Selection Templates</title>
|
||||
</head>
|
||||
|
||||
<body bgcolor="#FFFFFF" text="#000000">
|
||||
|
||||
<h1><img src="../../c++boost.gif" alt="c++boost.gif (8819 bytes)" align="center" width="277" height="86">Integer
|
||||
Type Selection Templates</h1>
|
||||
<p>The <code><a href="../../boost/integer.hpp"><boost/integer.hpp></a></code>
|
||||
type selection templates allow integer types to be selected based on desired
|
||||
characteristics such as number of bits or maximum value. This facility is
|
||||
particularly useful for solving generic programming problems.</p>
|
||||
|
||||
<p>The templates <b>int_t<></b> and <b>uint_t<></b> supply typedefs <b>least</b>
|
||||
and <b>fast</b>. The <b>least</b> type be the smallest type which holds at
|
||||
least the number of bits (including sign) specified. The <b>fast</b> type will
|
||||
be at least as large as the <b>least</b> type, but may possible be larger.
|
||||
There is no guarantee that the <b>fast</b> type will actually be faster than
|
||||
other possible types.</p>
|
||||
|
||||
<h2>Alternative</h2>
|
||||
|
||||
<p>If the number of bits required is known beforehand, it may be more
|
||||
appropriate to use the types supplied in <code><a href="../../boost/cstdint.hpp"><boost/cstdint.hpp></a></code>.</p>
|
||||
|
||||
<h2>Synopsis</h2>
|
||||
|
||||
<blockquote>
|
||||
<pre>namespace boost
|
||||
{
|
||||
// fast integers from least integers
|
||||
template< typename LeastInt > // Required: LeastInt is integral type, not bool
|
||||
struct int_fast_t { typedef LeastInt fast; }; // implementations may specialize
|
||||
|
||||
// signed
|
||||
template< int Bits > // bits (including sign) required, 0-32 valid
|
||||
struct int_t
|
||||
{
|
||||
typedef <i>implementation-supplied</i> least;
|
||||
typedef int_fast_t<least>::fast fast;
|
||||
};
|
||||
|
||||
// unsigned
|
||||
template< int Bits > // bits required, 0-32 valid
|
||||
struct uint_t
|
||||
{
|
||||
typedef <i>implementation-supplied</i> least;
|
||||
typedef int_fast_t<least>::fast fast;
|
||||
};
|
||||
} // namespace boost
|
||||
</pre>
|
||||
|
||||
</blockquote>
|
||||
<p>[Templates to select type based on maximum value are under development.]
|
||||
</p>
|
||||
|
||||
<h2>Example</h2>
|
||||
|
||||
<blockquote>
|
||||
<pre>#include <boost/integer.hpp>
|
||||
using boost::int_t;
|
||||
|
||||
...
|
||||
int_t<24>::least my_var; </pre>
|
||||
|
||||
</blockquote>
|
||||
<h2>Demonstration Program</h2>
|
||||
|
||||
<p>The program <a href="integer_test.cpp">integer_test.cpp</a> is a not very
|
||||
smart demonstration of the results from instantiating various <b>int_t<></b>
|
||||
and <b>uint_t<></b> examples.</p>
|
||||
|
||||
<h2>Rationale</h2>
|
||||
|
||||
<p>The rationale for the design of the templates in this header includes:</p>
|
||||
|
||||
<ul>
|
||||
<li>Avoid recursion because of concern about C++'s limited guaranteed
|
||||
recursion depth (17).</li>
|
||||
<li>Avoid macros on general principles.</li>
|
||||
<li>Try to keep the design as simple as possible.</li>
|
||||
</ul>
|
||||
|
||||
<h2>Credits</h2>
|
||||
|
||||
<p>The author of the Boost integer type choosing templates is <a href="../../people/beman_dawes.html">Beman
|
||||
Dawes</a>. He thanks to <a href="../../people/valentin_bonnard.htm"> Valentin Bonnard</a> and
|
||||
<a href="../../people/kevlin_henney.htm"> Kevlin Henney</a> for sharing their designs for similar templates.</p>
|
||||
|
||||
<hr>
|
||||
|
||||
<p>Revised August 31, 1999</p>
|
||||
|
||||
<p><EFBFBD> Copyright Beman Dawes 1999. Permission to copy, use, modify, sell
|
||||
and distribute this document is granted provided this copyright notice appears in all
|
||||
copies. This document is provided "as is" without express or implied warranty,
|
||||
and with no claim as to its suitability for any purpose.</p>
|
||||
|
||||
<p></p>
|
||||
|
||||
<p> </p>
|
||||
|
||||
</body>
|
||||
|
||||
</html>
|
||||
89
integer_traits.html
Normal file
89
integer_traits.html
Normal file
@ -0,0 +1,89 @@
|
||||
<html>
|
||||
|
||||
<head>
|
||||
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
|
||||
|
||||
<title>integer_traits: Compile-Time Limits for Integral Types</title>
|
||||
</head>
|
||||
|
||||
<body bgcolor="#FFFFFF" text="#000000">
|
||||
|
||||
<h1><img src="../../c++boost.gif" alt="c++boost.gif (8819 bytes)" align="center" width="277" height="86">Compile-Time Integral
|
||||
Type Limits</h1>
|
||||
|
||||
<p>
|
||||
The C++ Standard Library <limits> header supplies a class template
|
||||
numeric_limits<> with specializations for each fundamental
|
||||
type.</p>
|
||||
<p>
|
||||
For integer types, the interesting members of std::numeric_limits<> are:
|
||||
<pre> static const bool is_specialized; // will be true for integers
|
||||
static T min() throw();
|
||||
static T max() throw();
|
||||
static const int digits; // for integers, # value bits
|
||||
static const int digits10;
|
||||
static const bool is_signed;
|
||||
static const bool is_integer; // will be true for integers</pre>
|
||||
For many uses, these are sufficient. But min() and max() are problematical because they are not constant expressions
|
||||
(std::5.19), yet some usages require constant expressions.
|
||||
<p>
|
||||
The template class <code>integer_traits</code> addresses this
|
||||
problem.
|
||||
|
||||
|
||||
<h2>Header <code><a href="../../boost/integer_traits.hpp">integer_traits.hpp</a></code> Synopsis</h2>
|
||||
|
||||
<pre>namespace boost {
|
||||
template<class T>
|
||||
class integer_traits : public std::numeric_limits<T>
|
||||
{
|
||||
static const bool is_integral = false;
|
||||
};
|
||||
|
||||
// specializations for all integral types
|
||||
}</pre>
|
||||
|
||||
|
||||
<h2>Description</h2>
|
||||
|
||||
Template class <code>integer_traits</code> is derived from
|
||||
<code>std::numeric_limits</code>. In general, it adds the single
|
||||
<code>bool</code> member <code>is_integral</code> with the
|
||||
compile-time constant value <code>false</code>. However, for all
|
||||
integral types <code>T</code> (std::3.9.1/7 [basic.fundamental]),
|
||||
there are specializations provided with the following compile-time
|
||||
constants defined:
|
||||
<p>
|
||||
<table border=1>
|
||||
<tr><th>member</th><th>type</th><th>value</th></tr>
|
||||
<tr><td><code>is_integral</code></td><td>bool</td><td><code>true</code></td></tr>
|
||||
<tr><td><code>const_min</code></td><td><code>T</code></td><td>equivalent
|
||||
to <code>std::numeric_limits<T>::min()</code></td></tr>
|
||||
<tr><td><code>const_max</code></td><td><code>T</code></td><td>equivalent
|
||||
to <code>std::numeric_limits<T>::max()</code></td></tr>
|
||||
</table>
|
||||
|
||||
<p>
|
||||
|
||||
<em>Note:</em> A flag <code>is_integral</code> is provided, because a
|
||||
user-defined integer class should specialize
|
||||
<code>std::numeric_limits<>::is_integer = true</code>,
|
||||
nonetheless compile-time constants <code>const_min</code> and
|
||||
<code>const_max</code> cannot be provided for that user-defined class.
|
||||
|
||||
<h2>
|
||||
|
||||
Test Program</h2>
|
||||
|
||||
<p>
|
||||
|
||||
The program <code><a href="integer_traits_test.cpp">integer_traits_test.cpp</a></code>
|
||||
exercises the <code>integer_traits</code> class.
|
||||
|
||||
<h2>Acknowledgements</h2>
|
||||
|
||||
Beman Dawes, Ed Brey, Steve Cleary, and Nathan Myers discussed the integer
|
||||
traits idea on the boost mailing list in August 1999.
|
||||
<hr>
|
||||
<a href="../../people/jens_maurer.htm">
|
||||
Jens Maurer</a>, 2000-02-20
|
||||
Reference in New Issue
Block a user