{"id":104215,"date":"2026-09-12T02:48:59","date_gmt":"2026-09-11T18:48:59","guid":{"rendered":"https:\/\/www.wsisp.com\/helps\/104215.html"},"modified":"2026-09-12T02:48:59","modified_gmt":"2026-09-11T18:48:59","slug":"person-p2-personp%ef%bc%9b-%e7%9a%84-%e6%b2%a1%e6%9c%89%e8%b0%83%e7%94%a8%e7%94%a8%e6%88%b7%e8%87%aa%e5%ae%9a%e4%b9%89%e7%9a%84%e6%88%96%e8%80%85%e7%bc%96%e8%af%91%e5%99%a8%e9%bb%98%e8%ae%a4","status":"publish","type":"post","link":"https:\/\/www.wsisp.com\/helps\/104215.html","title":{"rendered":"Person p2 = Person(p)\uff1b \u7684 = \u6ca1\u6709\u8c03\u7528\u7528\u6237\u81ea\u5b9a\u4e49\u7684\u6216\u8005\u7f16\u8bd1\u5668\u9ed8\u8ba4\u751f\u6210\u7684 operator="},"content":{"rendered":"

class<\/span> Person<\/span>{<\/span>
\npublic<\/span>:<\/span>
\n Person<\/span>(<\/span>)<\/span>{<\/span>
\n cout <<<\/span> "no param contructor!"<\/span> <<<\/span> endl;<\/span>
\n mAge =<\/span> 10<\/span>;<\/span>
\n }<\/span>
\n Person<\/span>(<\/span>int<\/span> age)<\/span>{<\/span>
\n cout <<<\/span> "param constructor!"<\/span> <<<\/span> endl;<\/span>
\n mAge =<\/span> age;<\/span>
\n }<\/span>
\n Person<\/span>(<\/span>const<\/span> Person&<\/span> person)<\/span>{<\/span>
\n cout <<<\/span> "copy constructor!"<\/span> <<<\/span> endl;<\/span>
\n mAge =<\/span> person.<\/span>mAge;<\/span>
\n }<\/span>
\n ~<\/span>Person<\/span>(<\/span>)<\/span>{<\/span>
\n cout <<<\/span> "destructor!"<\/span> <<<\/span> endl;<\/span>
\n }<\/span>
\npublic<\/span>:<\/span>
\n int<\/span> mAge;<\/span>
\n}<\/span>;<\/span><\/p>\n

Person p2 = Person\u00a7;\u91cc\u7684\u8fd9\u4e2a=**\u6ca1\u6709\u8c03\u7528operator=`**\u2014\u2014\u4e0d\u7ba1\u662f\u7528\u6237\u81ea\u5b9a\u4e49\u7684\u8fd8\u662f\u7f16\u8bd1\u5668\u9ed8\u8ba4\u751f\u6210\u7684，\u90fd\u6ca1\u88ab\u7528\u5230\u3002<\/p>\n

\u5173\u952e\u533a\u522b：\u62f7\u8d1d\u521d\u59cb\u5316 vs \u8d4b\u503c<\/h3>\n

C++ \u91cc = \u5728\u4e24\u79cd\u4e0d\u540c\u573a\u5408\u542b\u4e49\u5b8c\u5168\u4e0d\u540c：<\/p>\n

\u573a\u5408\u4e00：\u5b9a\u4e49\u5bf9\u8c61\u7684\u540c\u65f6\u7528 = \u521d\u59cb\u5316（\u4f60\u8fd9\u884c\u4ee3\u7801\u5c31\u662f\u8fd9\u79cd）<\/p>\n

Person p2 =<\/span> Person<\/span>(<\/span>p)<\/span>;<\/span> \/\/ \u8fd9\u662f"\u62f7\u8d1d\u521d\u59cb\u5316"(copy-initialization)<\/span><\/p>\n

\u8fd9\u5176\u5b9e\u662f\u58f0\u660e\u8bed\u53e5\u7684\u4e00\u90e8\u5206，\u7b49\u4ef7\u5199\u6cd5\u662f Person p2(Person(p));\u3002\u7f16\u8bd1\u5668\u770b\u5230\u8fd9\u79cd\u5199\u6cd5，\u505a\u7684\u4e8b\u60c5\u662f\u9009\u62e9\u4e00\u4e2a\u6784\u9020\u51fd\u6570\u6765\u6784\u9020 p2，\u8ddf operator= \u6beb\u65e0\u5173\u7cfb\u3002<\/p>\n

\u573a\u5408\u4e8c：\u5bf9\u8c61\u5df2\u7ecf\u5b58\u5728，\u4e4b\u540e\u518d\u7528 =<\/p>\n

Person p2;<\/span> \/\/ \u5148\u7528\u9ed8\u8ba4\u6784\u9020\u51fd\u6570\u628a p2 \u6784\u9020\u51fa\u6765<\/span>
\np2 =<\/span> p;<\/span> \/\/ \u8fd9\u65f6\u5019\u624d\u662f\u771f\u6b63\u7684"\u8d4b\u503c"，\u8c03\u7528 operator=<\/span><\/p>\n

\u53ea\u6709\u8fd9\u79cd\u2014\u2014\u5bf9\u8c61\u5df2\u7ecf\u5b58\u5728，\u4f60\u518d\u5bf9\u5b83\u505a = xxx\u2014\u2014\u624d\u662f\u8c03\u7528\u8d4b\u503c\u8fd0\u7b97\u7b26\u3002<\/p>\n

Person p2 = Person(p); \u8fc7\u7a0b<\/h3>\n
  • Person(p)：\u663e\u5f0f\u8c03\u7528\u62f7\u8d1d\u6784\u9020\u51fd\u6570，\u7528 p \u6784\u9020\u51fa\u4e00\u4e2a\u4e34\u65f6\u5bf9\u8c61 \u2192 \u6253\u5370\u4e00\u6b21 "copy constructor!"<\/li>\n
  • \u8fd9\u4e2a\u4e34\u65f6\u5bf9\u8c61\u7528\u6765\u521d\u59cb\u5316 p2：\u56e0\u4e3a\u662f\u540c\u7c7b\u578b\u5bf9\u8c61\u7684\u62f7\u8d1d\u521d\u59cb\u5316，\u4ece C++17 \u5f00\u59cb\u8fd9\u4e00\u6b65\u662f\u5f3a\u5236\u62f7\u8d1d\u7701\u7565（guaranteed copy elision，C++17 \u4e4b\u524d\u591a\u6570\u7f16\u8bd1\u5668\u4e5f\u4f1a\u505a RVO \u4f18\u5316，\u53ea\u662f\u6807\u51c6\u4e0d\u5f3a\u5236），\u4e34\u65f6\u5bf9\u8c61\u76f4\u63a5"\u539f\u5730"\u6784\u9020\u6210 p2，\u4e0d\u4f1a\u518d\u989d\u5916\u8c03\u7528\u4e00\u6b21\u62f7\u8d1d\/\u79fb\u52a8\u6784\u9020\u51fd\u6570\u3002<\/li>\n

    \u6240\u4ee5\u5b9e\u9645\u8fd0\u884c\u4f60\u4f1a\u770b\u5230 p2 \u90a3\u4e00\u884c\u53ea\u6253\u5370\u4e00\u6b21 "copy constructor!"，\u800c\u4e0d\u662f\u4e24\u6b21\u3002<\/p>\n

    \u7f16\u8bd1\u5668\u751f\u6210\u7684\u9ed8\u8ba4 operator=<\/h3>\n

    Person \u7c7b\u786e\u5b9e\u4f1a\u88ab\u7f16\u8bd1\u5668\u9690\u5f0f\u751f\u6210\u4e00\u4e2a\u9ed8\u8ba4\u8d4b\u503c\u8fd0\u7b97\u7b26（\u56e0\u4e3a\u4f60\u6ca1\u6709\u81ea\u5df1\u5199，\u4e14\u6210\u5458\u53ea\u662f\u5185\u7f6e\u7c7b\u578b int，\u6ee1\u8db3\u751f\u6210\u6761\u4ef6）\u3002\u5b83\u957f\u8fd9\u6837（\u7f16\u8bd1\u5668\u5e2e\u4f60\u9690\u5f0f\u751f\u6210\u7684，\u9010\u6210\u5458\u62f7\u8d1d）：<\/p>\n

    Person&<\/span> operator<\/span>=<\/span>(<\/span>const<\/span> Person&<\/span> person)<\/span>{<\/span>
    \n mAge =<\/span> person.<\/span>mAge;<\/span>
    \n return<\/span> *<\/span>this<\/span>;<\/span>
    \n}<\/span><\/p>\n

    \u4f46\u8fd9\u4e2a\u51fd\u6570\u5728\u4f60\u8d34\u7684\u4ee3\u7801\u91cc\u4ece\u5934\u5230\u5c3e\u6ca1\u88ab\u8c03\u7528\u8fc7，\u56e0\u4e3a p1\u3001p2\u3001p3 \u5168\u90e8\u662f"\u5b9a\u4e49\u65f6\u521d\u59cb\u5316"，\u8d70\u7684\u90fd\u662f\u6784\u9020\u51fd\u6570（\u62f7\u8d1d\u6784\u9020）\u3002\u4f60\u60f3\u771f\u6b63\u770b\u5230\u5b83\u88ab\u8c03\u7528，\u5f97\u8fd9\u6837\u5199：<\/p>\n

    Person p4;<\/span> \/\/ \u5148\u6784\u9020<\/span>
    \np4 =<\/span> p;<\/span> \/\/ \u8fd9\u91cc\u624d\u4f1a\u6253\u5370\u4e00\u6b21 operator= \u91cc\u7684\u5185\u5bb9（\u5982\u679c\u4f60\u5728\u91cc\u9762\u52a0\u4e86 cout）<\/span><\/p>\n

    \u4e00\u53e5\u8bdd\u603b\u7ed3：\u5224\u65ad = \u662f\u521d\u59cb\u5316\u8fd8\u662f\u8d4b\u503c，\u770b\u5de6\u8fb9\u7684\u5bf9\u8c61\u6b64\u523b\u662f\u4e0d\u662f"\u521a\u521a\u88ab\u58f0\u660e\u3001\u7b2c\u4e00\u6b21\u62e5\u6709\u503c"\u2014\u2014\u662f\u7684\u8bdd\u5c31\u662f\u521d\u59cb\u5316（\u8c03\u7528\u6784\u9020\u51fd\u6570），\u4e0d\u662f\u7684\u8bdd（\u5bf9\u8c61\u65e9\u5c31\u5b58\u5728\u4e86）\u624d\u662f\u8d4b\u503c（\u8c03\u7528 operator=）\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"

    class Person{
    \npublic:Person(){cout << \\"no param contructor!\\" << endl;mAge 10;}Person(int age){cout << \\"param constructor!\\" << endl;mAge age;}Person(const Person& person){cout << \\"copy constructor!\\" << endl;mAge person.mAge;}~Person(){cou<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[55,190],"topic":[],"class_list":["post-104215","post","type-post","status-publish","format-standard","hentry","category-server","tag-c","tag-190"],"yoast_head":"\nPerson p2 = Person(p)\uff1b \u7684 = \u6ca1\u6709\u8c03\u7528\u7528\u6237\u81ea\u5b9a\u4e49\u7684\u6216\u8005\u7f16\u8bd1\u5668\u9ed8\u8ba4\u751f\u6210\u7684 operator= - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.wsisp.com\/helps\/104215.html\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Person p2 = Person(p)\uff1b \u7684 = \u6ca1\u6709\u8c03\u7528\u7528\u6237\u81ea\u5b9a\u4e49\u7684\u6216\u8005\u7f16\u8bd1\u5668\u9ed8\u8ba4\u751f\u6210\u7684 operator= - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\" \/>\n<meta property=\"og:description\" content=\"class Person{ public:Person(){cout << "no param contructor!" << endl;mAge 10;}Person(int age){cout << "param constructor!" << endl;mAge age;}Person(const Person& person){cout << "copy constructor!" << endl;mAge person.mAge;}~Person(){cou\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.wsisp.com\/helps\/104215.html\" \/>\n<meta property=\"og:site_name\" content=\"\u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\" \/>\n<meta property=\"article:published_time\" content=\"2026-09-11T18:48:59+00:00\" \/>\n<meta name=\"author\" content=\"admin\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u4f5c\u8005\" \/>\n\t<meta name=\"twitter:data1\" content=\"admin\" \/>\n\t<meta name=\"twitter:label2\" content=\"\u9884\u8ba1\u9605\u8bfb\u65f6\u95f4\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 \u5206\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.wsisp.com\/helps\/104215.html\",\"url\":\"https:\/\/www.wsisp.com\/helps\/104215.html\",\"name\":\"Person p2 = Person(p)\uff1b \u7684 = \u6ca1\u6709\u8c03\u7528\u7528\u6237\u81ea\u5b9a\u4e49\u7684\u6216\u8005\u7f16\u8bd1\u5668\u9ed8\u8ba4\u751f\u6210\u7684 operator= - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\",\"isPartOf\":{\"@id\":\"https:\/\/www.wsisp.com\/helps\/#website\"},\"datePublished\":\"2026-09-11T18:48:59+00:00\",\"dateModified\":\"2026-09-11T18:48:59+00:00\",\"author\":{\"@id\":\"https:\/\/www.wsisp.com\/helps\/#\/schema\/person\/358e386c577a3ab51c4493330a20ad41\"},\"breadcrumb\":{\"@id\":\"https:\/\/www.wsisp.com\/helps\/104215.html#breadcrumb\"},\"inLanguage\":\"zh-Hans\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.wsisp.com\/helps\/104215.html\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.wsisp.com\/helps\/104215.html#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"\u9996\u9875\",\"item\":\"https:\/\/www.wsisp.com\/helps\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Person p2 = Person(p)\uff1b \u7684 = \u6ca1\u6709\u8c03\u7528\u7528\u6237\u81ea\u5b9a\u4e49\u7684\u6216\u8005\u7f16\u8bd1\u5668\u9ed8\u8ba4\u751f\u6210\u7684 operator=\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.wsisp.com\/helps\/#website\",\"url\":\"https:\/\/www.wsisp.com\/helps\/\",\"name\":\"\u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\",\"description\":\"\u9999\u6e2f\u670d\u52a1\u5668_\u9999\u6e2f\u4e91\u670d\u52a1\u5668\u8d44\u8baf_\u670d\u52a1\u5668\u5e2e\u52a9\u6587\u6863_\u670d\u52a1\u5668\u6559\u7a0b\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.wsisp.com\/helps\/?s={search_term_string}\"},\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"zh-Hans\"},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.wsisp.com\/helps\/#\/schema\/person\/358e386c577a3ab51c4493330a20ad41\",\"name\":\"admin\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"zh-Hans\",\"@id\":\"https:\/\/www.wsisp.com\/helps\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/gravatar.wp-china-yes.net\/avatar\/?s=96&d=mystery\",\"contentUrl\":\"https:\/\/gravatar.wp-china-yes.net\/avatar\/?s=96&d=mystery\",\"caption\":\"admin\"},\"sameAs\":[\"http:\/\/wp.wsisp.com\"],\"url\":\"https:\/\/www.wsisp.com\/helps\/author\/admin\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Person p2 = Person(p)\uff1b \u7684 = \u6ca1\u6709\u8c03\u7528\u7528\u6237\u81ea\u5b9a\u4e49\u7684\u6216\u8005\u7f16\u8bd1\u5668\u9ed8\u8ba4\u751f\u6210\u7684 operator= - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.wsisp.com\/helps\/104215.html","og_locale":"zh_CN","og_type":"article","og_title":"Person p2 = Person(p)\uff1b \u7684 = \u6ca1\u6709\u8c03\u7528\u7528\u6237\u81ea\u5b9a\u4e49\u7684\u6216\u8005\u7f16\u8bd1\u5668\u9ed8\u8ba4\u751f\u6210\u7684 operator= - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3","og_description":"class Person{ public:Person(){cout << "no param contructor!" << endl;mAge 10;}Person(int age){cout << "param constructor!" << endl;mAge age;}Person(const Person& person){cout << "copy constructor!" << endl;mAge person.mAge;}~Person(){cou","og_url":"https:\/\/www.wsisp.com\/helps\/104215.html","og_site_name":"\u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3","article_published_time":"2026-09-11T18:48:59+00:00","author":"admin","twitter_card":"summary_large_image","twitter_misc":{"\u4f5c\u8005":"admin","\u9884\u8ba1\u9605\u8bfb\u65f6\u95f4":"1 \u5206"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/www.wsisp.com\/helps\/104215.html","url":"https:\/\/www.wsisp.com\/helps\/104215.html","name":"Person p2 = Person(p)\uff1b \u7684 = \u6ca1\u6709\u8c03\u7528\u7528\u6237\u81ea\u5b9a\u4e49\u7684\u6216\u8005\u7f16\u8bd1\u5668\u9ed8\u8ba4\u751f\u6210\u7684 operator= - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3","isPartOf":{"@id":"https:\/\/www.wsisp.com\/helps\/#website"},"datePublished":"2026-09-11T18:48:59+00:00","dateModified":"2026-09-11T18:48:59+00:00","author":{"@id":"https:\/\/www.wsisp.com\/helps\/#\/schema\/person\/358e386c577a3ab51c4493330a20ad41"},"breadcrumb":{"@id":"https:\/\/www.wsisp.com\/helps\/104215.html#breadcrumb"},"inLanguage":"zh-Hans","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.wsisp.com\/helps\/104215.html"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/www.wsisp.com\/helps\/104215.html#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"\u9996\u9875","item":"https:\/\/www.wsisp.com\/helps"},{"@type":"ListItem","position":2,"name":"Person p2 = Person(p)\uff1b \u7684 = \u6ca1\u6709\u8c03\u7528\u7528\u6237\u81ea\u5b9a\u4e49\u7684\u6216\u8005\u7f16\u8bd1\u5668\u9ed8\u8ba4\u751f\u6210\u7684 operator="}]},{"@type":"WebSite","@id":"https:\/\/www.wsisp.com\/helps\/#website","url":"https:\/\/www.wsisp.com\/helps\/","name":"\u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3","description":"\u9999\u6e2f\u670d\u52a1\u5668_\u9999\u6e2f\u4e91\u670d\u52a1\u5668\u8d44\u8baf_\u670d\u52a1\u5668\u5e2e\u52a9\u6587\u6863_\u670d\u52a1\u5668\u6559\u7a0b","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.wsisp.com\/helps\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"zh-Hans"},{"@type":"Person","@id":"https:\/\/www.wsisp.com\/helps\/#\/schema\/person\/358e386c577a3ab51c4493330a20ad41","name":"admin","image":{"@type":"ImageObject","inLanguage":"zh-Hans","@id":"https:\/\/www.wsisp.com\/helps\/#\/schema\/person\/image\/","url":"https:\/\/gravatar.wp-china-yes.net\/avatar\/?s=96&d=mystery","contentUrl":"https:\/\/gravatar.wp-china-yes.net\/avatar\/?s=96&d=mystery","caption":"admin"},"sameAs":["http:\/\/wp.wsisp.com"],"url":"https:\/\/www.wsisp.com\/helps\/author\/admin"}]}},"_links":{"self":[{"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/posts\/104215","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/comments?post=104215"}],"version-history":[{"count":0,"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/posts\/104215\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/media?parent=104215"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/categories?post=104215"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/tags?post=104215"},{"taxonomy":"topic","embeddable":true,"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/topic?post=104215"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}