<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta name="generator" content="rustdoc">
<meta name="description" content="Source to the Rust file `src/libstd/primitive_docs.rs`.">
<meta name="keywords" content="rust, rustlang, rust-lang">
<title>primitive_docs.rs.html -- source</title>
<link rel="stylesheet" type="text/css" href="../../normalize.css">
<link rel="stylesheet" type="text/css" href="../../rustdoc.css">
<link rel="stylesheet" type="text/css" href="../../main.css">
<link rel="shortcut icon" href="https://doc.rust-lang.org/favicon.ico">
</head>
<body class="rustdoc source">
<!--[if lte IE 8]>
<div class="warning">
This old browser is unsupported and will most likely display funky
things.
</div>
<![endif]-->
<nav class="sidebar">
<a href='../../std/index.html'><img src='https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png' alt='logo' width='100'></a>
</nav>
<nav class="sub">
<form class="search-form js-only">
<div class="search-container">
<input class="search-input" name="search"
autocomplete="off"
placeholder="Click or press ‘S’ to search, ‘?’ for more options…"
type="search">
</div>
</form>
</nav>
<section id='main' class="content"><pre class="line-numbers"><span id="1"> 1</span>
<span id="2"> 2</span>
<span id="3"> 3</span>
<span id="4"> 4</span>
<span id="5"> 5</span>
<span id="6"> 6</span>
<span id="7"> 7</span>
<span id="8"> 8</span>
<span id="9"> 9</span>
<span id="10"> 10</span>
<span id="11"> 11</span>
<span id="12"> 12</span>
<span id="13"> 13</span>
<span id="14"> 14</span>
<span id="15"> 15</span>
<span id="16"> 16</span>
<span id="17"> 17</span>
<span id="18"> 18</span>
<span id="19"> 19</span>
<span id="20"> 20</span>
<span id="21"> 21</span>
<span id="22"> 22</span>
<span id="23"> 23</span>
<span id="24"> 24</span>
<span id="25"> 25</span>
<span id="26"> 26</span>
<span id="27"> 27</span>
<span id="28"> 28</span>
<span id="29"> 29</span>
<span id="30"> 30</span>
<span id="31"> 31</span>
<span id="32"> 32</span>
<span id="33"> 33</span>
<span id="34"> 34</span>
<span id="35"> 35</span>
<span id="36"> 36</span>
<span id="37"> 37</span>
<span id="38"> 38</span>
<span id="39"> 39</span>
<span id="40"> 40</span>
<span id="41"> 41</span>
<span id="42"> 42</span>
<span id="43"> 43</span>
<span id="44"> 44</span>
<span id="45"> 45</span>
<span id="46"> 46</span>
<span id="47"> 47</span>
<span id="48"> 48</span>
<span id="49"> 49</span>
<span id="50"> 50</span>
<span id="51"> 51</span>
<span id="52"> 52</span>
<span id="53"> 53</span>
<span id="54"> 54</span>
<span id="55"> 55</span>
<span id="56"> 56</span>
<span id="57"> 57</span>
<span id="58"> 58</span>
<span id="59"> 59</span>
<span id="60"> 60</span>
<span id="61"> 61</span>
<span id="62"> 62</span>
<span id="63"> 63</span>
<span id="64"> 64</span>
<span id="65"> 65</span>
<span id="66"> 66</span>
<span id="67"> 67</span>
<span id="68"> 68</span>
<span id="69"> 69</span>
<span id="70"> 70</span>
<span id="71"> 71</span>
<span id="72"> 72</span>
<span id="73"> 73</span>
<span id="74"> 74</span>
<span id="75"> 75</span>
<span id="76"> 76</span>
<span id="77"> 77</span>
<span id="78"> 78</span>
<span id="79"> 79</span>
<span id="80"> 80</span>
<span id="81"> 81</span>
<span id="82"> 82</span>
<span id="83"> 83</span>
<span id="84"> 84</span>
<span id="85"> 85</span>
<span id="86"> 86</span>
<span id="87"> 87</span>
<span id="88"> 88</span>
<span id="89"> 89</span>
<span id="90"> 90</span>
<span id="91"> 91</span>
<span id="92"> 92</span>
<span id="93"> 93</span>
<span id="94"> 94</span>
<span id="95"> 95</span>
<span id="96"> 96</span>
<span id="97"> 97</span>
<span id="98"> 98</span>
<span id="99"> 99</span>
<span id="100">100</span>
<span id="101">101</span>
<span id="102">102</span>
<span id="103">103</span>
<span id="104">104</span>
<span id="105">105</span>
<span id="106">106</span>
<span id="107">107</span>
<span id="108">108</span>
<span id="109">109</span>
<span id="110">110</span>
<span id="111">111</span>
<span id="112">112</span>
<span id="113">113</span>
<span id="114">114</span>
<span id="115">115</span>
<span id="116">116</span>
<span id="117">117</span>
<span id="118">118</span>
<span id="119">119</span>
<span id="120">120</span>
<span id="121">121</span>
<span id="122">122</span>
<span id="123">123</span>
<span id="124">124</span>
<span id="125">125</span>
<span id="126">126</span>
<span id="127">127</span>
<span id="128">128</span>
<span id="129">129</span>
<span id="130">130</span>
<span id="131">131</span>
<span id="132">132</span>
<span id="133">133</span>
<span id="134">134</span>
<span id="135">135</span>
<span id="136">136</span>
<span id="137">137</span>
<span id="138">138</span>
<span id="139">139</span>
<span id="140">140</span>
<span id="141">141</span>
<span id="142">142</span>
<span id="143">143</span>
<span id="144">144</span>
<span id="145">145</span>
<span id="146">146</span>
<span id="147">147</span>
<span id="148">148</span>
<span id="149">149</span>
<span id="150">150</span>
<span id="151">151</span>
<span id="152">152</span>
<span id="153">153</span>
<span id="154">154</span>
<span id="155">155</span>
<span id="156">156</span>
<span id="157">157</span>
<span id="158">158</span>
<span id="159">159</span>
<span id="160">160</span>
<span id="161">161</span>
<span id="162">162</span>
<span id="163">163</span>
<span id="164">164</span>
<span id="165">165</span>
<span id="166">166</span>
<span id="167">167</span>
<span id="168">168</span>
<span id="169">169</span>
<span id="170">170</span>
<span id="171">171</span>
<span id="172">172</span>
<span id="173">173</span>
<span id="174">174</span>
<span id="175">175</span>
<span id="176">176</span>
<span id="177">177</span>
<span id="178">178</span>
<span id="179">179</span>
<span id="180">180</span>
<span id="181">181</span>
<span id="182">182</span>
<span id="183">183</span>
<span id="184">184</span>
<span id="185">185</span>
<span id="186">186</span>
<span id="187">187</span>
<span id="188">188</span>
<span id="189">189</span>
<span id="190">190</span>
<span id="191">191</span>
<span id="192">192</span>
<span id="193">193</span>
<span id="194">194</span>
<span id="195">195</span>
<span id="196">196</span>
<span id="197">197</span>
<span id="198">198</span>
<span id="199">199</span>
<span id="200">200</span>
<span id="201">201</span>
<span id="202">202</span>
<span id="203">203</span>
<span id="204">204</span>
<span id="205">205</span>
<span id="206">206</span>
<span id="207">207</span>
<span id="208">208</span>
<span id="209">209</span>
<span id="210">210</span>
<span id="211">211</span>
<span id="212">212</span>
<span id="213">213</span>
<span id="214">214</span>
<span id="215">215</span>
<span id="216">216</span>
<span id="217">217</span>
<span id="218">218</span>
<span id="219">219</span>
<span id="220">220</span>
<span id="221">221</span>
<span id="222">222</span>
<span id="223">223</span>
<span id="224">224</span>
<span id="225">225</span>
<span id="226">226</span>
<span id="227">227</span>
<span id="228">228</span>
<span id="229">229</span>
<span id="230">230</span>
<span id="231">231</span>
<span id="232">232</span>
<span id="233">233</span>
<span id="234">234</span>
<span id="235">235</span>
<span id="236">236</span>
<span id="237">237</span>
<span id="238">238</span>
<span id="239">239</span>
<span id="240">240</span>
<span id="241">241</span>
<span id="242">242</span>
<span id="243">243</span>
<span id="244">244</span>
<span id="245">245</span>
<span id="246">246</span>
<span id="247">247</span>
<span id="248">248</span>
<span id="249">249</span>
<span id="250">250</span>
<span id="251">251</span>
<span id="252">252</span>
<span id="253">253</span>
<span id="254">254</span>
<span id="255">255</span>
<span id="256">256</span>
<span id="257">257</span>
<span id="258">258</span>
<span id="259">259</span>
<span id="260">260</span>
<span id="261">261</span>
<span id="262">262</span>
<span id="263">263</span>
<span id="264">264</span>
<span id="265">265</span>
<span id="266">266</span>
<span id="267">267</span>
<span id="268">268</span>
<span id="269">269</span>
<span id="270">270</span>
<span id="271">271</span>
<span id="272">272</span>
<span id="273">273</span>
<span id="274">274</span>
<span id="275">275</span>
<span id="276">276</span>
<span id="277">277</span>
<span id="278">278</span>
<span id="279">279</span>
<span id="280">280</span>
<span id="281">281</span>
<span id="282">282</span>
<span id="283">283</span>
<span id="284">284</span>
<span id="285">285</span>
<span id="286">286</span>
<span id="287">287</span>
<span id="288">288</span>
<span id="289">289</span>
<span id="290">290</span>
<span id="291">291</span>
<span id="292">292</span>
<span id="293">293</span>
<span id="294">294</span>
<span id="295">295</span>
<span id="296">296</span>
<span id="297">297</span>
<span id="298">298</span>
<span id="299">299</span>
<span id="300">300</span>
<span id="301">301</span>
<span id="302">302</span>
<span id="303">303</span>
<span id="304">304</span>
<span id="305">305</span>
<span id="306">306</span>
<span id="307">307</span>
<span id="308">308</span>
<span id="309">309</span>
<span id="310">310</span>
<span id="311">311</span>
<span id="312">312</span>
<span id="313">313</span>
<span id="314">314</span>
<span id="315">315</span>
<span id="316">316</span>
<span id="317">317</span>
<span id="318">318</span>
<span id="319">319</span>
<span id="320">320</span>
<span id="321">321</span>
<span id="322">322</span>
<span id="323">323</span>
<span id="324">324</span>
<span id="325">325</span>
<span id="326">326</span>
<span id="327">327</span>
<span id="328">328</span>
<span id="329">329</span>
<span id="330">330</span>
<span id="331">331</span>
<span id="332">332</span>
<span id="333">333</span>
<span id="334">334</span>
<span id="335">335</span>
<span id="336">336</span>
<span id="337">337</span>
<span id="338">338</span>
<span id="339">339</span>
<span id="340">340</span>
<span id="341">341</span>
<span id="342">342</span>
<span id="343">343</span>
<span id="344">344</span>
<span id="345">345</span>
<span id="346">346</span>
<span id="347">347</span>
<span id="348">348</span>
<span id="349">349</span>
<span id="350">350</span>
<span id="351">351</span>
<span id="352">352</span>
<span id="353">353</span>
<span id="354">354</span>
<span id="355">355</span>
<span id="356">356</span>
<span id="357">357</span>
<span id="358">358</span>
<span id="359">359</span>
<span id="360">360</span>
<span id="361">361</span>
<span id="362">362</span>
<span id="363">363</span>
<span id="364">364</span>
<span id="365">365</span>
<span id="366">366</span>
<span id="367">367</span>
<span id="368">368</span>
<span id="369">369</span>
<span id="370">370</span>
<span id="371">371</span>
<span id="372">372</span>
<span id="373">373</span>
<span id="374">374</span>
<span id="375">375</span>
<span id="376">376</span>
<span id="377">377</span>
<span id="378">378</span>
<span id="379">379</span>
<span id="380">380</span>
<span id="381">381</span>
<span id="382">382</span>
<span id="383">383</span>
<span id="384">384</span>
<span id="385">385</span>
<span id="386">386</span>
<span id="387">387</span>
<span id="388">388</span>
<span id="389">389</span>
<span id="390">390</span>
<span id="391">391</span>
<span id="392">392</span>
<span id="393">393</span>
<span id="394">394</span>
<span id="395">395</span>
<span id="396">396</span>
<span id="397">397</span>
<span id="398">398</span>
<span id="399">399</span>
<span id="400">400</span>
<span id="401">401</span>
<span id="402">402</span>
<span id="403">403</span>
<span id="404">404</span>
<span id="405">405</span>
<span id="406">406</span>
<span id="407">407</span>
<span id="408">408</span>
<span id="409">409</span>
<span id="410">410</span>
<span id="411">411</span>
<span id="412">412</span>
<span id="413">413</span>
<span id="414">414</span>
<span id="415">415</span>
<span id="416">416</span>
<span id="417">417</span>
<span id="418">418</span>
<span id="419">419</span>
<span id="420">420</span>
<span id="421">421</span>
<span id="422">422</span>
<span id="423">423</span>
<span id="424">424</span>
<span id="425">425</span>
<span id="426">426</span>
<span id="427">427</span>
<span id="428">428</span>
<span id="429">429</span>
<span id="430">430</span>
<span id="431">431</span>
<span id="432">432</span>
<span id="433">433</span>
<span id="434">434</span>
<span id="435">435</span>
<span id="436">436</span>
<span id="437">437</span>
<span id="438">438</span>
<span id="439">439</span>
<span id="440">440</span>
<span id="441">441</span>
<span id="442">442</span>
<span id="443">443</span>
<span id="444">444</span>
<span id="445">445</span>
<span id="446">446</span>
<span id="447">447</span>
<span id="448">448</span>
<span id="449">449</span>
<span id="450">450</span>
<span id="451">451</span>
<span id="452">452</span>
<span id="453">453</span>
<span id="454">454</span>
<span id="455">455</span>
<span id="456">456</span>
<span id="457">457</span>
<span id="458">458</span>
<span id="459">459</span>
<span id="460">460</span>
<span id="461">461</span>
<span id="462">462</span>
<span id="463">463</span>
<span id="464">464</span>
<span id="465">465</span>
<span id="466">466</span>
<span id="467">467</span>
<span id="468">468</span>
<span id="469">469</span>
<span id="470">470</span>
<span id="471">471</span>
<span id="472">472</span>
<span id="473">473</span>
<span id="474">474</span>
<span id="475">475</span>
<span id="476">476</span>
<span id="477">477</span>
<span id="478">478</span>
<span id="479">479</span>
<span id="480">480</span>
<span id="481">481</span>
<span id="482">482</span>
<span id="483">483</span>
<span id="484">484</span>
<span id="485">485</span>
<span id="486">486</span>
<span id="487">487</span>
<span id="488">488</span>
<span id="489">489</span>
<span id="490">490</span>
<span id="491">491</span>
<span id="492">492</span>
<span id="493">493</span>
<span id="494">494</span>
<span id="495">495</span>
<span id="496">496</span>
<span id="497">497</span>
<span id="498">498</span>
<span id="499">499</span>
<span id="500">500</span>
<span id="501">501</span>
<span id="502">502</span>
<span id="503">503</span>
<span id="504">504</span>
<span id="505">505</span>
<span id="506">506</span>
<span id="507">507</span>
<span id="508">508</span>
<span id="509">509</span>
<span id="510">510</span>
<span id="511">511</span>
<span id="512">512</span>
<span id="513">513</span>
<span id="514">514</span>
<span id="515">515</span>
<span id="516">516</span>
<span id="517">517</span>
<span id="518">518</span>
<span id="519">519</span>
<span id="520">520</span>
<span id="521">521</span>
<span id="522">522</span>
<span id="523">523</span>
<span id="524">524</span>
<span id="525">525</span>
<span id="526">526</span>
<span id="527">527</span>
<span id="528">528</span>
<span id="529">529</span>
<span id="530">530</span>
<span id="531">531</span>
<span id="532">532</span>
<span id="533">533</span>
<span id="534">534</span>
<span id="535">535</span>
<span id="536">536</span>
<span id="537">537</span>
<span id="538">538</span>
<span id="539">539</span>
<span id="540">540</span>
<span id="541">541</span>
<span id="542">542</span>
<span id="543">543</span>
<span id="544">544</span>
<span id="545">545</span>
<span id="546">546</span>
<span id="547">547</span>
<span id="548">548</span>
<span id="549">549</span>
<span id="550">550</span>
<span id="551">551</span>
<span id="552">552</span>
<span id="553">553</span>
<span id="554">554</span>
<span id="555">555</span>
<span id="556">556</span>
<span id="557">557</span>
<span id="558">558</span>
<span id="559">559</span>
<span id="560">560</span>
<span id="561">561</span>
<span id="562">562</span>
<span id="563">563</span>
<span id="564">564</span>
<span id="565">565</span>
<span id="566">566</span>
<span id="567">567</span>
<span id="568">568</span>
<span id="569">569</span>
<span id="570">570</span>
<span id="571">571</span>
<span id="572">572</span>
<span id="573">573</span>
<span id="574">574</span>
<span id="575">575</span>
<span id="576">576</span>
<span id="577">577</span>
<span id="578">578</span>
<span id="579">579</span>
<span id="580">580</span>
<span id="581">581</span>
<span id="582">582</span>
<span id="583">583</span>
<span id="584">584</span>
<span id="585">585</span>
<span id="586">586</span>
<span id="587">587</span>
<span id="588">588</span>
<span id="589">589</span>
<span id="590">590</span>
<span id="591">591</span>
<span id="592">592</span>
<span id="593">593</span>
<span id="594">594</span>
<span id="595">595</span>
<span id="596">596</span>
<span id="597">597</span>
<span id="598">598</span>
<span id="599">599</span>
<span id="600">600</span>
<span id="601">601</span>
<span id="602">602</span>
<span id="603">603</span>
<span id="604">604</span>
<span id="605">605</span>
<span id="606">606</span>
<span id="607">607</span>
<span id="608">608</span>
<span id="609">609</span>
<span id="610">610</span>
<span id="611">611</span>
<span id="612">612</span>
<span id="613">613</span>
<span id="614">614</span>
<span id="615">615</span>
<span id="616">616</span>
<span id="617">617</span>
<span id="618">618</span>
<span id="619">619</span>
<span id="620">620</span>
<span id="621">621</span>
<span id="622">622</span>
<span id="623">623</span>
<span id="624">624</span>
<span id="625">625</span>
<span id="626">626</span>
<span id="627">627</span>
<span id="628">628</span>
<span id="629">629</span>
<span id="630">630</span>
<span id="631">631</span>
<span id="632">632</span>
<span id="633">633</span>
<span id="634">634</span>
<span id="635">635</span>
<span id="636">636</span>
<span id="637">637</span>
<span id="638">638</span>
<span id="639">639</span>
<span id="640">640</span>
<span id="641">641</span>
<span id="642">642</span>
<span id="643">643</span>
<span id="644">644</span>
<span id="645">645</span>
<span id="646">646</span>
<span id="647">647</span>
<span id="648">648</span>
<span id="649">649</span>
<span id="650">650</span>
<span id="651">651</span>
<span id="652">652</span>
<span id="653">653</span>
<span id="654">654</span>
<span id="655">655</span>
<span id="656">656</span>
<span id="657">657</span>
<span id="658">658</span>
<span id="659">659</span>
<span id="660">660</span>
<span id="661">661</span>
<span id="662">662</span>
<span id="663">663</span>
<span id="664">664</span>
<span id="665">665</span>
<span id="666">666</span>
<span id="667">667</span>
<span id="668">668</span>
<span id="669">669</span>
<span id="670">670</span>
<span id="671">671</span>
<span id="672">672</span>
<span id="673">673</span>
<span id="674">674</span>
<span id="675">675</span>
<span id="676">676</span>
<span id="677">677</span>
<span id="678">678</span>
<span id="679">679</span>
<span id="680">680</span>
<span id="681">681</span>
<span id="682">682</span>
<span id="683">683</span>
<span id="684">684</span>
<span id="685">685</span>
<span id="686">686</span>
<span id="687">687</span>
<span id="688">688</span>
<span id="689">689</span>
<span id="690">690</span>
<span id="691">691</span>
<span id="692">692</span>
<span id="693">693</span>
<span id="694">694</span>
<span id="695">695</span>
<span id="696">696</span>
<span id="697">697</span>
<span id="698">698</span>
<span id="699">699</span>
<span id="700">700</span>
<span id="701">701</span>
<span id="702">702</span>
<span id="703">703</span>
<span id="704">704</span>
<span id="705">705</span>
<span id="706">706</span>
<span id="707">707</span>
<span id="708">708</span>
<span id="709">709</span>
<span id="710">710</span>
<span id="711">711</span>
<span id="712">712</span>
<span id="713">713</span>
<span id="714">714</span>
<span id="715">715</span>
<span id="716">716</span>
<span id="717">717</span>
<span id="718">718</span>
<span id="719">719</span>
<span id="720">720</span>
<span id="721">721</span>
<span id="722">722</span>
</pre><pre class="rust ">
<span class="comment">// Copyright 2015 The Rust Project Developers. See the COPYRIGHT</span>
<span class="comment">// file at the top-level directory of this distribution and at</span>
<span class="comment">// http://rust-lang.org/COPYRIGHT.</span>
<span class="comment">//</span>
<span class="comment">// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or</span>
<span class="comment">// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license</span>
<span class="comment">// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your</span>
<span class="comment">// option. This file may not be copied, modified, or distributed</span>
<span class="comment">// except according to those terms.</span>
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"bool"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// The boolean type.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// The `bool` represents a value, which could only be either `true` or `false`. If you cast</span>
<span class="doccomment">/// a `bool` into an integer, `true` will be 1 and `false` will be 0.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Basic usage</span>
<span class="doccomment">///</span>
<span class="doccomment">/// `bool` implements various traits, such as [`BitAnd`], [`BitOr`], [`Not`], etc.,</span>
<span class="doccomment">/// which allow us to perform boolean operations using `&`, `|` and `!`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`if`] always demands a `bool` value. [`assert!`], being an important macro in testing,</span>
<span class="doccomment">/// checks whether an expression returns `true`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// let bool_val = true & false | false;</span>
<span class="doccomment">/// assert!(!bool_val);</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`assert!`]: macro.assert.html</span>
<span class="doccomment">/// [`if`]: ../book/first-edition/if.html</span>
<span class="doccomment">/// [`BitAnd`]: ops/trait.BitAnd.html</span>
<span class="doccomment">/// [`BitOr`]: ops/trait.BitOr.html</span>
<span class="doccomment">/// [`Not`]: ops/trait.Not.html</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// A trivial example of the usage of `bool`,</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// let praise_the_borrow_checker = true;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// // using the `if` conditional</span>
<span class="doccomment">/// if praise_the_borrow_checker {</span>
<span class="doccomment">/// println!("oh, yeah!");</span>
<span class="doccomment">/// } else {</span>
<span class="doccomment">/// println!("what?!!");</span>
<span class="doccomment">/// }</span>
<span class="doccomment">///</span>
<span class="doccomment">/// // ... or, a match pattern</span>
<span class="doccomment">/// match praise_the_borrow_checker {</span>
<span class="doccomment">/// true => println!("keep praising!"),</span>
<span class="doccomment">/// false => println!("you should praise!"),</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Also, since `bool` implements the [`Copy`](marker/trait.Copy.html) trait, we don't</span>
<span class="doccomment">/// have to worry about the move semantics (just like the integer and float primitives).</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Now an example of `bool` cast to integer type:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// assert_eq!(true as i32, 1);</span>
<span class="doccomment">/// assert_eq!(false as i32, 0);</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_bool</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"char"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// A character type.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// The `char` type represents a single character. More specifically, since</span>
<span class="doccomment">/// 'character' isn't a well-defined concept in Unicode, `char` is a '[Unicode</span>
<span class="doccomment">/// scalar value]', which is similar to, but not the same as, a '[Unicode code</span>
<span class="doccomment">/// point]'.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [Unicode scalar value]: http://www.unicode.org/glossary/#unicode_scalar_value</span>
<span class="doccomment">/// [Unicode code point]: http://www.unicode.org/glossary/#code_point</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This documentation describes a number of methods and trait implementations on the</span>
<span class="doccomment">/// `char` type. For technical reasons, there is additional, separate</span>
<span class="doccomment">/// documentation in [the `std::char` module](char/index.html) as well.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Representation</span>
<span class="doccomment">///</span>
<span class="doccomment">/// `char` is always four bytes in size. This is a different representation than</span>
<span class="doccomment">/// a given character would have as part of a [`String`]. For example:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// let v = vec!['h', 'e', 'l', 'l', 'o'];</span>
<span class="doccomment">///</span>
<span class="doccomment">/// // five elements times four bytes for each element</span>
<span class="doccomment">/// assert_eq!(20, v.len() * std::mem::size_of::<char>());</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let s = String::from("hello");</span>
<span class="doccomment">///</span>
<span class="doccomment">/// // five elements times one byte per element</span>
<span class="doccomment">/// assert_eq!(5, s.len() * std::mem::size_of::<u8>());</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`String`]: string/struct.String.html</span>
<span class="doccomment">///</span>
<span class="doccomment">/// As always, remember that a human intuition for 'character' may not map to</span>
<span class="doccomment">/// Unicode's definitions. For example, emoji symbols such as '❤️' can be more</span>
<span class="doccomment">/// than one Unicode code point; this ❤️ in particular is two:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// let s = String::from("❤️");</span>
<span class="doccomment">///</span>
<span class="doccomment">/// // we get two chars out of a single ❤️</span>
<span class="doccomment">/// let mut iter = s.chars();</span>
<span class="doccomment">/// assert_eq!(Some('\u{2764}'), iter.next());</span>
<span class="doccomment">/// assert_eq!(Some('\u{fe0f}'), iter.next());</span>
<span class="doccomment">/// assert_eq!(None, iter.next());</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This means it won't fit into a `char`. Trying to create a literal with</span>
<span class="doccomment">/// `let heart = '❤️';` gives an error:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```text</span>
<span class="doccomment">/// error: character literal may only contain one codepoint: '❤</span>
<span class="doccomment">/// let heart = '❤️';</span>
<span class="doccomment">/// ^~</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Another implication of the 4-byte fixed size of a `char` is that</span>
<span class="doccomment">/// per-`char` processing can end up using a lot more memory:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// let s = String::from("love: ❤️");</span>
<span class="doccomment">/// let v: Vec<char> = s.chars().collect();</span>
<span class="doccomment">///</span>
<span class="doccomment">/// assert_eq!(12, s.len() * std::mem::size_of::<u8>());</span>
<span class="doccomment">/// assert_eq!(32, v.len() * std::mem::size_of::<char>());</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_char</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"unit"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// The `()` type, sometimes called "unit" or "nil".</span>
<span class="doccomment">///</span>
<span class="doccomment">/// The `()` type has exactly one value `()`, and is used when there</span>
<span class="doccomment">/// is no other meaningful value that could be returned. `()` is most</span>
<span class="doccomment">/// commonly seen implicitly: functions without a `-> ...` implicitly</span>
<span class="doccomment">/// have return type `()`, that is, these are equivalent:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```rust</span>
<span class="doccomment">/// fn long() -> () {}</span>
<span class="doccomment">///</span>
<span class="doccomment">/// fn short() {}</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// The semicolon `;` can be used to discard the result of an</span>
<span class="doccomment">/// expression at the end of a block, making the expression (and thus</span>
<span class="doccomment">/// the block) evaluate to `()`. For example,</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```rust</span>
<span class="doccomment">/// fn returns_i64() -> i64 {</span>
<span class="doccomment">/// 1i64</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// fn returns_unit() {</span>
<span class="doccomment">/// 1i64;</span>
<span class="doccomment">/// }</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let is_i64 = {</span>
<span class="doccomment">/// returns_i64()</span>
<span class="doccomment">/// };</span>
<span class="doccomment">/// let is_unit = {</span>
<span class="doccomment">/// returns_i64();</span>
<span class="doccomment">/// };</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_unit</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"pointer"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// Raw, unsafe pointers, `*const T`, and `*mut T`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Working with raw pointers in Rust is uncommon,</span>
<span class="doccomment">/// typically limited to a few patterns.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Use the [`null`] function to create null pointers, and the [`is_null`] method</span>
<span class="doccomment">/// of the `*const T` type to check for null. The `*const T` type also defines</span>
<span class="doccomment">/// the [`offset`] method, for pointer math.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Common ways to create raw pointers</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ## 1. Coerce a reference (`&T`) or mutable reference (`&mut T`).</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// let my_num: i32 = 10;</span>
<span class="doccomment">/// let my_num_ptr: *const i32 = &my_num;</span>
<span class="doccomment">/// let mut my_speed: i32 = 88;</span>
<span class="doccomment">/// let my_speed_ptr: *mut i32 = &mut my_speed;</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// To get a pointer to a boxed value, dereference the box:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// let my_num: Box<i32> = Box::new(10);</span>
<span class="doccomment">/// let my_num_ptr: *const i32 = &*my_num;</span>
<span class="doccomment">/// let mut my_speed: Box<i32> = Box::new(88);</span>
<span class="doccomment">/// let my_speed_ptr: *mut i32 = &mut *my_speed;</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This does not take ownership of the original allocation</span>
<span class="doccomment">/// and requires no resource management later,</span>
<span class="doccomment">/// but you must not use the pointer after its lifetime.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ## 2. Consume a box (`Box<T>`).</span>
<span class="doccomment">///</span>
<span class="doccomment">/// The [`into_raw`] function consumes a box and returns</span>
<span class="doccomment">/// the raw pointer. It doesn't destroy `T` or deallocate any memory.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// let my_speed: Box<i32> = Box::new(88);</span>
<span class="doccomment">/// let my_speed: *mut i32 = Box::into_raw(my_speed);</span>
<span class="doccomment">///</span>
<span class="doccomment">/// // By taking ownership of the original `Box<T>` though</span>
<span class="doccomment">/// // we are obligated to put it together later to be destroyed.</span>
<span class="doccomment">/// unsafe {</span>
<span class="doccomment">/// drop(Box::from_raw(my_speed));</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Note that here the call to [`drop`] is for clarity - it indicates</span>
<span class="doccomment">/// that we are done with the given value and it should be destroyed.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ## 3. Get it from C.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// # #![feature(libc)]</span>
<span class="doccomment">/// extern crate libc;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// use std::mem;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// fn main() {</span>
<span class="doccomment">/// unsafe {</span>
<span class="doccomment">/// let my_num: *mut i32 = libc::malloc(mem::size_of::<i32>()) as *mut i32;</span>
<span class="doccomment">/// if my_num.is_null() {</span>
<span class="doccomment">/// panic!("failed to allocate memory");</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// libc::free(my_num as *mut libc::c_void);</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Usually you wouldn't literally use `malloc` and `free` from Rust,</span>
<span class="doccomment">/// but C APIs hand out a lot of pointers generally, so are a common source</span>
<span class="doccomment">/// of raw pointers in Rust.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// *[See also the `std::ptr` module](ptr/index.html).*</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`null`]: ../std/ptr/fn.null.html</span>
<span class="doccomment">/// [`is_null`]: ../std/primitive.pointer.html#method.is_null</span>
<span class="doccomment">/// [`offset`]: ../std/primitive.pointer.html#method.offset</span>
<span class="doccomment">/// [`into_raw`]: ../std/boxed/struct.Box.html#method.into_raw</span>
<span class="doccomment">/// [`drop`]: ../std/mem/fn.drop.html</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_pointer</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"array"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// A fixed-size array, denoted `[T; N]`, for the element type, `T`, and the</span>
<span class="doccomment">/// non-negative compile-time constant size, `N`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// There are two syntactic forms for creating an array:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// * A list with each element, i.e. `[x, y, z]`.</span>
<span class="doccomment">/// * A repeat expression `[x; N]`, which produces an array with `N` copies of `x`.</span>
<span class="doccomment">/// The type of `x` must be [`Copy`][copy].</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Arrays of sizes from 0 to 32 (inclusive) implement the following traits if</span>
<span class="doccomment">/// the element type allows it:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// - [`Clone`][clone] (only if `T: `[`Copy`][copy])</span>
<span class="doccomment">/// - [`Debug`][debug]</span>
<span class="doccomment">/// - [`IntoIterator`][intoiterator] (implemented for `&[T; N]` and `&mut [T; N]`)</span>
<span class="doccomment">/// - [`PartialEq`][partialeq], [`PartialOrd`][partialord], [`Eq`][eq], [`Ord`][ord]</span>
<span class="doccomment">/// - [`Hash`][hash]</span>
<span class="doccomment">/// - [`AsRef`][asref], [`AsMut`][asmut]</span>
<span class="doccomment">/// - [`Borrow`][borrow], [`BorrowMut`][borrowmut]</span>
<span class="doccomment">/// - [`Default`][default]</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This limitation on the size `N` exists because Rust does not yet support</span>
<span class="doccomment">/// code that is generic over the size of an array type. `[Foo; 3]` and `[Bar; 3]`</span>
<span class="doccomment">/// are instances of same generic type `[T; 3]`, but `[Foo; 3]` and `[Foo; 5]` are</span>
<span class="doccomment">/// entirely different types. As a stopgap, trait implementations are</span>
<span class="doccomment">/// statically generated up to size 32.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Arrays of *any* size are [`Copy`][copy] if the element type is [`Copy`][copy]. This</span>
<span class="doccomment">/// works because the [`Copy`][copy] trait is specially known to the compiler.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Arrays coerce to [slices (`[T]`)][slice], so a slice method may be called on</span>
<span class="doccomment">/// an array. Indeed, this provides most of the API for working with arrays.</span>
<span class="doccomment">/// Slices have a dynamic size and do not coerce to arrays.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// There is no way to move elements out of an array. See [`mem::replace`][replace]</span>
<span class="doccomment">/// for an alternative.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// let mut array: [i32; 3] = [0; 3];</span>
<span class="doccomment">///</span>
<span class="doccomment">/// array[1] = 1;</span>
<span class="doccomment">/// array[2] = 2;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// assert_eq!([1, 2], &array[1..]);</span>
<span class="doccomment">///</span>
<span class="doccomment">/// // This loop prints: 0 1 2</span>
<span class="doccomment">/// for x in &array {</span>
<span class="doccomment">/// print!("{} ", x);</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// An array itself is not iterable:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```ignore</span>
<span class="doccomment">/// let array: [i32; 3] = [0; 3];</span>
<span class="doccomment">///</span>
<span class="doccomment">/// for x in array { }</span>
<span class="doccomment">/// // error: the trait bound `[i32; 3]: std::iter::Iterator` is not satisfied</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// The solution is to coerce the array to a slice by calling a slice method:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// # let array: [i32; 3] = [0; 3];</span>
<span class="doccomment">/// for x in array.iter() { }</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// If the array has 32 or fewer elements (see above), you can also use the</span>
<span class="doccomment">/// array reference's [`IntoIterator`] implementation:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// # let array: [i32; 3] = [0; 3];</span>
<span class="doccomment">/// for x in &array { }</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [slice]: primitive.slice.html</span>
<span class="doccomment">/// [copy]: marker/trait.Copy.html</span>
<span class="doccomment">/// [clone]: clone/trait.Clone.html</span>
<span class="doccomment">/// [debug]: fmt/trait.Debug.html</span>
<span class="doccomment">/// [intoiterator]: iter/trait.IntoIterator.html</span>
<span class="doccomment">/// [partialeq]: cmp/trait.PartialEq.html</span>
<span class="doccomment">/// [partialord]: cmp/trait.PartialOrd.html</span>
<span class="doccomment">/// [eq]: cmp/trait.Eq.html</span>
<span class="doccomment">/// [ord]: cmp/trait.Ord.html</span>
<span class="doccomment">/// [hash]: hash/trait.Hash.html</span>
<span class="doccomment">/// [asref]: convert/trait.AsRef.html</span>
<span class="doccomment">/// [asmut]: convert/trait.AsMut.html</span>
<span class="doccomment">/// [borrow]: borrow/trait.Borrow.html</span>
<span class="doccomment">/// [borrowmut]: borrow/trait.BorrowMut.html</span>
<span class="doccomment">/// [default]: default/trait.Default.html</span>
<span class="doccomment">/// [replace]: mem/fn.replace.html</span>
<span class="doccomment">/// [`IntoIterator`]: iter/trait.IntoIterator.html</span>
<span class="doccomment">///</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_array</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"slice"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// A dynamically-sized view into a contiguous sequence, `[T]`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Slices are a view into a block of memory represented as a pointer and a</span>
<span class="doccomment">/// length.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// // slicing a Vec</span>
<span class="doccomment">/// let vec = vec![1, 2, 3];</span>
<span class="doccomment">/// let int_slice = &vec[..];</span>
<span class="doccomment">/// // coercing an array to a slice</span>
<span class="doccomment">/// let str_slice: &[&str] = &["one", "two", "three"];</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Slices are either mutable or shared. The shared slice type is `&[T]`,</span>
<span class="doccomment">/// while the mutable slice type is `&mut [T]`, where `T` represents the element</span>
<span class="doccomment">/// type. For example, you can mutate the block of memory that a mutable slice</span>
<span class="doccomment">/// points to:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// let x = &mut [1, 2, 3];</span>
<span class="doccomment">/// x[1] = 7;</span>
<span class="doccomment">/// assert_eq!(x, &[1, 7, 3]);</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// *[See also the `std::slice` module](slice/index.html).*</span>
<span class="doccomment">///</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_slice</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"str"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// String slices.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// The `str` type, also called a 'string slice', is the most primitive string</span>
<span class="doccomment">/// type. It is usually seen in its borrowed form, `&str`. It is also the type</span>
<span class="doccomment">/// of string literals, `&'static str`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Strings slices are always valid UTF-8.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This documentation describes a number of methods and trait implementations</span>
<span class="doccomment">/// on the `str` type. For technical reasons, there is additional, separate</span>
<span class="doccomment">/// documentation in the [`std::str`](str/index.html) module as well.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// String literals are string slices:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// let hello = "Hello, world!";</span>
<span class="doccomment">///</span>
<span class="doccomment">/// // with an explicit type annotation</span>
<span class="doccomment">/// let hello: &'static str = "Hello, world!";</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// They are `'static` because they're stored directly in the final binary, and</span>
<span class="doccomment">/// so will be valid for the `'static` duration.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Representation</span>
<span class="doccomment">///</span>
<span class="doccomment">/// A `&str` is made up of two components: a pointer to some bytes, and a</span>
<span class="doccomment">/// length. You can look at these with the [`as_ptr`] and [`len`] methods:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use std::slice;</span>
<span class="doccomment">/// use std::str;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let story = "Once upon a time...";</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let ptr = story.as_ptr();</span>
<span class="doccomment">/// let len = story.len();</span>
<span class="doccomment">///</span>
<span class="doccomment">/// // story has nineteen bytes</span>
<span class="doccomment">/// assert_eq!(19, len);</span>
<span class="doccomment">///</span>
<span class="doccomment">/// // We can re-build a str out of ptr and len. This is all unsafe because</span>
<span class="doccomment">/// // we are responsible for making sure the two components are valid:</span>
<span class="doccomment">/// let s = unsafe {</span>
<span class="doccomment">/// // First, we build a &[u8]...</span>
<span class="doccomment">/// let slice = slice::from_raw_parts(ptr, len);</span>
<span class="doccomment">///</span>
<span class="doccomment">/// // ... and then convert that slice into a string slice</span>
<span class="doccomment">/// str::from_utf8(slice)</span>
<span class="doccomment">/// };</span>
<span class="doccomment">///</span>
<span class="doccomment">/// assert_eq!(s, Ok(story));</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`as_ptr`]: #method.as_ptr</span>
<span class="doccomment">/// [`len`]: #method.len</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Note: This example shows the internals of `&str`. `unsafe` should not be</span>
<span class="doccomment">/// used to get a string slice under normal circumstances. Use `as_slice`</span>
<span class="doccomment">/// instead.</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_str</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"tuple"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// A finite heterogeneous sequence, `(T, U, ..)`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Let's cover each of those in turn:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Tuples are *finite*. In other words, a tuple has a length. Here's a tuple</span>
<span class="doccomment">/// of length `3`:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// ("hello", 5, 'c');</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// 'Length' is also sometimes called 'arity' here; each tuple of a different</span>
<span class="doccomment">/// length is a different, distinct type.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Tuples are *heterogeneous*. This means that each element of the tuple can</span>
<span class="doccomment">/// have a different type. In that tuple above, it has the type:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```rust,ignore</span>
<span class="doccomment">/// (&'static str, i32, char)</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Tuples are a *sequence*. This means that they can be accessed by position;</span>
<span class="doccomment">/// this is called 'tuple indexing', and it looks like this:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```rust</span>
<span class="doccomment">/// let tuple = ("hello", 5, 'c');</span>
<span class="doccomment">///</span>
<span class="doccomment">/// assert_eq!(tuple.0, "hello");</span>
<span class="doccomment">/// assert_eq!(tuple.1, 5);</span>
<span class="doccomment">/// assert_eq!(tuple.2, 'c');</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// For more about tuples, see [the book](../book/first-edition/primitive-types.html#tuples).</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Trait implementations</span>
<span class="doccomment">///</span>
<span class="doccomment">/// If every type inside a tuple implements one of the following traits, then a</span>
<span class="doccomment">/// tuple itself also implements it.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// * [`Clone`]</span>
<span class="doccomment">/// * [`Copy`]</span>
<span class="doccomment">/// * [`PartialEq`]</span>
<span class="doccomment">/// * [`Eq`]</span>
<span class="doccomment">/// * [`PartialOrd`]</span>
<span class="doccomment">/// * [`Ord`]</span>
<span class="doccomment">/// * [`Debug`]</span>
<span class="doccomment">/// * [`Default`]</span>
<span class="doccomment">/// * [`Hash`]</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`Clone`]: clone/trait.Clone.html</span>
<span class="doccomment">/// [`Copy`]: marker/trait.Copy.html</span>
<span class="doccomment">/// [`PartialEq`]: cmp/trait.PartialEq.html</span>
<span class="doccomment">/// [`Eq`]: cmp/trait.Eq.html</span>
<span class="doccomment">/// [`PartialOrd`]: cmp/trait.PartialOrd.html</span>
<span class="doccomment">/// [`Ord`]: cmp/trait.Ord.html</span>
<span class="doccomment">/// [`Debug`]: fmt/trait.Debug.html</span>
<span class="doccomment">/// [`Default`]: default/trait.Default.html</span>
<span class="doccomment">/// [`Hash`]: hash/trait.Hash.html</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Due to a temporary restriction in Rust's type system, these traits are only</span>
<span class="doccomment">/// implemented on tuples of arity 12 or less. In the future, this may change.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Basic usage:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// let tuple = ("hello", 5, 'c');</span>
<span class="doccomment">///</span>
<span class="doccomment">/// assert_eq!(tuple.0, "hello");</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Tuples are often used as a return type when you want to return more than</span>
<span class="doccomment">/// one value:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// fn calculate_point() -> (i32, i32) {</span>
<span class="doccomment">/// // Don't do a calculation, that's not the point of the example</span>
<span class="doccomment">/// (4, 5)</span>
<span class="doccomment">/// }</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let point = calculate_point();</span>
<span class="doccomment">///</span>
<span class="doccomment">/// assert_eq!(point.0, 4);</span>
<span class="doccomment">/// assert_eq!(point.1, 5);</span>
<span class="doccomment">///</span>
<span class="doccomment">/// // Combining this with patterns can be nicer.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let (x, y) = calculate_point();</span>
<span class="doccomment">///</span>
<span class="doccomment">/// assert_eq!(x, 4);</span>
<span class="doccomment">/// assert_eq!(y, 5);</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_tuple</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"f32"</span>)]</span>
<span class="doccomment">/// The 32-bit floating point type.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// *[See also the `std::f32` module](f32/index.html).*</span>
<span class="doccomment">///</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_f32</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"f64"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// The 64-bit floating point type.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// *[See also the `std::f64` module](f64/index.html).*</span>
<span class="doccomment">///</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_f64</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"i8"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// The 8-bit signed integer type.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// *[See also the `std::i8` module](i8/index.html).*</span>
<span class="doccomment">///</span>
<span class="doccomment">/// However, please note that examples are shared between primitive integer</span>
<span class="doccomment">/// types. So it's normal if you see usage of types like `i64` in there.</span>
<span class="doccomment">///</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_i8</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"i16"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// The 16-bit signed integer type.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// *[See also the `std::i16` module](i16/index.html).*</span>
<span class="doccomment">///</span>
<span class="doccomment">/// However, please note that examples are shared between primitive integer</span>
<span class="doccomment">/// types. So it's normal if you see usage of types like `i32` in there.</span>
<span class="doccomment">///</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_i16</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"i32"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// The 32-bit signed integer type.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// *[See also the `std::i32` module](i32/index.html).*</span>
<span class="doccomment">///</span>
<span class="doccomment">/// However, please note that examples are shared between primitive integer</span>
<span class="doccomment">/// types. So it's normal if you see usage of types like `i16` in there.</span>
<span class="doccomment">///</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_i32</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"i64"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// The 64-bit signed integer type.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// *[See also the `std::i64` module](i64/index.html).*</span>
<span class="doccomment">///</span>
<span class="doccomment">/// However, please note that examples are shared between primitive integer</span>
<span class="doccomment">/// types. So it's normal if you see usage of types like `i8` in there.</span>
<span class="doccomment">///</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_i64</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"i128"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// The 128-bit signed integer type.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// *[See also the `std::i128` module](i128/index.html).*</span>
<span class="doccomment">///</span>
<span class="doccomment">/// However, please note that examples are shared between primitive integer</span>
<span class="doccomment">/// types. So it's normal if you see usage of types like `i8` in there.</span>
<span class="doccomment">///</span>
<span class="attribute">#[<span class="ident">unstable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"i128"</span>, <span class="ident">issue</span><span class="op">=</span><span class="string">"35118"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_i128</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"u8"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// The 8-bit unsigned integer type.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// *[See also the `std::u8` module](u8/index.html).*</span>
<span class="doccomment">///</span>
<span class="doccomment">/// However, please note that examples are shared between primitive integer</span>
<span class="doccomment">/// types. So it's normal if you see usage of types like `u64` in there.</span>
<span class="doccomment">///</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_u8</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"u16"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// The 16-bit unsigned integer type.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// *[See also the `std::u16` module](u16/index.html).*</span>
<span class="doccomment">///</span>
<span class="doccomment">/// However, please note that examples are shared between primitive integer</span>
<span class="doccomment">/// types. So it's normal if you see usage of types like `u32` in there.</span>
<span class="doccomment">///</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_u16</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"u32"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// The 32-bit unsigned integer type.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// *[See also the `std::u32` module](u32/index.html).*</span>
<span class="doccomment">///</span>
<span class="doccomment">/// However, please note that examples are shared between primitive integer</span>
<span class="doccomment">/// types. So it's normal if you see usage of types like `u16` in there.</span>
<span class="doccomment">///</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_u32</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"u64"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// The 64-bit unsigned integer type.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// *[See also the `std::u64` module](u64/index.html).*</span>
<span class="doccomment">///</span>
<span class="doccomment">/// However, please note that examples are shared between primitive integer</span>
<span class="doccomment">/// types. So it's normal if you see usage of types like `u8` in there.</span>
<span class="doccomment">///</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_u64</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"u128"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// The 128-bit unsigned integer type.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// *[See also the `std::u128` module](u128/index.html).*</span>
<span class="doccomment">///</span>
<span class="doccomment">/// However, please note that examples are shared between primitive integer</span>
<span class="doccomment">/// types. So it's normal if you see usage of types like `u8` in there.</span>
<span class="doccomment">///</span>
<span class="attribute">#[<span class="ident">unstable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"i128"</span>, <span class="ident">issue</span><span class="op">=</span><span class="string">"35118"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_u128</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"isize"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// The pointer-sized signed integer type.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// *[See also the `std::isize` module](isize/index.html).*</span>
<span class="doccomment">///</span>
<span class="doccomment">/// However, please note that examples are shared between primitive integer</span>
<span class="doccomment">/// types. So it's normal if you see usage of types like `usize` in there.</span>
<span class="doccomment">///</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_isize</span> { }
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">primitive</span> <span class="op">=</span> <span class="string">"usize"</span>)]</span>
<span class="comment">//</span>
<span class="doccomment">/// The pointer-sized unsigned integer type.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// *[See also the `std::usize` module](usize/index.html).*</span>
<span class="doccomment">///</span>
<span class="doccomment">/// However, please note that examples are shared between primitive integer</span>
<span class="doccomment">/// types. So it's normal if you see usage of types like `isize` in there.</span>
<span class="doccomment">///</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">mod</span> <span class="ident">prim_usize</span> { }
</pre>
</section>
<section id='search' class="content hidden"></section>
<section class="footer"></section>
<aside id="help" class="hidden">
<div>
<h1 class="hidden">Help</h1>
<div class="shortcuts">
<h2>Keyboard Shortcuts</h2>
<dl>
<dt>?</dt>
<dd>Show this help dialog</dd>
<dt>S</dt>
<dd>Focus the search field</dd>
<dt>⇤</dt>
<dd>Move up in search results</dd>
<dt>⇥</dt>
<dd>Move down in search results</dd>
<dt>⏎</dt>
<dd>Go to active search result</dd>
<dt>+</dt>
<dd>Collapse/expand all sections</dd>
</dl>
</div>
<div class="infos">
<h2>Search Tricks</h2>
<p>
Prefix searches with a type followed by a colon (e.g.
<code>fn:</code>) to restrict the search to a given type.
</p>
<p>
Accepted types are: <code>fn</code>, <code>mod</code>,
<code>struct</code>, <code>enum</code>,
<code>trait</code>, <code>type</code>, <code>macro</code>,
and <code>const</code>.
</p>
<p>
Search functions by type signature (e.g.
<code>vec -> usize</code> or <code>* -> vec</code>)
</p>
</div>
</div>
</aside>
<script>
window.rootPath = "../../";
window.currentCrate = "std";
</script>
<script src="../../main.js"></script>
<script defer src="../../search-index.js"></script>
</body>
</html>
distrib
>
Mageia
>
6
>
x86_64
>
media
>
core-updates
>
by-pkgid
>
878cdd00a13d17a73c6619a777ef5d74
>
files
>
2750
