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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"><title>Quarks</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2"><link rel="start" href="index.html" title="GLib Reference Manual"><link rel="up" href="glib-data-types.html" title="GLib Data Types"><link rel="prev" href="glib-N-ary-Trees.html" title="N-ary Trees"><link rel="next" href="glib-Keyed-Data-Lists.html" title="Keyed Data Lists"><meta name="generator" content="GTK-Doc V1.9 (XML mode)"><link rel="stylesheet" href="style.css" type="text/css"><link rel="chapter" href="glib.html" title="GLib Overview"><link rel="chapter" href="glib-fundamentals.html" title="GLib Fundamentals"><link rel="chapter" href="glib-core.html" title="GLib Core Application Support"><link rel="chapter" href="glib-utilities.html" title="GLib Utilities"><link rel="chapter" href="glib-data-types.html" title="GLib Data Types"><link rel="chapter" href="tools.html" title="GLib Tools"><link rel="index" href="ix01.html" title="Index"><link rel="index" href="ix02.html" title="Index of deprecated symbols"><link rel="index" href="ix03.html" title="Index of new symbols in 2.2"><link rel="index" href="ix04.html" title="Index of new symbols in 2.4"><link rel="index" href="ix05.html" title="Index of new symbols in 2.6"><link rel="index" href="ix06.html" title="Index of new symbols in 2.8"><link rel="index" href="ix07.html" title="Index of new symbols in 2.10"><link rel="index" href="ix08.html" title="Index of new symbols in 2.12"><link rel="index" href="ix09.html" title="Index of new symbols in 2.14"><link rel="index" href="ix10.html" title="Index of new symbols in 2.16"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><table class="navigation" id="top" width="100%" summary="Navigation header" cellpadding="2" cellspacing="2"><tr valign="middle"><td><a accesskey="p" href="glib-N-ary-Trees.html"><img src="left.png" width="24" height="24" border="0" alt="Prev"></a></td><td><a accesskey="u" href="glib-data-types.html"><img src="up.png" width="24" height="24" border="0" alt="Up"></a></td><td><a accesskey="h" href="index.html"><img src="home.png" width="24" height="24" border="0" alt="Home"></a></td><th width="100%" align="center">GLib Reference Manual</th><td><a accesskey="n" href="glib-Keyed-Data-Lists.html"><img src="right.png" width="24" height="24" border="0" alt="Next"></a></td></tr><tr><td colspan="5" class="shortcuts"><nobr><a href="#id3350788" class="shortcut">Top</a>  |  <a href="#id3350944" class="shortcut">Description</a></nobr></td></tr></table><div class="refentry" lang="en"><a name="glib-Quarks"></a><div class="titlepage"></div><div class="refnamediv"><table width="100%"><tr><td valign="top"><h2><a name="id3350788"></a><span class="refentrytitle">Quarks</span></h2><p>Quarks — a 2-way association between a string and a unique integer identifier</p></td><td valign="top" align="right"></td></tr></table></div><div class="refsynopsisdiv"><h2>Synopsis</h2><pre class="synopsis">#include <glib.h>typedef <a class="link" href="glib-Quarks.html#GQuark">GQuark</a>;<a class="link" href="glib-Quarks.html#GQuark">GQuark</a> <a class="link" href="glib-Quarks.html#g-quark-from-string">g_quark_from_string</a> (const <a class="link" href="glib-Basic-Types.html#gchar">gchar</a> *string);<a class="link" href="glib-Quarks.html#GQuark">GQuark</a> <a class="link" href="glib-Quarks.html#g-quark-from-static-string">g_quark_from_static_string</a> (const <a class="link" href="glib-Basic-Types.html#gchar">gchar</a> *string);const <a class="link" href="glib-Basic-Types.html#gchar">gchar</a>* <a class="link" href="glib-Quarks.html#g-quark-to-string">g_quark_to_string</a> (<a class="link" href="glib-Quarks.html#GQuark">GQuark</a> quark);<a class="link" href="glib-Quarks.html#GQuark">GQuark</a> <a class="link" href="glib-Quarks.html#g-quark-try-string">g_quark_try_string</a> (const <a class="link" href="glib-Basic-Types.html#gchar">gchar</a> *string);const <a class="link" href="glib-Basic-Types.html#gchar">gchar</a>* <a class="link" href="glib-Quarks.html#g-intern-string">g_intern_string</a> (const <a class="link" href="glib-Basic-Types.html#gchar">gchar</a> *string);const <a class="link" href="glib-Basic-Types.html#gchar">gchar</a>* <a class="link" href="glib-Quarks.html#g-intern-static-string">g_intern_static_string</a> (const <a class="link" href="glib-Basic-Types.html#gchar">gchar</a> *string);</pre></div><div class="refsect1" lang="en"><a name="id3350944"></a><h2>Description</h2><p>Quarks are associations between strings and integer identifiers.Given either the string or the <a class="link" href="glib-Quarks.html#GQuark"><span class="type">GQuark</span></a> identifier it is possible toretrieve the other.</p><p>Quarks are used for bothDatasets andKeyed Data Lists.</p><p>To create a new quark from a string, use <a class="link" href="glib-Quarks.html#g-quark-from-string"><code class="function">g_quark_from_string()</code></a> or<a class="link" href="glib-Quarks.html#g-quark-from-static-string"><code class="function">g_quark_from_static_string()</code></a>.</p><p>To find the string corresponding to a given <a class="link" href="glib-Quarks.html#GQuark"><span class="type">GQuark</span></a>, use <a class="link" href="glib-Quarks.html#g-quark-to-string"><code class="function">g_quark_to_string()</code></a>.</p><p>To find the <a class="link" href="glib-Quarks.html#GQuark"><span class="type">GQuark</span></a> corresponding to a given string, use <a class="link" href="glib-Quarks.html#g-quark-try-string"><code class="function">g_quark_try_string()</code></a>.</p><p>Another use for the string pool maintained for the quark functions is stringinterning, using <a class="link" href="glib-Quarks.html#g-intern-string"><code class="function">g_intern_string()</code></a> or <a class="link" href="glib-Quarks.html#g-intern-static-string"><code class="function">g_intern_static_string()</code></a>. An interned string is a canonical representation for a string. One important advantage of interned strings is that they can be compared for equality by a simple pointer comparision, rather than using <code class="function">strcmp()</code>. </p></div><div class="refsect1" lang="en"><a name="id3351101"></a><h2>Details</h2><div class="refsect2" lang="en"><a name="id3351111"></a><h3><a name="GQuark"></a>GQuark</h3><a class="indexterm" name="id3351123"></a><pre class="programlisting">typedef guint32 GQuark;</pre><p>A GQuark is a non-zero integer which uniquely identifies a particular string.A GQuark value of zero is associated to <a class="link" href="glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>.</p></div><hr><div class="refsect2" lang="en"><a name="id3351150"></a><h3><a name="g-quark-from-string"></a>g_quark_from_string ()</h3><a class="indexterm" name="id3351163"></a><pre class="programlisting"><a class="link" href="glib-Quarks.html#GQuark">GQuark</a> g_quark_from_string (const <a class="link" href="glib-Basic-Types.html#gchar">gchar</a> *string);</pre><p>Gets the <a class="link" href="glib-Quarks.html#GQuark"><span class="type">GQuark</span></a> identifying the given string.If the string does not currently have an associated <a class="link" href="glib-Quarks.html#GQuark"><span class="type">GQuark</span></a>, a new<a class="link" href="glib-Quarks.html#GQuark"><span class="type">GQuark</span></a> is created, using a copy of the string.</p><div class="variablelist"><table border="0"><col align="left" valign="top"><tbody><tr><td><p><span class="term"><em class="parameter"><code>string</code></em> :</span></p></td><td>a string.</td></tr><tr><td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td><td>the <a class="link" href="glib-Quarks.html#GQuark"><span class="type">GQuark</span></a> identifying the string, or 0 if <em class="parameter"><code>string</code></em> is <a class="link" href="glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>.</td></tr></tbody></table></div></div><hr><div class="refsect2" lang="en"><a name="id3351270"></a><h3><a name="g-quark-from-static-string"></a>g_quark_from_static_string ()</h3><a class="indexterm" name="id3351284"></a><pre class="programlisting"><a class="link" href="glib-Quarks.html#GQuark">GQuark</a> g_quark_from_static_string (const <a class="link" href="glib-Basic-Types.html#gchar">gchar</a> *string);</pre><p>Gets the <a class="link" href="glib-Quarks.html#GQuark"><span class="type">GQuark</span></a> identifying the given (static) string.If the string does not currently have an associated <a class="link" href="glib-Quarks.html#GQuark"><span class="type">GQuark</span></a>, a new<a class="link" href="glib-Quarks.html#GQuark"><span class="type">GQuark</span></a> is created, linked to the given string.</p><p>Note that this function is identical to <a class="link" href="glib-Quarks.html#g-quark-from-string"><code class="function">g_quark_from_string()</code></a> exceptthat if a new <a class="link" href="glib-Quarks.html#GQuark"><span class="type">GQuark</span></a> is created the string itself is used rather thana copy. This saves memory, but can only be used if the string will<span class="emphasis"><em>always</em></span> exist. It can be used with statically⌨️ 快捷键说明
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