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| author | Anas Nashif <anas.nashif@intel.com> | 2012-10-30 12:57:26 -0700 |
|---|---|---|
| committer | Anas Nashif <anas.nashif@intel.com> | 2012-10-30 12:57:26 -0700 |
| commit | 1a78a62555be32868418fe52f8e330c9d0f95d5a (patch) | |
| tree | d3765a80e7d3b9640ec2e930743630cd6b9fce2b /doc/html/hash | |
| download | boost-1a78a62555be32868418fe52f8e330c9d0f95d5a.tar.gz boost-1a78a62555be32868418fe52f8e330c9d0f95d5a.tar.bz2 boost-1a78a62555be32868418fe52f8e330c9d0f95d5a.zip | |
Imported Upstream version 1.49.0upstream/1.49.0
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| -rwxr-xr-x | doc/html/hash/changes.html | 294 | ||||
| -rwxr-xr-x | doc/html/hash/combine.html | 128 | ||||
| -rw-r--r-- | doc/html/hash/custom.html | 124 | ||||
| -rwxr-xr-x | doc/html/hash/disable.html | 69 | ||||
| -rwxr-xr-x | doc/html/hash/links.html | 66 | ||||
| -rwxr-xr-x | doc/html/hash/portability.html | 136 | ||||
| -rwxr-xr-x | doc/html/hash/rationale.html | 95 | ||||
| -rwxr-xr-x | doc/html/hash/reference.html | 386 | ||||
| -rwxr-xr-x | doc/html/hash/tutorial.html | 91 |
10 files changed, 1458 insertions, 0 deletions
diff --git a/doc/html/hash/acknowledgements.html b/doc/html/hash/acknowledgements.html new file mode 100755 index 0000000000..97c364a9cb --- /dev/null +++ b/doc/html/hash/acknowledgements.html @@ -0,0 +1,69 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Acknowledgements</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../hash.html" title="Chapter 10. Boost.Functional/Hash"> +<link rel="prev" href="links.html" title="Links"> +<link rel="next" href="../heap.html" title="Chapter 11. Boost.Heap"> +</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="links.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../hash.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="../heap.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="hash.acknowledgements"></a><a class="link" href="acknowledgements.html" title="Acknowledgements">Acknowledgements</a> +</h2></div></div></div> +<p> + This library is based on the design by Peter Dimov. During the initial development + Joaquín M López Muñoz made many useful suggestions and contributed fixes. + </p> +<p> + The formal review was managed by Thorsten Ottosen, and the library reviewed + by: David Abrahams, Alberto Barbati, Topher Cooper, Caleb Epstein, Dave Harris, + Chris Jefferson, Bronek Kozicki, John Maddock, Tobias Swinger, Jaap Suter, + Rob Stewart and Pavel Vozenilek. Since then, further constructive criticism + has been made by Daniel Krügler, Alexander Nasonov and 沈慧峰. + </p> +<p> + The implementation of the hash function for pointers is based on suggestions + made by Alberto Barbati and Dave Harris. Dave Harris also suggested an important + improvement to <code class="computeroutput"><a class="link" href="reference.html#boost.hash_combine">boost::hash_combine</a></code> + that was taken up. + </p> +<p> + Some useful improvements to the floating point hash algorithm were suggested + by Daniel Krügler. + </p> +<p> + The original implementation came from Jeremy B. Maitin-Shepard's hash table + library, although this is a complete rewrite. + </p> +</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 © 2005-2008 Daniel + James<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="links.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../hash.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="../heap.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/hash/changes.html b/doc/html/hash/changes.html new file mode 100755 index 0000000000..61a9b8be3b --- /dev/null +++ b/doc/html/hash/changes.html @@ -0,0 +1,294 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Change Log</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../hash.html" title="Chapter 10. Boost.Functional/Hash"> +<link rel="prev" href="disable.html" title="Disabling The Extensions"> +<link rel="next" href="rationale.html" title="Rationale"> +</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="disable.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../hash.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="rationale.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="hash.changes"></a><a class="link" href="changes.html" title="Change Log">Change Log</a> +</h2></div></div></div> +<h3> +<a name="hash.changes.h0"></a> + <span><a name="hash.changes.boost_1_33_0"></a></span><a class="link" href="changes.html#hash.changes.boost_1_33_0">Boost + 1.33.0</a> + </h3> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> + Initial Release + </li></ul></div> +<h3> +<a name="hash.changes.h1"></a> + <span><a name="hash.changes.boost_1_33_1"></a></span><a class="link" href="changes.html#hash.changes.boost_1_33_1">Boost + 1.33.1</a> + </h3> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> + Fixed the points example, as pointed out by 沈慧峰. + </li></ul></div> +<h3> +<a name="hash.changes.h2"></a> + <span><a name="hash.changes.boost_1_34_0"></a></span><a class="link" href="changes.html#hash.changes.boost_1_34_0">Boost + 1.34.0</a> + </h3> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"> +<li class="listitem"> + Use declarations for standard classes, so that the library doesn't need + to include all of their headers + </li> +<li class="listitem"> + Deprecated the <code class="computeroutput"><span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">functional</span><span class="special">/</span><span class="identifier">hash</span><span class="comment">/*.hpp></span></code> headers. Now a single header, + <<code class="computeroutput"><a class="link" href="reference.html#header.boost.functional.hash_hpp" title="Header <boost/functional/hash.hpp>">boost/functional/hash.hpp</a></code>> + is used. + </li> +<li class="listitem"> + Add support for the <code class="computeroutput"><span class="identifier">BOOST_HASH_NO_EXTENSIONS</span></code> + macro, which disables the extensions to TR1. + </li> +<li class="listitem"> + Minor improvements to the hash functions for floating point numbers. + </li> +<li class="listitem"> + Update the portable example to hopefully be more generally portable. + </li> +</ul></div> +<h3> +<a name="hash.changes.h3"></a> + <span><a name="hash.changes.boost_1_34_1"></a></span><a class="link" href="changes.html#hash.changes.boost_1_34_1">Boost + 1.34.1</a> + </h3> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> + <a href="http://svn.boost.org/trac/boost/ticket/952" target="_top">Ticket 952</a>: + Suppress incorrect 64-bit warning on Visual C++. + </li></ul></div> +<h3> +<a name="hash.changes.h4"></a> + <span><a name="hash.changes.boost_1_35_0"></a></span><a class="link" href="changes.html#hash.changes.boost_1_35_0">Boost + 1.35.0</a> + </h3> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"> +<li class="listitem"> + Support for <code class="computeroutput"><span class="keyword">long</span> <span class="keyword">long</span></code>, + <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">complex</span></code>. + </li> +<li class="listitem"> + Improved algorithm for hashing floating point numbers: + <div class="itemizedlist"><ul class="itemizedlist" type="circle"> +<li class="listitem"> + Improved portablity, as described by Daniel Krügler in <a href="http://lists.boost.org/boost-users/2005/08/13418.php" target="_top">a + post to the boost users list</a>. + </li> +<li class="listitem"> + Fits more information into each combine loop, which can reduce the + the number of times combine is called and hopefully give a better + quality hash function. + </li> +<li class="listitem"> + Improved the algorithm for hashing floating point numbers. + </li> +<li class="listitem"> + On Cygwin use a binary hash function for floating point numbers, + as Cygwin doesn't have decent floating point functions for <code class="computeroutput"><span class="keyword">long</span> <span class="keyword">double</span></code>. + </li> +<li class="listitem"> + Never uses <code class="computeroutput"><span class="identifier">fpclass</span></code> + which doesn't support <code class="computeroutput"><span class="keyword">long</span> + <span class="keyword">double</span></code>. + </li> +<li class="listitem"> + <a href="http://svn.boost.org/trac/boost/ticket/1064" target="_top">Ticket 1064</a>: + Removed unnecessary use of <code class="computeroutput"><span class="identifier">errno</span></code>. + </li> +</ul></div> + </li> +<li class="listitem"> + Explicitly overload for more built in types. + </li> +<li class="listitem"> + Minor improvements to the documentation. + </li> +<li class="listitem"> + A few bug and warning fixes: + <div class="itemizedlist"><ul class="itemizedlist" type="circle"> +<li class="listitem"> + <a href="http://svn.boost.org/trac/boost/ticket/1509" target="_top">Ticket 1509</a>: + Suppress another Visual C++ warning. + </li> +<li class="listitem"> + Some workarounds for the Sun compilers. + </li> +</ul></div> + </li> +</ul></div> +<h3> +<a name="hash.changes.h5"></a> + <span><a name="hash.changes.boost_1_36_0"></a></span><a class="link" href="changes.html#hash.changes.boost_1_36_0">Boost + 1.36.0</a> + </h3> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"> +<li class="listitem"> + Stop using OpenBSD's dodgy <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">numeric_limits</span></code>. + </li> +<li class="listitem"> + Using the boost typedefs for <code class="computeroutput"><span class="keyword">long</span> + <span class="keyword">long</span></code> and <code class="computeroutput"><span class="keyword">unsigned</span> + <span class="keyword">long</span> <span class="keyword">long</span></code>. + </li> +<li class="listitem"> + Move the extensions into their own header. + </li> +</ul></div> +<h3> +<a name="hash.changes.h6"></a> + <span><a name="hash.changes.boost_1_37_0"></a></span><a class="link" href="changes.html#hash.changes.boost_1_37_0">Boost + 1.37.0</a> + </h3> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> + <a href="http://svn.boost.org/trac/boost/ticket/2264" target="_top">Ticket 2264</a>: + In Visual C++, always use C99 float functions for <code class="computeroutput"><span class="keyword">long</span> + <span class="keyword">double</span></code> and <code class="computeroutput"><span class="keyword">float</span></code> + as the C++ overloads aren't always availables. + </li></ul></div> +<h3> +<a name="hash.changes.h7"></a> + <span><a name="hash.changes.boost_1_38_0"></a></span><a class="link" href="changes.html#hash.changes.boost_1_38_0">Boost + 1.38.0</a> + </h3> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"> +<li class="listitem"> + Changed the warnings in the deprecated headers from 1.34.0 to errors. These + will be removed in a future version of Boost. + </li> +<li class="listitem"> + Moved detail headers out of <code class="computeroutput"><span class="identifier">boost</span><span class="special">/</span><span class="identifier">functional</span><span class="special">/</span><span class="identifier">detail</span></code>, + since they are part of functional/hash, not functional. <code class="computeroutput"><span class="identifier">boost</span><span class="special">/</span><span class="identifier">functional</span><span class="special">/</span><span class="identifier">detail</span><span class="special">/</span><span class="identifier">container_fwd</span><span class="special">.</span><span class="identifier">hpp</span></code> + has been moved to <code class="computeroutput"><span class="identifier">boost</span><span class="special">/</span><span class="identifier">detail</span><span class="special">/</span><span class="identifier">container_fwd</span><span class="special">.</span><span class="identifier">hpp</span></code> + as it's used outside of this library, the others have been moved to <code class="computeroutput"><span class="identifier">boost</span><span class="special">/</span><span class="identifier">functional</span><span class="special">/</span><span class="identifier">hash</span><span class="special">/</span><span class="identifier">detail</span></code>. + </li> +</ul></div> +<h3> +<a name="hash.changes.h8"></a> + <span><a name="hash.changes.boost_1_39_0"></a></span><a class="link" href="changes.html#hash.changes.boost_1_39_0">Boost + 1.39.0</a> + </h3> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"> +<li class="listitem"> + Move the hash_fwd.hpp implementation into the hash subdirectory, leaving + a forwarding header in the old location. You should still use the old location, + the new location is mainly for implementation and possible modularization. + </li> +<li class="listitem"> + <a href="https://svn.boost.org/trac/boost/ticket/2412" target="_top">Ticket 2412</a>: + Removed deprecated headers. + </li> +<li class="listitem"> + <a href="https://svn.boost.org/trac/boost/ticket/2957" target="_top">Ticket 2957</a>: + Fix configuration for vxworks. + </li> +</ul></div> +<h3> +<a name="hash.changes.h9"></a> + <span><a name="hash.changes.boost_1_40_0"></a></span><a class="link" href="changes.html#hash.changes.boost_1_40_0">Boost + 1.40.0</a> + </h3> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"> +<li class="listitem"> + Automatically configure the float functions using template metaprogramming + instead of trying to configure every possibility manually. + </li> +<li class="listitem"> + Workaround for when STLport doesn't support long double. + </li> +</ul></div> +<h3> +<a name="hash.changes.h10"></a> + <span><a name="hash.changes.boost_1_42_0"></a></span><a class="link" href="changes.html#hash.changes.boost_1_42_0">Boost + 1.42.0</a> + </h3> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"> +<li class="listitem"> + Reduce the number of warnings for Visual C++ warning level 4. + </li> +<li class="listitem"> + Some code formatting changes to fit lines into 80 characters. + </li> +<li class="listitem"> + Rename an internal namespace. + </li> +</ul></div> +<h3> +<a name="hash.changes.h11"></a> + <span><a name="hash.changes.boost_1_43_0"></a></span><a class="link" href="changes.html#hash.changes.boost_1_43_0">Boost + 1.43.0</a> + </h3> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"> +<li class="listitem"> + <a href="https://svn.boost.org/trac/boost/ticket/3866" target="_top">Ticket 3866</a>: + Don't foward declare containers when using gcc's parallel library, allow + user to stop forward declaration by defining the <code class="computeroutput"><span class="identifier">BOOST_DETAIL_NO_CONTAINER_FWD</span></code> + macro. + </li> +<li class="listitem"> + <a href="https://svn.boost.org/trac/boost/ticket/4038" target="_top">Ticket 4038</a>: + Avoid hashing 0.5 and 0 to the same number. + </li> +<li class="listitem"> + Stop using deprecated <code class="computeroutput"><span class="identifier">BOOST_HAS_</span><span class="special">*</span></code> macros. + </li> +</ul></div> +<h3> +<a name="hash.changes.h12"></a> + <span><a name="hash.changes.boost_1_44_0"></a></span><a class="link" href="changes.html#hash.changes.boost_1_44_0">Boost + 1.44.0</a> + </h3> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> + Add option to prevent implicit conversions when calling <code class="computeroutput"><span class="identifier">hash_value</span></code> + by defining <code class="computeroutput"><span class="identifier">BOOST_HASH_NO_IMPLICIT_CASTS</span></code>. + When using <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">hash</span></code> for a type that does not have <code class="computeroutput"><span class="identifier">hash_value</span></code> declared but does have an + implicit conversion to a type that does, it would use that implicit conversion + to hash it. Which can sometimes go very wrong, e.g. using a conversion + to bool and only hashing to 2 possible values. Since fixing this is a breaking + change and was only approached quite late in the release cycle with little + discussion it's opt-in for now. This, or something like it, will become + the default in a future version. + </li></ul></div> +<h3> +<a name="hash.changes.h13"></a> + <span><a name="hash.changes.boost_1_46_0"></a></span><a class="link" href="changes.html#hash.changes.boost_1_46_0">Boost + 1.46.0</a> + </h3> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> + Avoid warning due with gcc's <code class="computeroutput"><span class="special">-</span><span class="identifier">Wconversion</span></code> flag. + </li></ul></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 © 2005-2008 Daniel + James<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="disable.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../hash.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="rationale.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/hash/combine.html b/doc/html/hash/combine.html new file mode 100755 index 0000000000..13785cc5a1 --- /dev/null +++ b/doc/html/hash/combine.html @@ -0,0 +1,128 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Combining hash values</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../hash.html" title="Chapter 10. Boost.Functional/Hash"> +<link rel="prev" href="custom.html" title="Extending boost::hash for a custom data type"> +<link rel="next" href="portability.html" title="Portability"> +</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="custom.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../hash.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="portability.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="hash.combine"></a><a class="link" href="combine.html" title="Combining hash values">Combining hash values</a> +</h2></div></div></div> +<p> + Say you have a point class, representing a two dimensional location: + </p> +<pre class="programlisting"><span class="keyword">class</span> <span class="identifier">point</span> +<span class="special">{</span> + <span class="keyword">int</span> <span class="identifier">x</span><span class="special">;</span> + <span class="keyword">int</span> <span class="identifier">y</span><span class="special">;</span> +<span class="keyword">public</span><span class="special">:</span> + <span class="identifier">point</span><span class="special">()</span> <span class="special">:</span> <span class="identifier">x</span><span class="special">(</span><span class="number">0</span><span class="special">),</span> <span class="identifier">y</span><span class="special">(</span><span class="number">0</span><span class="special">)</span> <span class="special">{}</span> + <span class="identifier">point</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">x</span><span class="special">,</span> <span class="keyword">int</span> <span class="identifier">y</span><span class="special">)</span> <span class="special">:</span> <span class="identifier">x</span><span class="special">(</span><span class="identifier">x</span><span class="special">),</span> <span class="identifier">y</span><span class="special">(</span><span class="identifier">y</span><span class="special">)</span> <span class="special">{}</span> + + <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">==(</span><span class="identifier">point</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">other</span><span class="special">)</span> <span class="keyword">const</span> + <span class="special">{</span> + <span class="keyword">return</span> <span class="identifier">x</span> <span class="special">==</span> <span class="identifier">other</span><span class="special">.</span><span class="identifier">x</span> <span class="special">&&</span> <span class="identifier">y</span> <span class="special">==</span> <span class="identifier">other</span><span class="special">.</span><span class="identifier">y</span><span class="special">;</span> + <span class="special">}</span> +<span class="special">};</span> +</pre> +<p> + and you wish to use it as the key for an <code class="computeroutput"><span class="identifier">unordered_map</span></code>. + You need to customise the hash for this structure. To do this we need to combine + the hash values for <code class="computeroutput"><span class="identifier">x</span></code> and + <code class="computeroutput"><span class="identifier">y</span></code>. The function <code class="computeroutput"><a class="link" href="reference.html#boost.hash_combine">boost::hash_combine</a></code> is supplied for + this purpose: + </p> +<pre class="programlisting"><span class="keyword">class</span> <span class="identifier">point</span> +<span class="special">{</span> + <span class="special">...</span> + + <span class="keyword">friend</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">hash_value</span><span class="special">(</span><span class="identifier">point</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">p</span><span class="special">)</span> + <span class="special">{</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">seed</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> + <code class="computeroutput"><a class="link" href="reference.html#boost.hash_combine">boost::hash_combine</a></code><span class="special">(</span><span class="identifier">seed</span><span class="special">,</span> <span class="identifier">p</span><span class="special">.</span><span class="identifier">x</span><span class="special">);</span> + <code class="computeroutput"><a class="link" href="reference.html#boost.hash_combine">boost::hash_combine</a></code><span class="special">(</span><span class="identifier">seed</span><span class="special">,</span> <span class="identifier">p</span><span class="special">.</span><span class="identifier">y</span><span class="special">);</span> + + <span class="keyword">return</span> <span class="identifier">seed</span><span class="special">;</span> + <span class="special">}</span> + + <span class="special">...</span> +<span class="special">};</span> +</pre> +<p> + Calls to hash_combine incrementally build the hash from the different members + of point, it can be repeatedly called for any number of elements. It calls + <code class="computeroutput"><a class="link" href="reference.html#boost.hash_value_id732888">hash_value</a></code> on the supplied + element, and combines it with the seed. + </p> +<p> + Full code for this example is at <a href="../../../libs/functional/hash/examples/point.cpp" target="_top">/libs/functional/hash/examples/point.cpp</a>. + </p> +<div class="note"><table border="0" summary="Note"> +<tr> +<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../doc/src/images/note.png"></td> +<th align="left">Note</th> +</tr> +<tr><td align="left" valign="top"> +<p> + When using <code class="computeroutput"><a class="link" href="reference.html#boost.hash_combine">boost::hash_combine</a></code> + the order of the calls matters. </p> +<pre class="programlisting"> + std::size_t seed = 0; + boost::hash_combine(seed, 1); + boost::hash_combine(seed, 2); +</pre> +<p> +results in a different seed to: +</p> +<pre class="programlisting"> + std::size_t seed = 0; + boost::hash_combine(seed, 2); + boost::hash_combine(seed, 1); +</pre> +<p> +If you are calculating a hash value for data + where the order of the data doesn't matter in comparisons (e.g. a set) you + will have to ensure that the data is always supplied in the same order. + </p> +</td></tr> +</table></div> +<p> + To calculate the hash of an iterator range you can use <code class="computeroutput"><a class="link" href="reference.html#boost.hash_range">boost::hash_range</a></code>: + </p> +<pre class="programlisting"><span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">></span> <span class="identifier">some_strings</span><span class="special">;</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">hash</span> <span class="special">=</span> <code class="computeroutput"><a class="link" href="reference.html#boost.hash_range">boost::hash_range</a></code><span class="special">(</span><span class="identifier">some_strings</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(),</span> <span class="identifier">some_strings</span><span class="special">.</span><span class="identifier">end</span><span class="special">());</span> +</pre> +</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 © 2005-2008 Daniel + James<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="custom.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../hash.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="portability.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/hash/custom.html b/doc/html/hash/custom.html new file mode 100644 index 0000000000..b15b1d728c --- /dev/null +++ b/doc/html/hash/custom.html @@ -0,0 +1,124 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Extending boost::hash for a custom data type</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../hash.html" title="Chapter 10. Boost.Functional/Hash"> +<link rel="prev" href="tutorial.html" title="Tutorial"> +<link rel="next" href="combine.html" title="Combining hash values"> +</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="tutorial.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../hash.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="combine.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="hash.custom"></a><a class="link" href="custom.html" title="Extending boost::hash for a custom data type">Extending boost::hash for a custom data type</a> +</h2></div></div></div> +<p> + <code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code> is implemented by calling + the function <code class="computeroutput"><a class="link" href="reference.html#boost.hash_value_id732888">hash_value</a></code>. + The namespace isn't specified so that it can detect overloads via argument + dependant lookup. So if there is a free function <code class="computeroutput"><span class="identifier">hash_value</span></code> + in the same namespace as a custom type, it will get called. + </p> +<p> + If you have a structure <code class="computeroutput"><span class="identifier">library</span><span class="special">::</span><span class="identifier">book</span></code>, where + each <code class="computeroutput"><span class="identifier">book</span></code> is uniquely defined + by it's member <code class="computeroutput"><span class="identifier">id</span></code>: + </p> +<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">library</span> +<span class="special">{</span> + <span class="keyword">struct</span> <span class="identifier">book</span> + <span class="special">{</span> + <span class="keyword">int</span> <span class="identifier">id</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">author</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">title</span><span class="special">;</span> + + <span class="comment">// ....</span> + <span class="special">};</span> + + <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">==(</span><span class="identifier">book</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">a</span><span class="special">,</span> <span class="identifier">book</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">b</span><span class="special">)</span> + <span class="special">{</span> + <span class="keyword">return</span> <span class="identifier">a</span><span class="special">.</span><span class="identifier">id</span> <span class="special">==</span> <span class="identifier">b</span><span class="special">.</span><span class="identifier">id</span><span class="special">;</span> + <span class="special">}</span> +<span class="special">}</span> +</pre> +<p> + Then all you would need to do is write the function <code class="computeroutput"><span class="identifier">library</span><span class="special">::</span><span class="identifier">hash_value</span></code>: + </p> +<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">library</span> +<span class="special">{</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">hash_value</span><span class="special">(</span><span class="identifier">book</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">b</span><span class="special">)</span> + <span class="special">{</span> + <code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">hasher</span><span class="special">;</span> + <span class="keyword">return</span> <span class="identifier">hasher</span><span class="special">(</span><span class="identifier">b</span><span class="special">.</span><span class="identifier">id</span><span class="special">);</span> + <span class="special">}</span> +<span class="special">}</span> +</pre> +<p> + And you can now use <code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code> with + book: + </p> +<pre class="programlisting"><span class="identifier">library</span><span class="special">::</span><span class="identifier">book</span> <span class="identifier">knife</span><span class="special">(</span><span class="number">3458</span><span class="special">,</span> <span class="string">"Zane Grey"</span><span class="special">,</span> <span class="string">"The Hash Knife Outfit"</span><span class="special">);</span> +<span class="identifier">library</span><span class="special">::</span><span class="identifier">book</span> <span class="identifier">dandelion</span><span class="special">(</span><span class="number">1354</span><span class="special">,</span> <span class="string">"Paul J. Shanley"</span><span class="special">,</span> + <span class="string">"Hash & Dandelion Greens"</span><span class="special">);</span> + +<code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code><span class="special"><</span><span class="identifier">library</span><span class="special">::</span><span class="identifier">book</span><span class="special">></span> <span class="identifier">book_hasher</span><span class="special">;</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">knife_hash_value</span> <span class="special">=</span> <span class="identifier">book_hasher</span><span class="special">(</span><span class="identifier">knife</span><span class="special">);</span> + +<span class="comment">// If std::unordered_set is available:</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">unordered_set</span><span class="special"><</span><span class="identifier">library</span><span class="special">::</span><span class="identifier">book</span><span class="special">,</span> <code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code><span class="special"><</span><span class="identifier">library</span><span class="special">::</span><span class="identifier">book</span><span class="special">></span> <span class="special">></span> <span class="identifier">books</span><span class="special">;</span> +<span class="identifier">books</span><span class="special">.</span><span class="identifier">insert</span><span class="special">(</span><span class="identifier">knife</span><span class="special">);</span> +<span class="identifier">books</span><span class="special">.</span><span class="identifier">insert</span><span class="special">(</span><span class="identifier">library</span><span class="special">::</span><span class="identifier">book</span><span class="special">(</span><span class="number">2443</span><span class="special">,</span> <span class="string">"Lindgren, Torgny"</span><span class="special">,</span> <span class="string">"Hash"</span><span class="special">));</span> +<span class="identifier">books</span><span class="special">.</span><span class="identifier">insert</span><span class="special">(</span><span class="identifier">library</span><span class="special">::</span><span class="identifier">book</span><span class="special">(</span><span class="number">1953</span><span class="special">,</span> <span class="string">"Snyder, Bernadette M."</span><span class="special">,</span> + <span class="string">"Heavenly Hash: A Tasty Mix of a Mother's Meditations"</span><span class="special">));</span> + +<span class="identifier">assert</span><span class="special">(</span><span class="identifier">books</span><span class="special">.</span><span class="identifier">find</span><span class="special">(</span><span class="identifier">knife</span><span class="special">)</span> <span class="special">!=</span> <span class="identifier">books</span><span class="special">.</span><span class="identifier">end</span><span class="special">());</span> +<span class="identifier">assert</span><span class="special">(</span><span class="identifier">books</span><span class="special">.</span><span class="identifier">find</span><span class="special">(</span><span class="identifier">dandelion</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">books</span><span class="special">.</span><span class="identifier">end</span><span class="special">());</span> +</pre> +<p> + The full example can be found in: <a href="../../../libs/functional/hash/examples/books.hpp" target="_top">/libs/functional/hash/examples/books.hpp</a> + and <a href="../../../libs/functional/hash/examples/books.cpp" target="_top">/libs/functional/hash/examples/books.cpp</a>. + </p> +<div class="tip"><table border="0" summary="Tip"> +<tr> +<td rowspan="2" align="center" valign="top" width="25"><img alt="[Tip]" src="../../../doc/src/images/tip.png"></td> +<th align="left">Tip</th> +</tr> +<tr><td align="left" valign="top"><p> + When writing a hash function, first look at how the equality function works. + Objects that are equal must generate the same hash value. When objects are + not equal they should generate different hash values. In this object equality + was based just on the id so the hash function only hashes the id. If it was + based on the object's name and author then the hash function should take + them into account (how to do this is discussed in the next section). + </p></td></tr> +</table></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 © 2005-2008 Daniel + James<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="tutorial.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../hash.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="combine.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/hash/disable.html b/doc/html/hash/disable.html new file mode 100755 index 0000000000..ba42c1ad29 --- /dev/null +++ b/doc/html/hash/disable.html @@ -0,0 +1,69 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Disabling The Extensions</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../hash.html" title="Chapter 10. Boost.Functional/Hash"> +<link rel="prev" href="portability.html" title="Portability"> +<link rel="next" href="changes.html" title="Change Log"> +</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="portability.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../hash.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="changes.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="hash.disable"></a><a class="link" href="disable.html" title="Disabling The Extensions">Disabling The Extensions</a> +</h2></div></div></div> +<p> + While <code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code>'s extensions are + generally useful, you might want to turn them of in order to check that your + code will work with other implementations of TR1. To do this define the macro + <code class="computeroutput"><span class="identifier">BOOST_HASH_NO_EXTENSIONS</span></code>. When + this macro is defined, only the specialisations detailed in TR1 will be declared. + But, if you later undefine the macro and include <<code class="computeroutput"><a class="link" href="reference.html#header.boost.functional.hash_hpp" title="Header <boost/functional/hash.hpp>">boost/functional/hash.hpp</a></code>> + then the non-specialised form will be defined - activating the extensions. + </p> +<p> + It is strongly recommended that you never undefine the macro - and only define + it so that it applies to the complete translation unit, either by defining + it at the beginning of the main source file or, preferably, by using a compiler + switch or preference. And you really should never define it in header files. + </p> +<p> + If you are writing a library which has code in the header which requires the + extensions, then the best action is to tell users not to define the macro. + Their code won't <span class="emphasis"><em>require</em></span> the macro. + </p> +<p> + Translation units that are compiled with the macro defined will link with units + that were compiled without it. This feature has been designed to avoid ODR + violations. + </p> +</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 © 2005-2008 Daniel + James<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="portability.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../hash.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="changes.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/hash/links.html b/doc/html/hash/links.html new file mode 100755 index 0000000000..6d6e375219 --- /dev/null +++ b/doc/html/hash/links.html @@ -0,0 +1,66 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Links</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../hash.html" title="Chapter 10. Boost.Functional/Hash"> +<link rel="prev" href="../boost/hash_std_type_index_id733286.html" title="Struct hash<std::type_index>"> +<link rel="next" href="acknowledgements.html" title="Acknowledgements"> +</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="../boost/hash_std_type_index_id733286.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../hash.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="acknowledgements.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="hash.links"></a><a class="link" href="links.html" title="Links">Links</a> +</h2></div></div></div> +<p> + <span class="bold"><strong>A Proposal to Add Hash Tables to the Standard Library</strong></span> + <a href="http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2003/n1456.html" target="_top">http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2003/n1456.html</a> + The hash table proposal explains much of the design. The hash function object + is discussed in Section D. + </p> +<p> + <span class="bold"><strong>The C++ Standard Library Technical Report.</strong></span> + <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1836.pdf" target="_top">http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1836.pdf</a> + Contains the hash function specification in section 6.3.2. + </p> +<p> + <span class="bold"><strong>Library Extension Technical Report Issues List.</strong></span> + <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1837.pdf" target="_top">http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1837.pdf</a> + The library implements the extension described in Issue 6.18, pages 63-67. + </p> +<p> + <span class="bold"><strong>Methods for Identifying Versioned and Plagiarised Documents</strong></span> + Timothy C. Hoad, Justin Zobel <a href="http://www.cs.rmit.edu.au/~jz/fulltext/jasist-tch.pdf" target="_top">http://www.cs.rmit.edu.au/~jz/fulltext/jasist-tch.pdf</a> + Contains the hash function that <code class="computeroutput"><a class="link" href="reference.html#boost.hash_combine">boost::hash_combine</a></code> + is based on. + </p> +</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 © 2005-2008 Daniel + James<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="../boost/hash_std_type_index_id733286.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../hash.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="acknowledgements.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/hash/portability.html b/doc/html/hash/portability.html new file mode 100755 index 0000000000..48e8f104dc --- /dev/null +++ b/doc/html/hash/portability.html @@ -0,0 +1,136 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Portability</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../hash.html" title="Chapter 10. Boost.Functional/Hash"> +<link rel="prev" href="combine.html" title="Combining hash values"> +<link rel="next" href="disable.html" title="Disabling The Extensions"> +</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="combine.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../hash.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="disable.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="hash.portability"></a><a class="link" href="portability.html" title="Portability">Portability</a> +</h2></div></div></div> +<p> + <code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code> is written to be as portable + as possible, but unfortunately, several older compilers don't support argument + dependent lookup (ADL) - the mechanism used for customisation. On those compilers + custom overloads for <code class="computeroutput"><span class="identifier">hash_value</span></code> + needs to be declared in the boost namespace. + </p> +<p> + On a strictly standards compliant compiler, an overload defined in the boost + namespace won't be found when <code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code> + is instantiated, so for these compilers the overload should only be declared + in the same namespace as the class. + </p> +<p> + Let's say we have a simple custom type: + </p> +<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">foo</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">custom_type</span> + <span class="special">{</span> + <span class="identifier">T</span> <span class="identifier">value</span><span class="special">;</span> + <span class="keyword">public</span><span class="special">:</span> + <span class="identifier">custom_type</span><span class="special">(</span><span class="identifier">T</span> <span class="identifier">x</span><span class="special">)</span> <span class="special">:</span> <span class="identifier">value</span><span class="special">(</span><span class="identifier">x</span><span class="special">)</span> <span class="special">{}</span> + + <span class="keyword">friend</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">hash_value</span><span class="special">(</span><span class="identifier">custom_type</span> <span class="identifier">x</span><span class="special">)</span> + <span class="special">{</span> + <code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">hasher</span><span class="special">;</span> + <span class="keyword">return</span> <span class="identifier">hasher</span><span class="special">(</span><span class="identifier">x</span><span class="special">.</span><span class="identifier">value</span><span class="special">);</span> + <span class="special">}</span> + <span class="special">};</span> +<span class="special">}</span> +</pre> +<p> + On a compliant compiler, when <code class="computeroutput"><span class="identifier">hash_value</span></code> + is called for this type, it will look at the namespace inside the type and + find <code class="computeroutput"><span class="identifier">hash_value</span></code> but on a compiler + which doesn't support ADL <code class="computeroutput"><span class="identifier">hash_value</span></code> + won't be found. To make things worse, some compilers which do support ADL won't + find a friend class defined inside the class. + </p> +<p> + So first move the member function out of the class: + </p> +<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">foo</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">custom_type</span> + <span class="special">{</span> + <span class="identifier">T</span> <span class="identifier">value</span><span class="special">;</span> + <span class="keyword">public</span><span class="special">:</span> + <span class="identifier">custom_type</span><span class="special">(</span><span class="identifier">T</span> <span class="identifier">x</span><span class="special">)</span> <span class="special">:</span> <span class="identifier">value</span><span class="special">(</span><span class="identifier">x</span><span class="special">)</span> <span class="special">{}</span> + + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">hash</span><span class="special">(</span><span class="identifier">custom_type</span> <span class="identifier">x</span><span class="special">)</span> + <span class="special">{</span> + <code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">hasher</span><span class="special">;</span> + <span class="keyword">return</span> <span class="identifier">hasher</span><span class="special">(</span><span class="identifier">value</span><span class="special">);</span> + <span class="special">}</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">inline</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">hash_value</span><span class="special">(</span><span class="identifier">custom_type</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">x</span><span class="special">)</span> + <span class="special">{</span> + <span class="keyword">return</span> <span class="identifier">x</span><span class="special">.</span><span class="identifier">hash</span><span class="special">();</span> + <span class="special">}</span> +<span class="special">}</span> +</pre> +<p> + Unfortunately, I couldn't declare hash_value as a friend, as some compilers + don't support template friends, so instead I declared a member function to + calculate the hash, and called it from hash_value. + </p> +<p> + For compilers which don't support ADL, hash_value needs to be defined in the + boost namespace: + </p> +<pre class="programlisting"><span class="preprocessor">#ifdef</span> <span class="identifier">BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP</span> +<span class="keyword">namespace</span> <span class="identifier">boost</span> +<span class="preprocessor">#else</span> +<span class="keyword">namespace</span> <span class="identifier">foo</span> +<span class="preprocessor">#endif</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="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">hash_value</span><span class="special">(</span><span class="identifier">foo</span><span class="special">::</span><span class="identifier">custom_type</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">x</span><span class="special">)</span> + <span class="special">{</span> + <span class="keyword">return</span> <span class="identifier">x</span><span class="special">.</span><span class="identifier">hash</span><span class="special">();</span> + <span class="special">}</span> +<span class="special">}</span> +</pre> +<p> + Full code for this example is at <a href="../../../libs/functional/hash/examples/portable.cpp" target="_top">/libs/functional/hash/examples/portable.cpp</a>. + </p> +</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 © 2005-2008 Daniel + James<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="combine.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../hash.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="disable.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/hash/rationale.html b/doc/html/hash/rationale.html new file mode 100755 index 0000000000..a389f9eca0 --- /dev/null +++ b/doc/html/hash/rationale.html @@ -0,0 +1,95 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Rationale</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../hash.html" title="Chapter 10. Boost.Functional/Hash"> +<link rel="prev" href="changes.html" title="Change Log"> +<link rel="next" href="reference.html" title="Reference"> +</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="changes.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../hash.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="reference.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="hash.rationale"></a><a class="link" href="rationale.html" title="Rationale">Rationale</a> +</h2></div></div></div> +<p> + The rationale can be found in the original design <sup>[<a name="hash.rationale.f0" href="#ftn.hash.rationale.f0" class="footnote">1</a>]</sup>. + </p> +<h4> +<a name="hash.rationale.h0"></a> + <span><a name="hash.rationale.quality_of_the_hash_function"></a></span><a class="link" href="rationale.html#hash.rationale.quality_of_the_hash_function">Quality + of the hash function</a> + </h4> +<p> + Many hash functions strive to have little correlation between the input and + output values. They attempt to uniformally distribute the output values for + very similar inputs. This hash function makes no such attempt. In fact, for + integers, the result of the hash function is often just the input value. So + similar but different input values will often result in similar but different + output values. This means that it is not appropriate as a general hash function. + For example, a hash table may discard bits from the hash function resulting + in likely collisions, or might have poor collision resolution when hash values + are clustered together. In such cases this hash function will preform poorly. + </p> +<p> + But the standard has no such requirement for the hash function, it just requires + that the hashes of two different values are unlikely to collide. Containers + or algorithms designed to work with the standard hash function will have to + be implemented to work well when the hash function's output is correlated to + its input. Since they are paying that cost a higher quality hash function would + be wasteful. + </p> +<p> + For other use cases, if you do need a higher quality hash function, then neither + the standard hash function or <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">hash</span></code> are + appropriate. There are several options available. One is to use a second hash + on the output of this hash function, such as <a href="http://www.concentric.net/~ttwang/tech/inthash.htm" target="_top">Thomas + Wang's hash function</a>. This this may not work as well as a hash algorithm + tailored for the input. + </p> +<p> + For strings that are several fast, high quality hash functions available (for + example <a href="http://code.google.com/p/smhasher/" target="_top">MurmurHash3</a> + and <a href="http://code.google.com/p/cityhash/" target="_top">Google's CityHash</a>), + although they tend to be more machine specific. These may also be appropriate + for hashing a binary representation of your data - providing that all equal + values have an equal representation, which is not always the case (e.g. for + floating point values). + </p> +<div class="footnotes"> +<br><hr width="100" align="left"> +<div class="footnote"><p><sup>[<a id="ftn.hash.rationale.f0" href="#hash.rationale.f0" class="para">1</a>] </sup> + issue 6.18 of the <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1837.pdf" target="_top">Library + Extension Technical Report Issues List</a> (page 63) + </p></div> +</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 © 2005-2008 Daniel + James<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="changes.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../hash.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="reference.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/hash/reference.html b/doc/html/hash/reference.html new file mode 100755 index 0000000000..dbe2bd55d3 --- /dev/null +++ b/doc/html/hash/reference.html @@ -0,0 +1,386 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Reference</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../hash.html" title="Chapter 10. Boost.Functional/Hash"> +<link rel="prev" href="rationale.html" title="Rationale"> +<link rel="next" href="../boost/hash.html" title="Struct template hash"> +</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="rationale.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../hash.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="../boost/hash.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="hash.reference"></a>Reference</h2></div></div></div> +<div class="toc"><dl> +<dt><span class="section"><a href="reference.html#hash.reference.specification"></a></span></dt> +<dt><span class="section"><a href="reference.html#header.boost.functional.hash_hpp">Header <boost/functional/hash.hpp></a></span></dt> +</dl></div> +<div class="section"> +<div class="titlepage"></div> +<p>For the full specification, see section 6.3 of the + <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1836.pdf" target="_top">C++ Standard Library Technical Report</a> + and issue 6.18 of the + <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1837.pdf" target="_top">Library Extension Technical Report Issues List</a> (page 63). + </p> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.functional.hash_hpp"></a>Header <<a href="../../../boost/functional/hash.hpp" target="_top">boost/functional/hash.hpp</a>></h3></div></div></div> +<p> + Defines <code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code>, + and helper functions. + </p> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash.html" title="Struct template hash">hash</a><span class="special">;</span> + + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash_bool_id730163.html" title="Struct hash<bool>">hash</a><span class="special"><</span><span class="keyword">bool</span><span class="special">></span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash_char_id727549.html" title="Struct hash<char>">hash</a><span class="special"><</span><span class="keyword">char</span><span class="special">></span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash_signed_char_id750069.html" title="Struct hash<signed char>">hash</a><span class="special"><</span><span class="keyword">signed</span> <span class="keyword">char</span><span class="special">></span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash_unsigned_char_id750126.html" title="Struct hash<unsigned char>">hash</a><span class="special"><</span><span class="keyword">unsigned</span> <span class="keyword">char</span><span class="special">></span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash_wchar_t_id729419.html" title="Struct hash<wchar_t>">hash</a><span class="special"><</span><span class="keyword">wchar_t</span><span class="special">></span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash_short_id729476.html" title="Struct hash<short>">hash</a><span class="special"><</span><span class="keyword">short</span><span class="special">></span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash_unsigned_short_id751876.html" title="Struct hash<unsigned short>">hash</a><span class="special"><</span><span class="keyword">unsigned</span> <span class="keyword">short</span><span class="special">></span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash_int_id729311.html" title="Struct hash<int>">hash</a><span class="special"><</span><span class="keyword">int</span><span class="special">></span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash_unsigned_int_id729368.html" title="Struct hash<unsigned int>">hash</a><span class="special"><</span><span class="keyword">unsigned</span> <span class="keyword">int</span><span class="special">></span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash_long_id749200.html" title="Struct hash<long>">hash</a><span class="special"><</span><span class="keyword">long</span><span class="special">></span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash_unsigned_long_id749256.html" title="Struct hash<unsigned long>">hash</a><span class="special"><</span><span class="keyword">unsigned</span> <span class="keyword">long</span><span class="special">></span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash_long_long_id752641.html" title="Struct hash<long long>">hash</a><span class="special"><</span><span class="keyword">long</span> <span class="keyword">long</span><span class="special">></span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash_unsigned_long_long_id732192.html" title="Struct hash<unsigned long long>">hash</a><span class="special"><</span><span class="keyword">unsigned</span> <span class="keyword">long</span> <span class="keyword">long</span><span class="special">></span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash_float_id732249.html" title="Struct hash<float>">hash</a><span class="special"><</span><span class="keyword">float</span><span class="special">></span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash_double_id731143.html" title="Struct hash<double>">hash</a><span class="special"><</span><span class="keyword">double</span><span class="special">></span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash_long_double_id731200.html" title="Struct hash<long double>">hash</a><span class="special"><</span><span class="keyword">long</span> <span class="keyword">double</span><span class="special">></span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash_std_string_id729518.html" title="Struct hash<std::string>">hash</a><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">></span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash_std_wstring_id729575.html" title="Struct hash<std::wstring>">hash</a><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">wstring</span><span class="special">></span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash_T_id731670.html" title="Struct template hash<T*>">hash</a><span class="special"><</span><span class="identifier">T</span><span class="special">*</span><span class="special">></span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/hash_std_type_index_id733286.html" title="Struct hash<std::type_index>">hash</a><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">type_index</span><span class="special">></span><span class="special">;</span> + + <span class="comment">// <a class="link" href="reference.html#id725825-bb">Support functions (Boost extension).</a></span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">void</span> <a class="link" href="reference.html#boost.hash_combine"><span class="identifier">hash_combine</span></a><span class="special">(</span><span class="identifier">size_t</span> <span class="special">&</span><span class="special">,</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> It<span class="special">></span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id725365-bb"><span class="identifier">hash_range</span></a><span class="special">(</span><span class="identifier">It</span><span class="special">,</span> <span class="identifier">It</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> It<span class="special">></span> <span class="keyword">void</span> <a class="link" href="reference.html#id725394-bb"><span class="identifier">hash_range</span></a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span><span class="special">&</span><span class="special">,</span> <span class="identifier">It</span><span class="special">,</span> <span class="identifier">It</span><span class="special">)</span><span class="special">;</span> + + <span class="comment">// <a class="link" href="reference.html#id731266-bb">Overloadable hash implementation (Boost extension).</a></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id732898-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="keyword">bool</span><span class="special">)</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id732913-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="keyword">char</span><span class="special">)</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id732927-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="keyword">signed</span> <span class="keyword">char</span><span class="special">)</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id732959-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="keyword">unsigned</span> <span class="keyword">char</span><span class="special">)</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id732974-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="keyword">wchar_t</span><span class="special">)</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id729013-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="keyword">short</span><span class="special">)</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id732865-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="keyword">unsigned</span> <span class="keyword">short</span><span class="special">)</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id732994-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id733008-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="keyword">unsigned</span> <span class="keyword">int</span><span class="special">)</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id733023-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="keyword">long</span><span class="special">)</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id733037-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="keyword">unsigned</span> <span class="keyword">long</span><span class="special">)</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id728759-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="keyword">long</span> <span class="keyword">long</span><span class="special">)</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id730771-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="keyword">unsigned</span> <span class="keyword">long</span> <span class="keyword">long</span><span class="special">)</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id731085-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="keyword">float</span><span class="special">)</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id729126-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="keyword">double</span><span class="special">)</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id729141-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="keyword">long</span> <span class="keyword">double</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id650142-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="identifier">T</span><span class="special">*</span> <span class="keyword">const</span><span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">unsigned</span> N<span class="special">></span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id748098-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="identifier">T</span> <span class="special">(</span><span class="special">&</span><span class="identifier">val</span><span class="special">)</span><span class="special">[</span><span class="identifier">N</span><span class="special">]</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">unsigned</span> N<span class="special">></span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id732878-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">T</span> <span class="special">(</span><span class="special">&</span><span class="identifier">val</span><span class="special">)</span><span class="special">[</span><span class="identifier">N</span><span class="special">]</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Ch<span class="special">,</span> <span class="keyword">typename</span> A<span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id724777-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span><span class="special"><</span><span class="identifier">Ch</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">char_traits</span><span class="special"><</span><span class="identifier">Ch</span><span class="special">></span><span class="special">,</span> <span class="identifier">A</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> A<span class="special">,</span> <span class="keyword">typename</span> B<span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id724808-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special"><</span><span class="identifier">A</span><span class="special">,</span> <span class="identifier">B</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> A<span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id724836-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span><span class="identifier">T</span><span class="special">,</span> <span class="identifier">A</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> A<span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id751089-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">list</span><span class="special"><</span><span class="identifier">T</span><span class="special">,</span> <span class="identifier">A</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> A<span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id728269-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">deque</span><span class="special"><</span><span class="identifier">T</span><span class="special">,</span> <span class="identifier">A</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> K<span class="special">,</span> <span class="keyword">typename</span> C<span class="special">,</span> <span class="keyword">typename</span> A<span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id728297-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">set</span><span class="special"><</span><span class="identifier">K</span><span class="special">,</span> <span class="identifier">C</span><span class="special">,</span> <span class="identifier">A</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> K<span class="special">,</span> <span class="keyword">typename</span> C<span class="special">,</span> <span class="keyword">typename</span> A<span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id728329-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">multiset</span><span class="special"><</span><span class="identifier">K</span><span class="special">,</span> <span class="identifier">C</span><span class="special">,</span> <span class="identifier">A</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> K<span class="special">,</span> <span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> C<span class="special">,</span> <span class="keyword">typename</span> A<span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id728361-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">map</span><span class="special"><</span><span class="identifier">K</span><span class="special">,</span> <span class="identifier">T</span><span class="special">,</span> <span class="identifier">C</span><span class="special">,</span> <span class="identifier">A</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> K<span class="special">,</span> <span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> C<span class="special">,</span> <span class="keyword">typename</span> A<span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id728397-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">multimap</span><span class="special"><</span><span class="identifier">K</span><span class="special">,</span> <span class="identifier">T</span><span class="special">,</span> <span class="identifier">C</span><span class="special">,</span> <span class="identifier">A</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id732938-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">complex</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="reference.html#id728893-bb"><span class="identifier">hash_value</span></a><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">type_index</span><span class="special">)</span><span class="special">;</span> +<span class="special">}</span></pre> +<div class="refsect2"> +<a name="id1560549"></a><h3> +<a name="id725825-bb"></a><code class="computeroutput"></code> Support functions (Boost extension).</h3> +<div class="orderedlist"><ol class="orderedlist" type="1"> +<li class="listitem"> +<pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">void</span> <a name="boost.hash_combine"></a><span class="identifier">hash_combine</span><span class="special">(</span><span class="identifier">size_t</span> <span class="special">&</span> seed<span class="special">,</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&</span> v<span class="special">)</span><span class="special">;</span></pre> +<p class="simpara"> + Called repeatedly to incrementally create a hash value from + several variables. + </p> +<div class="variablelist"><table border="0"> +<col align="left" valign="top"> +<tbody> +<tr> +<td><p><span class="term">Effects:</span></p></td> +<td><pre class="programlisting"><span class="identifier">seed</span> <span class="special">^=</span> <a class="link" href="reference.html#boost.hash_value_id732888">hash_value</a><span class="special">(</span><span class="identifier">v</span><span class="special">)</span> <span class="special">+</span> <span class="number">0x9e3779b9</span> <span class="special">+</span> <span class="special">(</span><span class="identifier">seed</span> <span class="special"><<</span> <span class="number">6</span><span class="special">)</span> <span class="special">+</span> <span class="special">(</span><span class="identifier">seed</span> <span class="special">>></span> <span class="number">2</span><span class="special">)</span><span class="special">;</span></pre></td> +</tr> +<tr> +<td><p><span class="term">Notes:</span></p></td> +<td> +<p><a class="link" href="reference.html#boost.hash_value_id732888">hash_value</a> is called without + qualification, so that overloads can be found via ADL.</p> +<p>This is an extension to TR1</p> +</td> +</tr> +<tr> +<td><p><span class="term">Throws:</span></p></td> +<td> + Only throws if <a class="link" href="reference.html#boost.hash_value_id732888">hash_value</a>(T) throws. + Strong exception safety, as long as <a class="link" href="reference.html#boost.hash_value_id732888">hash_value</a>(T) + also has strong exception safety. + </td> +</tr> +</tbody> +</table></div> +</li> +<li class="listitem"> +<p><a name="boost.hash_range"></a></p> +<pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> It<span class="special">></span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id725365-bb"></a><span class="identifier">hash_range</span><span class="special">(</span><span class="identifier">It</span> first<span class="special">,</span> <span class="identifier">It</span> last<span class="special">)</span><span class="special">;</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> It<span class="special">></span> <span class="keyword">void</span> <a name="id725394-bb"></a><span class="identifier">hash_range</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span><span class="special">&</span> seed<span class="special">,</span> <span class="identifier">It</span> first<span class="special">,</span> <span class="identifier">It</span> last<span class="special">)</span><span class="special">;</span></pre> +<p class="simpara"> + Calculate the combined hash value of the elements of an iterator + range. + </p> +<div class="variablelist"><table border="0"> +<col align="left" valign="top"> +<tbody> +<tr> +<td><p><span class="term">Effects:</span></p></td> +<td> +<p>For the two argument overload: +</p> +<pre class="programlisting"> +<span class="identifier">size_t</span> <span class="identifier">seed</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> + +<span class="keyword">for</span><span class="special">(</span><span class="special">;</span> <span class="identifier">first</span> <span class="special">!=</span> <span class="identifier">last</span><span class="special">;</span> <span class="special">++</span><span class="identifier">first</span><span class="special">)</span> +<span class="special">{</span> + <a class="link" href="reference.html#boost.hash_combine">hash_combine</a><span class="special">(</span><span class="identifier">seed</span><span class="special">,</span> <span class="special">*</span><span class="identifier">first</span><span class="special">)</span><span class="special">;</span> +<span class="special">}</span> + +<span class="keyword">return</span> <span class="identifier">seed</span><span class="special">;</span> +</pre> +<p> + </p>For the three arguments overload: +<pre class="programlisting"> +<span class="keyword">for</span><span class="special">(</span><span class="special">;</span> <span class="identifier">first</span> <span class="special">!=</span> <span class="identifier">last</span><span class="special">;</span> <span class="special">++</span><span class="identifier">first</span><span class="special">)</span> +<span class="special">{</span> + <a class="link" href="reference.html#boost.hash_combine">hash_combine</a><span class="special">(</span><span class="identifier">seed</span><span class="special">,</span> <span class="special">*</span><span class="identifier">first</span><span class="special">)</span><span class="special">;</span> +<span class="special">}</span> +</pre> +<p> + </p> +</td> +</tr> +<tr> +<td><p><span class="term">Notes:</span></p></td> +<td> +<p> + <code class="computeroutput">hash_range</code> is sensitive to the order of the elements + so it wouldn't be appropriate to use this with an unordered + container. + </p> +<p>This is an extension to TR1</p> +</td> +</tr> +<tr> +<td><p><span class="term">Throws:</span></p></td> +<td><p> + Only throws if <code class="computeroutput"><a class="link" href="reference.html#boost.hash_value_id732888">hash_value</a>(std::iterator_traits<It>::value_type)</code> + throws. <code class="computeroutput">hash_range(std::size_t&, It, It)</code> has basic exception safety as long as + <code class="computeroutput"><a class="link" href="reference.html#boost.hash_value_id732888">hash_value</a>(std::iterator_traits<It>::value_type)</code> + has basic exception safety. + </p></td> +</tr> +</tbody> +</table></div> +</li> +</ol></div> +</div> +<div class="refsect2"> +<a name="id1561316"></a><h3> +<a name="id731266-bb"></a><code class="computeroutput"></code> Overloadable hash implementation (Boost extension).</h3> +<div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"> +<p><a name="boost.hash_value_id732888"></a></p> +<pre class="literallayout"><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id732898-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="keyword">bool</span> val<span class="special">)</span><span class="special">;</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id732913-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="keyword">char</span> val<span class="special">)</span><span class="special">;</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id732927-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="keyword">signed</span> <span class="keyword">char</span> val<span class="special">)</span><span class="special">;</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id732959-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="keyword">unsigned</span> <span class="keyword">char</span> val<span class="special">)</span><span class="special">;</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id732974-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="keyword">wchar_t</span> val<span class="special">)</span><span class="special">;</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id729013-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="keyword">short</span> val<span class="special">)</span><span class="special">;</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id732865-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="keyword">unsigned</span> <span class="keyword">short</span> val<span class="special">)</span><span class="special">;</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id732994-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="keyword">int</span> val<span class="special">)</span><span class="special">;</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id733008-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="keyword">unsigned</span> <span class="keyword">int</span> val<span class="special">)</span><span class="special">;</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id733023-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="keyword">long</span> val<span class="special">)</span><span class="special">;</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id733037-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="keyword">unsigned</span> <span class="keyword">long</span> val<span class="special">)</span><span class="special">;</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id728759-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="keyword">long</span> <span class="keyword">long</span> val<span class="special">)</span><span class="special">;</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id730771-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="keyword">unsigned</span> <span class="keyword">long</span> <span class="keyword">long</span> val<span class="special">)</span><span class="special">;</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id731085-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="keyword">float</span> val<span class="special">)</span><span class="special">;</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id729126-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="keyword">double</span> val<span class="special">)</span><span class="special">;</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id729141-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="keyword">long</span> <span class="keyword">double</span> val<span class="special">)</span><span class="special">;</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id650142-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="identifier">T</span><span class="special">*</span> <span class="keyword">const</span><span class="special">&</span> val<span class="special">)</span><span class="special">;</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">unsigned</span> N<span class="special">></span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id748098-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="identifier">T</span> <span class="special">(</span><span class="special">&</span><span class="identifier">val</span><span class="special">)</span><span class="special">[</span><span class="identifier">N</span><span class="special">]</span><span class="special">)</span><span class="special">;</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">unsigned</span> N<span class="special">></span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id732878-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">T</span> <span class="special">(</span><span class="special">&</span><span class="identifier">val</span><span class="special">)</span><span class="special">[</span><span class="identifier">N</span><span class="special">]</span><span class="special">)</span><span class="special">;</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Ch<span class="special">,</span> <span class="keyword">typename</span> A<span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id724777-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span><span class="special"><</span><span class="identifier">Ch</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">char_traits</span><span class="special"><</span><span class="identifier">Ch</span><span class="special">></span><span class="special">,</span> <span class="identifier">A</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> val<span class="special">)</span><span class="special">;</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> A<span class="special">,</span> <span class="keyword">typename</span> B<span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id724808-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special"><</span><span class="identifier">A</span><span class="special">,</span> <span class="identifier">B</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> val<span class="special">)</span><span class="special">;</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> A<span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id724836-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span><span class="identifier">T</span><span class="special">,</span> <span class="identifier">A</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> val<span class="special">)</span><span class="special">;</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> A<span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id751089-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">list</span><span class="special"><</span><span class="identifier">T</span><span class="special">,</span> <span class="identifier">A</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> val<span class="special">)</span><span class="special">;</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> A<span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id728269-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">deque</span><span class="special"><</span><span class="identifier">T</span><span class="special">,</span> <span class="identifier">A</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> val<span class="special">)</span><span class="special">;</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> K<span class="special">,</span> <span class="keyword">typename</span> C<span class="special">,</span> <span class="keyword">typename</span> A<span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id728297-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">set</span><span class="special"><</span><span class="identifier">K</span><span class="special">,</span> <span class="identifier">C</span><span class="special">,</span> <span class="identifier">A</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> val<span class="special">)</span><span class="special">;</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> K<span class="special">,</span> <span class="keyword">typename</span> C<span class="special">,</span> <span class="keyword">typename</span> A<span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id728329-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">multiset</span><span class="special"><</span><span class="identifier">K</span><span class="special">,</span> <span class="identifier">C</span><span class="special">,</span> <span class="identifier">A</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> val<span class="special">)</span><span class="special">;</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> K<span class="special">,</span> <span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> C<span class="special">,</span> <span class="keyword">typename</span> A<span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id728361-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">map</span><span class="special"><</span><span class="identifier">K</span><span class="special">,</span> <span class="identifier">T</span><span class="special">,</span> <span class="identifier">C</span><span class="special">,</span> <span class="identifier">A</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> val<span class="special">)</span><span class="special">;</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> K<span class="special">,</span> <span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> C<span class="special">,</span> <span class="keyword">typename</span> A<span class="special">></span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id728397-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">multimap</span><span class="special"><</span><span class="identifier">K</span><span class="special">,</span> <span class="identifier">T</span><span class="special">,</span> <span class="identifier">C</span><span class="special">,</span> <span class="identifier">A</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> val<span class="special">)</span><span class="special">;</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id732938-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">complex</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="keyword">const</span><span class="special">&</span> val<span class="special">)</span><span class="special">;</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="id728893-bb"></a><span class="identifier">hash_value</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">type_index</span> val<span class="special">)</span><span class="special">;</span></pre> +<p class="simpara"> + Implementation of the hash function. + </p> +<p> + Generally shouldn't be called directly by users, instead they should use + <code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code>, <code class="computeroutput"><a class="link" href="reference.html#boost.hash_range">boost::hash_range</a></code> + or <code class="computeroutput"><a class="link" href="reference.html#boost.hash_combine">boost::hash_combine</a></code> which + call <code class="computeroutput">hash_value</code> without namespace qualification so that overloads + for custom types are found via ADL. + </p> +<div class="variablelist"><table border="0"> +<col align="left" valign="top"> +<tbody> +<tr> +<td><p><span class="term">Notes:</span></p></td> +<td><p>This is an extension to TR1</p></td> +</tr> +<tr> +<td><p><span class="term">Throws:</span></p></td> +<td> + Only throws if a user supplied version of + <code class="computeroutput"><a class="link" href="reference.html#boost.hash_value_id732888">hash_value</a></code> + throws for an element of a container, or + one of the types stored in a pair. + </td> +</tr> +<tr> +<td><p><span class="term">Returns:</span></p></td> +<td><div class="informaltable"><table class="table"> +<colgroup> +<col> +<col> +</colgroup> +<thead><tr> +<th>Types</th> +<th>Returns</th> +</tr></thead> +<tbody> +<tr> +<td> +<code class="computeroutput">bool</code>, + <code class="computeroutput">char</code>, <code class="computeroutput">signed char</code>, <code class="computeroutput">unsigned char</code>, <code class="computeroutput">wchar_t</code>, + <code class="computeroutput">short</code>, <code class="computeroutput">unsigned short</code>, + <code class="computeroutput">int</code>, <code class="computeroutput">unsigned int</code>, <code class="computeroutput">long</code>, <code class="computeroutput">unsigned long</code> + </td> +<td><code class="computeroutput">val</code></td> +</tr> +<tr> +<td> +<code class="computeroutput">long long</code>, <code class="computeroutput">unsigned long long</code> +</td> +<td> +<code class="computeroutput">val</code> when <code class="computeroutput">abs(val) <= std::numeric_limits<std::size_t>::max()</code>.</td> +</tr> +<tr> +<td> +<code class="computeroutput">float</code>, <code class="computeroutput">double</code>, <code class="computeroutput">long double</code> +</td> +<td>An unspecified value, except that equal arguments shall yield the same result.</td> +</tr> +<tr> +<td><code class="computeroutput">T*</code></td> +<td>An unspecified value, except that equal arguments shall yield the same result.</td> +</tr> +<tr> +<td> + <code class="computeroutput">T val[N]</code>, + <code class="computeroutput">const T val[N]</code> + </td> +<td><code class="computeroutput">hash_range(val, val+N)</code></td> +</tr> +<tr> +<td> + <code class="computeroutput">std:basic_string<Ch, std::char_traits<Ch>, A></code>, + <code class="computeroutput">std::vector<T, A></code>, + <code class="computeroutput">std::list<T, A></code>, + <code class="computeroutput">std::deque<T, A></code>, + <code class="computeroutput">std::set<K, C, A></code>, + <code class="computeroutput">std::multiset<K, C, A></code>, + <code class="computeroutput">std::map<K, T, C, A></code>, + <code class="computeroutput">std::multimap<K, T, C, A></code> + </td> +<td><code class="computeroutput">hash_range(val.begin(), val.end())</code></td> +</tr> +<tr> +<td><code class="computeroutput">std::pair<A, B></code></td> +<td><pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="identifier">size_t</span> <span class="identifier">seed</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> +<a class="link" href="reference.html#boost.hash_combine">hash_combine</a><span class="special">(</span><span class="identifier">seed</span><span class="special">,</span> <span class="identifier">val</span><span class="special">.</span><span class="identifier">first</span><span class="special">)</span><span class="special">;</span> +<a class="link" href="reference.html#boost.hash_combine">hash_combine</a><span class="special">(</span><span class="identifier">seed</span><span class="special">,</span> <span class="identifier">val</span><span class="special">.</span><span class="identifier">second</span><span class="special">)</span><span class="special">;</span> +<span class="keyword">return</span> <span class="identifier">seed</span><span class="special">;</span></pre></td> +</tr> +<tr> +<td> + <code class="computeroutput">std::complex<T></code> + </td> +<td>When <code class="computeroutput">T</code> is a built in type and <code class="computeroutput">val.imag() == 0</code>, the result is equal to <code class="computeroutput">hash_value(val.real())</code>. Otherwise an unspecified value, except that equal arguments shall yield the same result.</td> +</tr> +<tr> +<td> + <code class="computeroutput">std::type_index</code> + </td> +<td><code class="computeroutput">val.hash_code()</code></td> +</tr> +</tbody> +</table></div></td> +</tr> +</tbody> +</table></div> +</li></ol></div> +</div> +</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 © 2005-2008 Daniel + James<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="rationale.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../hash.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="../boost/hash.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/hash/tutorial.html b/doc/html/hash/tutorial.html new file mode 100755 index 0000000000..fdf25a487f --- /dev/null +++ b/doc/html/hash/tutorial.html @@ -0,0 +1,91 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Tutorial</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../hash.html" title="Chapter 10. Boost.Functional/Hash"> +<link rel="prev" href="../hash.html" title="Chapter 10. Boost.Functional/Hash"> +<link rel="next" href="custom.html" title="Extending boost::hash for a custom data type"> +</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="../hash.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../hash.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="custom.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="hash.tutorial"></a><a class="link" href="tutorial.html" title="Tutorial">Tutorial</a> +</h2></div></div></div> +<p> + When using a hash index with <a href="../../../libs/multi_index/doc/index.html" target="_top">Boost.MultiIndex</a>, + you don't need to do anything to use <code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code> + as it uses it by default. To find out how to use a user-defined type, read + the <a class="link" href="custom.html" title="Extending boost::hash for a custom data type">section on extending boost::hash for a custom + data type</a>. + </p> +<p> + If your standard library supplies its own implementation of the unordered associative + containers and you wish to use <code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code>, + just use an extra template parameter: + </p> +<pre class="programlisting"><span class="identifier">std</span><span class="special">::</span><span class="identifier">unordered_multiset</span><span class="special"><</span><span class="keyword">int</span><span class="special">,</span> <code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="special">></span> + <span class="identifier">set_of_ints</span><span class="special">;</span> + +<span class="identifier">std</span><span class="special">::</span><span class="identifier">unordered_set</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special"><</span><span class="keyword">int</span><span class="special">,</span> <span class="keyword">int</span><span class="special">>,</span> <code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special"><</span><span class="keyword">int</span><span class="special">,</span> <span class="keyword">int</span><span class="special">></span> <span class="special">></span> + <span class="identifier">set_of_pairs</span><span class="special">;</span> + +<span class="identifier">std</span><span class="special">::</span><span class="identifier">unordered_map</span><span class="special"><</span><span class="keyword">int</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">,</span> <code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="special">></span> <span class="identifier">map_int_to_string</span><span class="special">;</span> +</pre> +<p> + To use <code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code> directly, create + an instance and call it as a function: + </p> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><code class="computeroutput"><a class="link" href="reference.html#header.boost.functional.hash_hpp" title="Header <boost/functional/hash.hpp>">boost/functional/hash.hpp</a></code><span class="special">></span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> +<span class="special">{</span> + <code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">></span> <span class="identifier">string_hash</span><span class="special">;</span> + + <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">h</span> <span class="special">=</span> <span class="identifier">string_hash</span><span class="special">(</span><span class="string">"Hash me"</span><span class="special">);</span> +<span class="special">}</span> +</pre> +<p> + For an example of generic use, here is a function to generate a vector containing + the hashes of the elements of a container: + </p> +<pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">Container</span><span class="special">></span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span><span class="special">></span> <span class="identifier">get_hashes</span><span class="special">(</span><span class="identifier">Container</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">x</span><span class="special">)</span> +<span class="special">{</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span><span class="special">></span> <span class="identifier">hashes</span><span class="special">;</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">transform</span><span class="special">(</span><span class="identifier">x</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(),</span> <span class="identifier">x</span><span class="special">.</span><span class="identifier">end</span><span class="special">(),</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">insert_iterator</span><span class="special">(</span><span class="identifier">hashes</span><span class="special">),</span> + <code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Container</span><span class="special">::</span><span class="identifier">value_type</span><span class="special">>());</span> + + <span class="keyword">return</span> <span class="identifier">hashes</span><span class="special">;</span> +<span class="special">}</span> +</pre> +</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 © 2005-2008 Daniel + James<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="../hash.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../hash.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="custom.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> |