boost-react-native-bundle

<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 V1.78.1"> <link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> <link rel="up" href="../hash.html" title="Chapter 12. 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 class="toc"> <dt><a href="reference.html#hash.reference.specification"></a></dt> <dt><a href="reference.html#header.boost.functional.hash_hpp">Header <boost/functional/hash.hpp></a></dt> </dl></div> <div class="section"> <div class="titlepage"></div> 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). </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> Defines <code class="computeroutput"><a class="link" href="../boost/hash.html" title="Struct template hash">boost::hash</a></code>, and helper functions. <pre class="synopsis">namespace boost { template<typename T> struct <a class="link" href="../boost/hash.html" title="Struct template hash">hash</a>; template<> struct <a class="link" href="../boost/hash_bool_idp40945552.html" title="Struct hash<bool>">hash</a><bool>; template<> struct <a class="link" href="../boost/hash_char_idp47308912.html" title="Struct hash<char>">hash</a><char>; template<> struct <a class="link" href="../boost/hash_signed_c_idp107103920.html" title="Struct hash<signed char>">hash</a><signed char>; template<> struct <a class="link" href="../boost/hash_unsigned__idp40289168.html" title="Struct hash<unsigned char>">hash</a><unsigned char>; template<> struct <a class="link" href="../boost/hash_wchar_t_idp100085152.html" title="Struct hash<wchar_t>">hash</a><wchar_t>; template<> struct <a class="link" href="../boost/hash_short_idp113232624.html" title="Struct hash<short>">hash</a><short>; template<> struct <a class="link" href="../boost/hash_unsigned__idp94408624.html" title="Struct hash<unsigned short>">hash</a><unsigned short>; template<> struct <a class="link" href="../boost/hash_int_idp38064256.html" title="Struct hash<int>">hash</a><int>; template<> struct <a class="link" href="../boost/hash_unsigned__idp48534896.html" title="Struct hash<unsigned int>">hash</a><unsigned int>; template<> struct <a class="link" href="../boost/hash_long_idp100971824.html" title="Struct hash<long>">hash</a><long>; template<> struct <a class="link" href="../boost/hash_unsigned__idp44420688.html" title="Struct hash<unsigned long>">hash</a><unsigned long>; template<> struct <a class="link" href="../boost/hash_long_lon_idp101636672.html" title="Struct hash<long long>">hash</a><long long>; template<> struct <a class="link" href="../boost/hash_unsigned__idp71328176.html" title="Struct hash<unsigned long long>">hash</a><unsigned long long>; template<> struct <a class="link" href="../boost/hash_float_idp101633168.html" title="Struct hash<float>">hash</a><float>; template<> struct <a class="link" href="../boost/hash_double_idp37787440.html" title="Struct hash<double>">hash</a><double>; template<> struct <a class="link" href="../boost/hash_long_doub_idp40704560.html" title="Struct hash<long double>">hash</a><long double>; template<> struct <a class="link" href="../boost/hash_std_stri_idp110974848.html" title="Struct hash<std::string>">hash</a><std::string>; template<> struct <a class="link" href="../boost/hash_std_wstri_idp46340064.html" title="Struct hash<std::wstring>">hash</a><std::wstring>; template<typename T> struct <a class="link" href="../boost/hash_T_idp111201264.html" title="Struct template hash<T*>">hash</a><T*>; template<> struct <a class="link" href="../boost/hash_std_type__idp47603776.html" title="Struct hash<std::type_index>">hash</a><std::type_index>; // <a class="link" href="reference.html#idp105637376-bb">Support functions (Boost extension).</a> template<typename T> void <a class="link" href="reference.html#boost.hash_combine">hash_combine</a>(size_t &, T const&); template<typename It> std::size_t <a class="link" href="reference.html#idp49204992-bb">hash_range</a>(It, It); template<typename It> void <a class="link" href="reference.html#idp113433904-bb">hash_range</a>(std::size_t&, It, It); // <a class="link" href="reference.html#idp45574784-bb">Overloadable hash implementation (Boost extension).</a> std::size_t <a class="link" href="reference.html#idp54500624-bb">hash_value</a>(bool); std::size_t <a class="link" href="reference.html#idp54502368-bb">hash_value</a>(char); std::size_t <a class="link" href="reference.html#idp76377568-bb">hash_value</a>(signed char); std::size_t <a class="link" href="reference.html#idp76379312-bb">hash_value</a>(unsigned char); std::size_t <a class="link" href="reference.html#idp106951664-bb">hash_value</a>(wchar_t); std::size_t <a class="link" href="reference.html#idp106953408-bb">hash_value</a>(short); std::size_t <a class="link" href="reference.html#idp45628288-bb">hash_value</a>(unsigned short); std::size_t <a class="link" href="reference.html#idp45630032-bb">hash_value</a>(int); std::size_t <a class="link" href="reference.html#idp69078176-bb">hash_value</a>(unsigned int); std::size_t <a class="link" href="reference.html#idp69079920-bb">hash_value</a>(long); std::size_t <a class="link" href="reference.html#idp105511920-bb">hash_value</a>(unsigned long); std::size_t <a class="link" href="reference.html#idp105513664-bb">hash_value</a>(long long); std::size_t <a class="link" href="reference.html#idp100999280-bb">hash_value</a>(unsigned long long); std::size_t <a class="link" href="reference.html#idp101001024-bb">hash_value</a>(float); std::size_t <a class="link" href="reference.html#idp41306672-bb">hash_value</a>(double); std::size_t <a class="link" href="reference.html#idp41308416-bb">hash_value</a>(long double); template<typename T> std::size_t <a class="link" href="reference.html#idp55446864-bb">hash_value</a>(T* const&); template<typename T, unsigned N> std::size_t <a class="link" href="reference.html#idp55449296-bb">hash_value</a>(T (&val)[N]); template<typename T, unsigned N> std::size_t <a class="link" href="reference.html#idp96676912-bb">hash_value</a>(const T (&val)[N]); template<typename Ch, typename A> std::size_t <a class="link" href="reference.html#idp102539312-bb">hash_value</a>(std::basic_string<Ch, std::char_traits<Ch>, A> const&); template<typename A, typename B> std::size_t <a class="link" href="reference.html#idp50883840-bb">hash_value</a>(std::pair<A, B> const&); template<typename T, typename A> std::size_t <a class="link" href="reference.html#idp69660432-bb">hash_value</a>(std::vector<T, A> const&); template<typename T, typename A> std::size_t <a class="link" href="reference.html#idp76221008-bb">hash_value</a>(std::list<T, A> const&); template<typename T, typename A> std::size_t <a class="link" href="reference.html#idp110857472-bb">hash_value</a>(std::deque<T, A> const&); template<typename K, typename C, typename A> std::size_t <a class="link" href="reference.html#idp100168224-bb">hash_value</a>(std::set<K, C, A> const&); template<typename K, typename C, typename A> std::size_t <a class="link" href="reference.html#idp50842096-bb">hash_value</a>(std::multiset<K, C, A> const&); template<typename K, typename T, typename C, typename A> std::size_t <a class="link" href="reference.html#idp69145248-bb">hash_value</a>(std::map<K, T, C, A> const&); template<typename K, typename T, typename C, typename A> std::size_t <a class="link" href="reference.html#idp102727104-bb">hash_value</a>(std::multimap<K, T, C, A> const&); template<typename T> std::size_t <a class="link" href="reference.html#idp110658352-bb">hash_value</a>(std::complex<T> const&); std::size_t <a class="link" href="reference.html#idp110661104-bb">hash_value</a>(std::type_index); template<typename T, std::size_t N> std::size_t <a class="link" href="reference.html#idp47766112-bb">hash_value</a>(std::array<T, N> const&); template<typename... T> std::size_t <a class="link" href="reference.html#idp113415936-bb">hash_value</a>(std::tuple<T...>); }</pre> <div class="refsect2"> <a name="idp211880144"></a><h3> <a name="idp105637376-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">template<typename T> void <a name="boost.hash_combine"></a>hash_combine(size_t & seed, T const& v);</pre> Called repeatedly to incrementally create a hash value from several variables. <div class="variablelist"><table border="0" class="variablelist compact"> <colgroup> <col align="left" valign="top"> <col> </colgroup> <tbody> <tr> <td>Effects:</td> <td> Updates <code class="computeroutput">seed</code> with a new hash value generated by combining it with the result of <code class="computeroutput"><a class="link" href="reference.html#boost.hash_value_idp45575600">hash_value</a>(v)</code>. Will always produce the same result for the same combination of <code class="computeroutput">seed</code> and <code class="computeroutput"><a class="link" href="reference.html#boost.hash_value_idp45575600">hash_value</a>(v)</code> during the single run of a program. </td> </tr> <tr> <td>Notes:</td> <td> <a class="link" href="reference.html#boost.hash_value_idp45575600">hash_value</a> is called without qualification, so that overloads can be found via ADL. This is an extension to TR1 Forward declared in <code class="computeroutput"><boost/functional/hash_fwd.hpp></code> This hash function is not intended for general use, and isn't guaranteed to be equal during separate runs of a program - so please don't use it for any persistent storage or communication. </td> </tr> <tr> <td>Throws:</td> <td> Only throws if <a class="link" href="reference.html#boost.hash_value_idp45575600">hash_value</a>(T) throws. Strong exception safety, as long as <a class="link" href="reference.html#boost.hash_value_idp45575600">hash_value</a>(T) also has strong exception safety. </td> </tr> </tbody> </table></div> </li> <li class="listitem"> <a name="boost.hash_range"></a> <pre class="literallayout">template<typename It> std::size_t <a name="idp49204992-bb"></a>hash_range(It first, It last); template<typename It> void <a name="idp113433904-bb"></a>hash_range(std::size_t& seed, It first, It last);</pre> Calculate the combined hash value of the elements of an iterator range. <div class="variablelist"><table border="0" class="variablelist compact"> <colgroup> <col align="left" valign="top"> <col> </colgroup> <tbody> <tr> <td>Effects:</td> <td> For the two argument overload: <pre class="programlisting"> size_t seed = 0; for(; first != last; ++first) { <a class="link" href="reference.html#boost.hash_combine">hash_combine</a>(seed, *first); } return seed; </pre> For the three arguments overload: <pre class="programlisting"> for(; first != last; ++first) { <a class="link" href="reference.html#boost.hash_combine">hash_combine</a>(seed, *first); } </pre> </td> </tr> <tr> <td>Notes:</td> <td> <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. This is an extension to TR1 Forward declared in <code class="computeroutput"><boost/functional/hash_fwd.hpp></code> This hash function is not intended for general use, and isn't guaranteed to be equal during separate runs of a program - so please don't use it for any persistent storage or communication. </td> </tr> <tr> <td>Throws:</td> <td> Only throws if <code class="computeroutput"><a class="link" href="reference.html#boost.hash_value_idp45575600">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_idp45575600">hash_value</a>(std::iterator_traits<It>::value_type)</code> has basic exception safety. </td> </tr> </tbody> </table></div> </li> </ol></div> </div> <div class="refsect2"> <a name="idp211967120"></a><h3> <a name="idp45574784-bb"></a><code class="computeroutput"></code> Overloadable hash implementation (Boost extension).</h3> <div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"> <a name="boost.hash_value_idp45575600"></a> <pre class="literallayout">std::size_t <a name="idp54500624-bb"></a>hash_value(bool val); std::size_t <a name="idp54502368-bb"></a>hash_value(char val); std::size_t <a name="idp76377568-bb"></a>hash_value(signed char val); std::size_t <a name="idp76379312-bb"></a>hash_value(unsigned char val); std::size_t <a name="idp106951664-bb"></a>hash_value(wchar_t val); std::size_t <a name="idp106953408-bb"></a>hash_value(short val); std::size_t <a name="idp45628288-bb"></a>hash_value(unsigned short val); std::size_t <a name="idp45630032-bb"></a>hash_value(int val); std::size_t <a name="idp69078176-bb"></a>hash_value(unsigned int val); std::size_t <a name="idp69079920-bb"></a>hash_value(long val); std::size_t <a name="idp105511920-bb"></a>hash_value(unsigned long val); std::size_t <a name="idp105513664-bb"></a>hash_value(long long val); std::size_t <a name="idp100999280-bb"></a>hash_value(unsigned long long val); std::size_t <a name="idp101001024-bb"></a>hash_value(float val); std::size_t <a name="idp41306672-bb"></a>hash_value(double val); std::size_t <a name="idp41308416-bb"></a>hash_value(long double val); template<typename T> std::size_t <a name="idp55446864-bb"></a>hash_value(T* const& val); template<typename T, unsigned N> std::size_t <a name="idp55449296-bb"></a>hash_value(T (&val)[N]); template<typename T, unsigned N> std::size_t <a name="idp96676912-bb"></a>hash_value(const T (&val)[N]); template<typename Ch, typename A> std::size_t <a name="idp102539312-bb"></a>hash_value(std::basic_string<Ch, std::char_traits<Ch>, A> const& val); template<typename A, typename B> std::size_t <a name="idp50883840-bb"></a>hash_value(std::pair<A, B> const& val); template