{"id":184,"date":"2019-05-20T21:50:28","date_gmt":"2019-05-21T01:50:28","guid":{"rendered":"https:\/\/andybase.com\/?p=184"},"modified":"2019-05-21T08:20:46","modified_gmt":"2019-05-21T12:20:46","slug":"move","status":"publish","type":"post","link":"https:\/\/andybase.com\/?p=184","title":{"rendered":"std::move"},"content":{"rendered":"\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p>21\u5929\u662f\u80af\u5b9a\u6ca1\u6cd5\u5b66\u4f1aC++\u7684\u300222\u5929\u4e5f\u4e0d\u884c\u3002<\/p><\/blockquote>\n\n\n\n<p>C++11\u91cc\u5f15\u5165\u4e86\u4e00\u4e2a\u65b0\u7684\u6982\u5ff5 \uff1a<em>\u79fb\u52a8<\/em>\u3002 \u8fd9\u4e2a\u6982\u5ff5\u8bf4\u7b80\u5355\u5176\u5b9e\u5f88\u7b80\u5355\uff0c\u56e0\u4e3a\u5b83\u662f\u4ecb\u4e8e\u62f7\u8d1d\u548c\u5f15\u7528\u4e4b\u95f4\u7684\u4e00\u79cd\u6982\u5ff5\u3002\u4f46\u8fd8\u662f\u6709\u5f88\u591a\u5c0f\u4f19\u4f34\u8868\u793a\u4e0d\u7406\u89e3<em>\u79fb\u52a8<\/em>\u5230\u5e95\u505a\u4e86\u4ec0\u4e48\uff0c\u5982\u4f55\u7406\u89e3<em>\u79fb\u52a8<\/em>\u3002<\/p>\n\n\n\n<p>\u8981\u60f3\u7406\u89e3<em>\u79fb\u52a8<\/em>\uff0c\u5148\u6765\u4ecb\u7ecd\u4e00\u4e2a\u6982\u5ff5\uff1a\u5de6\u503c\u4e0e\u53f3\u503c\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">\u5de6\u503c\u4e0e\u53f3\u503c<\/h4>\n\n\n\n<p>\u7b3c\u7edf\u6765\u8bb2\uff0c\u5de6\u503c\u5c31\u662f\u80fd\u591f\u5bf9\u5176\u53d6\u5730\u5740\u7684\u503c\u3002\u53cd\u4e4b\u5c31\u662f\u53f3\u503c\uff08\u4e34\u65f6\u53d8\u91cf\u4e5f\u662f\u53f3\u503c\uff09\u3002\u6bd4\u5982<code>1<\/code>, <code>2.0<\/code>, <code>true<\/code>,  <code>nullptr<\/code>\u8fd9\u79cd\u7eaf\u503c\u7c7b\u578b\uff0c\u5c31\u662f\u59a5\u59a5\u7684\u53f3\u503c\u3002\u518d\u6bd4\u5982 <code>int a = 100;<\/code> \uff0c <code>a<\/code>\u662f\u5de6\u503c\uff0c<code>100<\/code>\u662f\u53f3\u503c\u3002\u5728\u7ed9<code>a<\/code>\u8d4b\u503c\u7684\u8fc7\u7a0b\u4e2d\uff0c\u6211\u4eec\u5c06<strong>\u53f3\u503c\u62f7\u8d1d\u5230\u4e86\u5de6\u503c<\/strong>\u3002\uff08\u5176\u5b9e\u5e76\u4e0d\u662f\u5b8c\u5168\u8fd9\u6837\uff0c\u7f16\u8bd1\u5668\u4f1a\u505a\u4e00\u5b9a\u7a0b\u5ea6\u7684\u4f18\u5316\uff0c\u4f46\u4e3a\u4e86\u65b9\u4fbf\u7406\u89e3\uff0c\u6211\u4eec\u4e0d\u8003\u8651\u7f16\u8bd1\u5668\u7684\u529f\u52b3\uff09<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">\u4e24\u4e2a\u6817\u5b50<\/h4>\n\n\n\n<p>\u5728\u65e9\u671fC++\u91cc\uff0c\u6211\u4eec\u901a\u5e38\u7528\u6307\u9488\u6216\u8005\u5f15\u7528\u6765\u4f20\u9012\u4e00\u4e2a<em>\u200c\u5927<\/em>\u53d8\u91cf\uff0c\u56e0\u4e3a\u53ef\u4ee5\u907f\u514d\u4e00\u6b21\u62f7\u8d1d\u7684\u5f00\u9500\u3002\u7b2c\u4e00\u4e2a\u6817\u5b50\uff1a<strong>\u5982\u679c\u6211\u4eec\u6709\u4e00\u4e2a\u6bd4\u8f83\u5927\u7684\u53f3\u503c\u53d8\u91cf\uff0c\u6211\u60f3\u5c06\u5b83\u4f20\u9012\u7ed9\u5176\u4ed6\u7684\u51fd\u6570\uff0c\u8be5\u5982\u4f55\u907f\u514d\/\u51cf\u5c11\u62f7\u8d1d\u7684\u5f00\u9500\u5462\uff1f<\/strong>\u6bd4\u8f83\u719f\u6089\u7684\u670b\u53cb\u53ef\u80fd\u4f1a\u8bf4\uff0c\u6211\u4eec\u53ef\u4ee5\u4f20\u9012 <code>const &amp;<\/code> \u6765\u907f\u514d\u62f7\u8d1d\u7684\u5f00\u9500\u3002<\/p>\n\n\n\n<p>\u6ca1\u9519\uff0c\u5728C++11 \u4e4b\u524d\uff0c<code>const &amp;<\/code> \u53ef\u4ee5\u5bf9\u53f3\u503c\u76f4\u63a5\u53d6\u5f15\u7528\u3002\u8fd9\u6837\u6211\u4eec\u53ef\u4ee5\u4f20\u9012\u5f15\u7528\u6765\u907f\u514d\u62f7\u8d1d\u7684\u5f00\u9500\u3002\u90a3\u4e48\u4e0b\u4e00\u4e2a\u6817\u5b50\u5c31\u662f\uff0c<strong>\u5982\u679c\u6211\u4eec\u6709\u4e00\u4e2a\u6bd4\u8f83\u5927\u7684\u53f3\u503c\u53d8\u91cf\uff0c\u6211\u60f3\u5c06\u5b83\u4f20\u9012\u7ed9\u5176\u4ed6\u7684\u51fd\u6570\uff0c<em>\u200c\u53c8\u60f3\u8981\u4fee\u6539\u8fd9\u4e2a\u53f3\u503c\u53d8\u91cf\u7684\u503c<\/em>\uff0c\u8be5\u5982\u4f55\u907f\u514d\/\u51cf\u5c11\u62f7\u8d1d\u7684\u5f00\u9500\u5462\uff1f<\/strong><\/p>\n\n\n\n<p>C++11 \u63d0\u51fa\u4e86\u4e00\u4e2a\u6982\u5ff5\uff1a\u53f3\u503c\u5f15\u7528\u3002\u8bed\u6cd5\u662f\u4e24\u4e2a&amp;\u3002 \u5b83\u5141\u8bb8\u6211\u4eec\u5bf9\u53f3\u503c\u8fdb\u884c\u76f4\u63a5\u5f15\u7528\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">\u79fb\u52a8<\/h4>\n\n\n\n<p>\u7406\u89e3\u4e86\u53f3\u503c\u4e4b\u540e\uff0c\u6211\u4eec\u6765\u601d\u8003\u4e00\u4e2a\u95ee\u9898\u3002\u5f53\u6211\u4eec\u8fdb\u884c\u8d4b\u503c\u8bed\u53e5\u65f6\uff0c\u5176\u5b9e\u662f\u6784\u5efa\u4e86\u4e00\u4e2a\u53f3\u503c\uff0c\u7136\u540e\u590d\u5236\u7ed9\u4e86\u5de6\u503c\u3002\u90a3\u4e48\u6709\u6ca1\u6709\u82b1\u9500\u66f4\u5c0f\u7684\u65b9\u6cd5\u5462\uff1f\u7b54\u6848\u5c31\u662f<em>\u79fb\u52a8<\/em>\u3002<\/p>\n\n\n\n<p>\u719f\u6089C++\u7684\u90fd\u77e5\u9053C++\u4e2d\u6709\u6784\u9020\u65b9\u6cd5\u3002\u6784\u9020\u65b9\u6cd5\u53c8\u6709<em>\u62f7\u8d1d\u6784\u9020<\/em>\u548c<em>\u8d4b\u503c\u6784\u9020<\/em>\u4e24\u79cd\u7279\u6b8a\u7684\u6784\u9020\u65b9\u6cd5\u3002C++11\u63d0\u51fa\u4e86\u65b0\u7684\u6784\u9020\u7c7b\u578b\uff1a<em>\u79fb\u52a8\u6784\u9020<\/em>\u3002\u4e5f\u5373\u65b9\u6cd5\u63a5\u53d7\u7684\u53c2\u6570\u662f\u4e00\u4e2a\u53f3\u503c\uff0c\u7136\u540e\u901a\u8fc7<em>\u79fb\u52a8<\/em>\u7684\u65b9\u5f0f\uff0c\u51cf\u5c11\u62f7\u8d1d\u4e0e\u9500\u6bc1\u7684\u5f00\u9500\uff0c\u5b9e\u73b0\u8d44\u6e90\u7684\u8f6c\u79fb\u3002\u6837\u5f0f\u4e3a\uff1a <code>Type::Type(Type &amp;&amp; rval)<\/code><\/p>\n\n\n\n<p>\u53e6\u4e00\u4e2a\u4f5c\u7528\u5c31\u662f\uff0c<code>std::move<\/code>\u5728\u79fb\u52a8\u7684\u65f6\u5019\uff0c<strong>\u53ef\u4ee5<\/strong> \u5265\u593a\u539f\u53d8\u91cf\u7684\u6570\u636e\u6240\u6709\u6743\u3002\u901a\u5e38\u8fdb\u884c\u6240\u6709\u6743\u8f6c\u79fb\u65f6\u6211\u4eec\u4f1a\u663e\u5f0f\u8c03\u7528<code>std::move<\/code> \u65b9\u6cd5\u3002<\/p>\n\n\n\n<p>\u4ee5<code>vector<\/code>\u6765\u4e3e\u4f8b\u3002 <\/p>\n\n\n\n<pre class=\"wp-block-syntaxhighlighter-code\">vector&lt;int> a {1,2,3,4,5};\nfor (auto i : a){\n    cout &lt;&lt; i&lt;&lt; \", \";   \/\/ --> 1, 2, 3, 4, 5   \n}\nvector&lt;int> b  = move(a);\n\nfor (auto i : a){\n    cout &lt;&lt; i&lt;&lt; endl;   \/\/ Nothing, moved to b\n}\ncout &lt;&lt; \"----\" &lt;&lt;endl;\nfor (auto i :b){\n    cout &lt;&lt; i&lt;&lt; \", \";   \/\/ --> 1, 2, 3, 4, 5   \n}<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\">\u8054\u901a<\/h4>\n\n\n\n<p>C++ 11 \u4e2d\u7684\u79fb\u52a8\u8bed\u4e49\u4f7f\u5f97\u6211\u4eec\u5728\u6784\u9020\u4e34\u65f6\u53d8\u91cf\uff0c\u51cf\u5c11\u6784\u9020\u4e0e\u6790\u6784\u7684\u6d88\u8017\uff0c\u5e76\u4e14\u53ef\u4ee5\u663e\u793a\u8868\u8fbe\u6240\u6709\u6743\u7684\u8f6c\u79fb\u3002\u65e2\u589e\u5f3a\u4e86\u4ee3\u7801\u7684\u8fd0\u884c\u6548\u7387\uff0c\u53c8\u589e\u52a0\u4e86\u4ee3\u7801\u7684\u53ef\u8bfb\u6027\u3002<\/p>\n\n\n\n<p>move\u4e0d\u4ea7\u751f\u65b0\u53d8\u91cf\uff0c\u5b83\u53ea\u662fc++\u7684\u642c\u8fd0\u5de5\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>21\u5929\u662f\u80af\u5b9a\u6ca1\u6cd5\u5b66\u4f1aC++\u7684\u300222\u5929\u4e5f\u4e0d\u884c\u3002 C++11\u91cc\u5f15\u5165\u4e86\u4e00\u4e2a\u65b0\u7684\u6982\u5ff5 \uff1a\u79fb\u52a8\u3002 \u8fd9\u4e2a\u6982\u5ff5\u8bf4\u7b80\u5355\u5176\u5b9e\u5f88\u7b80\u5355\uff0c\u56e0\u4e3a\u5b83\u662f\u4ecb\u4e8e\u62f7\u8d1d\u548c\u5f15\u7528\u4e4b\u95f4\u7684\u4e00\u79cd\u6982\u5ff5\u3002\u4f46\u8fd8\u662f\u6709\u5f88\u591a\u5c0f\u4f19\u4f34\u8868\u793a\u4e0d\u7406\u89e3\u79fb\u52a8\u5230\u5e95\u505a\u4e86\u4ec0\u4e48\uff0c\u5982\u4f55\u7406\u89e3\u79fb\u52a8\u3002 \u8981\u60f3\u7406\u89e3\u79fb\u52a8\uff0c\u5148\u6765\u4ecb\u7ecd\u4e00\u4e2a\u6982\u5ff5\uff1a\u5de6\u503c\u4e0e\u53f3\u503c\u3002 \u5de6\u503c\u4e0e\u53f3\u503c \u7b3c\u7edf\u6765\u8bb2\uff0c\u5de6\u503c\u5c31\u662f\u80fd\u591f\u5bf9\u5176\u53d6\u5730\u5740\u7684\u503c\u3002\u53cd\u4e4b\u5c31\u662f\u53f3\u503c\uff08\u4e34\u65f6\u53d8\u91cf\u4e5f\u662f\u53f3\u503c\uff09\u3002\u6bd4\u59821, 2.0, true, nullptr\u8fd9\u79cd\u7eaf\u503c\u7c7b\u578b\uff0c\u5c31\u662f\u59a5\u59a5\u7684\u53f3\u503c\u3002\u518d\u6bd4\u5982 int a = 100; \uff0c a\u662f\u5de6\u503c\uff0c100\u662f\u53f3\u503c\u3002\u5728\u7ed9a\u8d4b\u503c\u7684\u8fc7\u7a0b\u4e2d\uff0c\u6211\u4eec\u5c06\u53f3\u503c\u62f7\u8d1d\u5230\u4e86\u5de6\u503c\u3002\uff08\u5176\u5b9e\u5e76\u4e0d\u662f\u5b8c\u5168\u8fd9\u6837\uff0c\u7f16\u8bd1\u5668\u4f1a\u505a\u4e00\u5b9a\u7a0b\u5ea6\u7684\u4f18\u5316\uff0c\u4f46\u4e3a\u4e86\u65b9\u4fbf\u7406\u89e3\uff0c\u6211\u4eec\u4e0d\u8003\u8651\u7f16\u8bd1\u5668\u7684\u529f\u52b3\uff09 \u4e24\u4e2a\u6817\u5b50 \u5728\u65e9\u671fC++\u91cc\uff0c\u6211\u4eec\u901a\u5e38\u7528\u6307\u9488\u6216\u8005\u5f15\u7528\u6765\u4f20\u9012\u4e00\u4e2a\u200c\u5927\u53d8\u91cf\uff0c\u56e0\u4e3a\u53ef\u4ee5\u907f\u514d\u4e00\u6b21\u62f7\u8d1d\u7684\u5f00\u9500\u3002\u7b2c\u4e00\u4e2a\u6817\u5b50\uff1a\u5982\u679c\u6211\u4eec\u6709\u4e00\u4e2a\u6bd4\u8f83\u5927\u7684\u53f3\u503c\u53d8\u91cf\uff0c\u6211\u60f3\u5c06\u5b83\u4f20\u9012\u7ed9\u5176\u4ed6\u7684\u51fd\u6570\uff0c\u8be5\u5982\u4f55\u907f\u514d\/\u51cf\u5c11\u62f7\u8d1d\u7684\u5f00\u9500\u5462\uff1f\u6bd4\u8f83\u719f\u6089\u7684\u670b\u53cb\u53ef\u80fd\u4f1a\u8bf4\uff0c\u6211\u4eec\u53ef\u4ee5\u4f20\u9012 const &amp; [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center 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