{"id":9503,"date":"2023-03-08T20:27:20","date_gmt":"2023-03-08T12:27:20","guid":{"rendered":"https:\/\/blog.iyatt.com\/?p=9503"},"modified":"2024-05-06T07:59:19","modified_gmt":"2024-05-05T23:59:19","slug":"c-lambda-%e8%a1%a8%e8%be%be%e5%bc%8f%e4%bd%bf%e7%94%a8","status":"publish","type":"post","link":"https:\/\/blog.iyatt.com\/?p=9503","title":{"rendered":"C++ Lambda \u8868\u8fbe\u5f0f\u4f7f\u7528"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_82_2 ez-toc-wrap-center counter-hierarchy ez-toc-counter ez-toc-light-blue ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title ez-toc-toggle\" style=\"cursor:pointer\">\u76ee\u5f55<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/blog.iyatt.com\/?p=9503\/#%E7%8E%AF%E5%A2%83\" >\u73af\u5883<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/blog.iyatt.com\/?p=9503\/#Lambda_%E8%A1%A8%E8%BE%BE%E5%BC%8F\" >Lambda \u8868\u8fbe\u5f0f<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/blog.iyatt.com\/?p=9503\/#%E7%94%A8%E4%BD%9C%E5%87%BD%E6%95%B0%E5%AF%B9%E8%B1%A1\" >\u7528\u4f5c\u51fd\u6570\u5bf9\u8c61<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/blog.iyatt.com\/?p=9503\/#%E7%94%A8%E4%BD%9C%E8%BF%94%E5%9B%9E%E5%80%BC\" >\u7528\u4f5c\u8fd4\u56de\u503c<\/a><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"%E7%8E%AF%E5%A2%83\"><\/span>\u73af\u5883<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Debian 11\uff08arm64\uff09<\/p>\n<p>\u7f16\u8bd1\u5668 g++ 10.2.1\uff1b\u7f16\u8bd1\u6807\u51c6 C++20\uff1b\u53c2\u6570\uff1a-std=c++20 -no-pie -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Werror=format-security -Wextra -pedantic -Wimplicit-fallthrough -Wsequence-point -Wswitch-unreachable -Wswitch-enum -Wstringop-truncation -Wbool-compare -Wtautological-compare -Wfloat-equal -Wshadow=global -Wpointer-arith -Wpointer-compare -Wcast-align -Wcast-qual -Wwrite-strings -Wdangling-else -Wlogical-op -Wconversion -g -O0<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Lambda_%E8%A1%A8%E8%BE%BE%E5%BC%8F\"><\/span>Lambda \u8868\u8fbe\u5f0f<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Lambda \u8868\u8fbe\u5f0f\u53ef\u7528\u4e8e\u521b\u5efa\u533f\u540d\u51fd\u6570\u5bf9\u8c61<\/p>\n<p>\u57fa\u672c\u8bed\u6cd5<\/p>\n<pre><code>[\u6355\u83b7\u5217\u8868](\u53c2\u6570\u5217\u8868)-&gt;\u8fd4\u56de\u503c{\u51fd\u6570\u4f53}<\/code><\/pre>\n<ul>\n<li>\u6355\u83b7\u5217\u8868\u7528\u4e8e\u8bbf\u95ee\u5916\u90e8\u53d8\u91cf<\/li>\n<li>\u53c2\u6570\u5217\u8868\u7528\u4e8e\u6307\u5b9a\u53c2\u6570\uff0cC++14 \u5f00\u59cb\u53c2\u6570\u7c7b\u578b\u53ef\u4ee5\u4f7f\u7528 auto\uff0c\u7531\u7f16\u8bd1\u5668\u81ea\u52a8\u63a8\u5bfc\uff08\u6cdb\u578b\uff09<\/li>\n<li>\u8fd4\u56de\u503c\u6307\u5b9a\u8fd4\u56de\u503c\u7c7b\u578b\uff0c\u53ef\u4ee5\u7701\u7565\u7531\u7f16\u8bd1\u5668\u81ea\u52a8\u63a8\u5bfc<\/li>\n<li>\u51fd\u6570\u4f53\u8fdb\u884c\u529f\u80fd\u5b9e\u73b0<\/li>\n<\/ul>\n<pre><code class=\"language-cpp\">#include &lt;iostream&gt;\n\nint main()\n{\n    \/\/ \u6307\u660e\u4e86\u53c2\u6570\u5217\u8868\u7c7b\u578b\u548c\u8fd4\u56de\u503c\u7c7b\u578b\n    auto f1 = [](int num1, int num2)-&gt;int{return num1 + num2;};\n    std::cout &lt;&lt; f1(2, 8) &lt;&lt; std::endl;\n\n    \/\/ \u81ea\u52a8\u63a8\u5bfc\u53c2\u6570\u5217\u8868\u7c7b\u578b\uff08\u6cdb\u578b\uff09\u548c\u8fd4\u56de\u503c\u7c7b\u578b\n    auto f2 = [](auto num1, auto num2){return num1 + num2;};\n    std::cout &lt;&lt; f2(2, 8) &lt;&lt; std::endl;\n    std::cout &lt;&lt; f2(4.8, 3.2) &lt;&lt; std::endl;\n\n    \/\/ \u6355\u83b7\u5217\u8868\u7684\u4f7f\u7528\n    int x = 10;\n    int y = 5;\n    auto f3 = [x, y](auto num1, auto num2){return (num1 + num2) * x * y;};\n    std::cout &lt;&lt; f3(2, 8) &lt;&lt; std::endl;\n}<\/code><\/pre>\n<p><img decoding=\"async\" data-src=\"https:\/\/blog.iyatt.com\/wp-content\/uploads\/2023\/03\/image-1678274675342.png\" alt=\"file\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" class=\"lazyload\" style=\"--smush-placeholder-width: 153px; --smush-placeholder-aspect-ratio: 153\/146;\" \/><\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E7%94%A8%E4%BD%9C%E5%87%BD%E6%95%B0%E5%AF%B9%E8%B1%A1\"><\/span>\u7528\u4f5c\u51fd\u6570\u5bf9\u8c61<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Lambda \u53ef\u4ee5\u4f20\u7ed9\u51fd\u6570\u6216\u7b97\u6cd5\uff0c\u4f5c\u7528\u7c7b\u4f3c\u51fd\u6570\u5bf9\u8c61<\/p>\n<pre><code class=\"language-cpp\">#include &lt;iostream&gt;\n#include &lt;vector&gt;\n#include &lt;algorithm&gt;\n\nclass Even\n{\n    public:\n        bool operator()(int n)\n        {\n            return n % 2 == 0;\n        }\n};\n\nint main()\n{\n    std::vector nums {1, 6, 4, 7, 9, 3, 8};\n\n    \/\/ \u51fd\u6570\u5bf9\u8c61\n    auto count = std::count_if(nums.begin(), nums.end(), Even());\n    std::cout &lt;&lt; count &lt;&lt; std::endl;\n\n    \/\/ Lambda\n    auto even = [](auto n){return n % 2 == 0;};\n    count = std::count_if(nums.begin(), nums.end(), even);\n    std::cout &lt;&lt; count &lt;&lt; std::endl;\n}<\/code><\/pre>\n<p><img decoding=\"async\" data-src=\"https:\/\/blog.iyatt.com\/wp-content\/uploads\/2023\/03\/image-1678277582830.png\" alt=\"file\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" class=\"lazyload\" style=\"--smush-placeholder-width: 112px; --smush-placeholder-aspect-ratio: 112\/109;\" \/><\/p>\n<h3><span class=\"ez-toc-section\" id=\"%E7%94%A8%E4%BD%9C%E8%BF%94%E5%9B%9E%E5%80%BC\"><\/span>\u7528\u4f5c\u8fd4\u56de\u503c<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<pre><code class=\"language-cpp\">#include &lt;iostream&gt;\n#include &lt;functional&gt;\n\n\/\/ \u51fd\u6570\u9002\u914d\u5668\nstd::function&lt;int(int)&gt; f(int num1, int num2)\n{\n    return [num1, num2](int n){return (num1 + num2) * n;};\n}\n\nint main()\n{\n    auto f1 = f(4, 5);\n    std::cout &lt;&lt; f1(3) &lt;&lt; std::endl; \/\/ (4 + 5) * 3\n\n    auto f2 = f(1, 2);\n    std::cout &lt;&lt; f2(5) &lt;&lt; std::endl; \/\/ (1 + 2) * 5\n}<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>\u73af\u5883 Debian 11\uff08arm64\uff09 \u7f16\u8bd1\u5668 g++ 10.2.1\uff1b\u7f16\u8bd1\u6807\u51c6 C++20\uff1b\u53c2\u6570\uff1a-std=c [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"zakra_page_container_layout":"customizer","zakra_page_sidebar_layout":"customizer","zakra_remove_content_margin":false,"zakra_sidebar":"customizer","zakra_transparent_header":"customizer","zakra_logo":0,"zakra_main_header_style":"default","zakra_menu_item_color":"","zakra_menu_item_hover_color":"","zakra_menu_item_active_color":"","zakra_menu_active_style":"","zakra_page_header":true,"_lmt_disableupdate":"","_lmt_disable":"","footnotes":""},"categories":[1,589],"tags":[],"class_list":["post-9503","post","type-post","status-publish","format-standard","hentry","category-all","category-c-c"],"modified_by":"IYATT-yx","_links":{"self":[{"href":"https:\/\/blog.iyatt.com\/index.php?rest_route=\/wp\/v2\/posts\/9503","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.iyatt.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.iyatt.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.iyatt.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.iyatt.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=9503"}],"version-history":[{"count":0,"href":"https:\/\/blog.iyatt.com\/index.php?rest_route=\/wp\/v2\/posts\/9503\/revisions"}],"wp:attachment":[{"href":"https:\/\/blog.iyatt.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=9503"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.iyatt.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=9503"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.iyatt.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=9503"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}