{"id":39,"date":"2021-05-22T16:26:51","date_gmt":"2021-05-22T08:26:51","guid":{"rendered":"https:\/\/blog.cauchyschwarz.com\/?p=39"},"modified":"2021-05-27T00:41:37","modified_gmt":"2021-05-26T16:41:37","slug":"%e6%b7%b1%e5%85%a5%e5%ba%94%e7%94%a8c11%e7%ac%94%e8%ae%b0-%e7%ac%ac7%e7%ab%a0","status":"publish","type":"post","link":"https:\/\/blog.cauchyschwarz.com\/?p=39","title":{"rendered":"\u6df1\u5165\u5e94\u7528C++11\u7b14\u8bb0 \u7b2c7\u7ae0"},"content":{"rendered":"\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_84 ez-toc-wrap-right counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<label for=\"ez-toc-cssicon-toggle-item-6a2a4d0da2a7b\" class=\"ez-toc-cssicon-toggle-label\"><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\" 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href=\"https:\/\/blog.cauchyschwarz.com\/?p=39\/#C11%E7%9A%84%E5%85%B6%E4%BB%96%E7%89%B9%E6%80%A7\" >C++11\u7684\u5176\u4ed6\u7279\u6027<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=39\/#%E5%A7%94%E6%89%98%E6%9E%84%E9%80%A0%E5%87%BD%E6%95%B0%E5%92%8C%E7%BB%A7%E6%89%BF%E6%9E%84%E9%80%A0%E5%87%BD%E6%95%B0\" >\u59d4\u6258\u6784\u9020\u51fd\u6570\u548c\u7ee7\u627f\u6784\u9020\u51fd\u6570<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=39\/#%E5%8E%9F%E5%A7%8B%E5%AD%97%E9%9D%A2%E9%87%8F\" >\u539f\u59cb\u5b57\u9762\u91cf<\/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.cauchyschwarz.com\/?p=39\/#final%E5%92%8Coverride%E6%A0%87%E8%AF%86%E7%AC%A6\" >final\u548coverride\u6807\u8bc6\u7b26<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=39\/#%E5%86%85%E5%AD%98%E5%AF%B9%E9%BD%90\" >\u5185\u5b58\u5bf9\u9f50<\/a><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=39\/#%E4%B8%BA%E4%BB%80%E4%B9%88%E6%9C%89%E5%86%85%E5%AD%98%E5%AF%B9%E9%BD%90\" >\u4e3a\u4ec0\u4e48\u6709\u5185\u5b58\u5bf9\u9f50<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=39\/#%E5%86%85%E5%AD%98%E5%AF%B9%E9%BD%90%E5%85%B7%E4%BD%93%E8%A6%81%E6%B1%82\" >\u5185\u5b58\u5bf9\u9f50\u5177\u4f53\u8981\u6c42<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=39\/#%E8%B8%A9%E8%BF%87%E5%86%85%E5%AD%98%E5%AF%B9%E9%BD%90%E7%9A%84%E5%93%AA%E4%BA%9B%E5%9D%91\" >\u8e29\u8fc7\u5185\u5b58\u5bf9\u9f50\u7684\u54ea\u4e9b\u5751<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=39\/#%E7%90%86%E8%A7%A3%E4%BA%86%E5%86%85%E5%AD%98%E5%AF%B9%E9%BD%90%E5%90%8E%E5%8F%AF%E4%BB%A5%E6%80%8E%E6%A0%B7%E6%8A%8A%E7%A8%8B%E5%BA%8F%E5%86%99%E7%9A%84%E6%9B%B4%E5%A5%BD\" >\u7406\u89e3\u4e86\u5185\u5b58\u5bf9\u9f50\u540e\u53ef\u4ee5\u600e\u6837\u628a\u7a0b\u5e8f\u5199\u7684\u66f4\u597d<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=39\/#malloc%E4%B8%8E%E5%86%85%E5%AD%98%E5%AF%B9%E9%BD%90\" >malloc\u4e0e\u5185\u5b58\u5bf9\u9f50<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=39\/#c11%E4%B8%AD%E6%8F%90%E4%BE%9B%E7%9A%84%E5%86%85%E5%AD%98%E5%AF%B9%E9%BD%90%E7%9B%B8%E5%85%B3%E5%B7%A5%E5%85%B7\" >c++11\u4e2d\u63d0\u4f9b\u7684\u5185\u5b58\u5bf9\u9f50\u76f8\u5173\u5de5\u5177<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=39\/#C11%E6%96%B0%E5%A2%9E%E7%9A%84%E4%BE%BF%E5%88%A9%E7%AE%97%E6%B3%95\" >C++11\u65b0\u589e\u7684\u4fbf\u5229\u7b97\u6cd5<\/a><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"C11%E7%9A%84%E5%85%B6%E4%BB%96%E7%89%B9%E6%80%A7\"><\/span>C++11\u7684\u5176\u4ed6\u7279\u6027<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E5%A7%94%E6%89%98%E6%9E%84%E9%80%A0%E5%87%BD%E6%95%B0%E5%92%8C%E7%BB%A7%E6%89%BF%E6%9E%84%E9%80%A0%E5%87%BD%E6%95%B0\"><\/span>\u59d4\u6258\u6784\u9020\u51fd\u6570\u548c\u7ee7\u627f\u6784\u9020\u51fd\u6570<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u59d4\u6258\u6784\u9020\u51fd\u6570<\/strong>\uff1a\u5728\u4e00\u4e2a\u6784\u9020\u51fd\u6570\u4e2d\u53ef\u4ee5\u8c03\u7528\u53e6\u5916\u4e00\u4e2a\u6784\u9020\u51fd\u6570\uff0c\u4f46\u662f\u5982\u679c\u4f7f\u7528\u4e86\u59d4\u6258\u6784\u9020\u51fd\u6570\u5c31\u4e0d\u80fd\u540c\u65f6\u4f7f\u7528\u7c7b\u6210\u5458\u521d\u59cb\u5316\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class class_c{\n  class_c(int my_max) {...}\n  class_c(int my_max, int my_min) : class_c(my_max) {...}\n};<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u7ee7\u627f\u6784\u9020\u51fd\u6570<\/strong>\uff1a\u6d3e\u751f\u7c7b\u4f1a\u9690\u85cf\u57fa\u7c7b\u540c\u540d\u51fd\u6570\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>struct Base {\n  int x;\n  double y;\n  string s;\n\n  Base(int i) :x(i), y(0){}\n  Base(int i, double j) :x(i), y(j){}\n  Base(int i, double j, const string&amp; str) :x(i), y(j), s(str){}\n};\n\nstruct Derived : Base {\n};\n\nint main() {\n  Derived d(1, 2.5, \"ok\"); \/\/\u9519\u8bef\uff0c\u6ca1\u6709\u76f8\u5e94\u7684\u6784\u9020\u51fd\u6570\n  return 0;\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e3a\u4e86\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0c\u8981\u4e48\u662f\u5728\u6d3e\u751f\u7c7b\u4e2d\u91cd\u65b0\u5b9a\u4e49\u4e00\u6b21\u6240\u6709\u7684\u6784\u9020\u51fd\u6570\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>struct Derived : Base {\n  Derived(int i) :Base(i) {}\n  Derived(int i, double j) :Base(i, j) {}\n  Derived(int i, double j, string&amp; str) :Base(i, j, str) {]\n};<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8981\u4e48\u901a\u8fc7using\u6765\u58f0\u660e\u4f7f\u7528\u57fa\u7c7b\u7684\u51fd\u6570(\u4e0d\u4ec5\u4ec5\u662f\u6784\u9020\u51fd\u6570)\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>struct Derived : Base {\n  using Base::Base;\n};\n\nint main()\n{\n  int i = 1;\n  double j = 1.23;\n  Derived d(i);\n  Derived d1(i, j);\n  Derived d2(i, j, \"\");\n  return 0;\n}<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E5%8E%9F%E5%A7%8B%E5%AD%97%E9%9D%A2%E9%87%8F\"><\/span>\u539f\u59cb\u5b57\u9762\u91cf<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"final%E5%92%8Coverride%E6%A0%87%E8%AF%86%E7%AC%A6\"><\/span>final\u548coverride\u6807\u8bc6\u7b26<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">final\u9650\u5236\u67d0\u4e2a\u7c7b\u4e0d\u80fd\u88ab\u7ee7\u627f\u6216\u8005\u67d0\u4e2a\u865a\u51fd\u6570\u4e0d\u80fd\u88ab\u91cd\u5199\uff0c\u5e76\u4e14\u8fd9\u4e2a\u5173\u952e\u5b57\u8981\u653e\u5230\u7c7b\u6216\u8005\u865a\u51fd\u6570\u7684\u540e\u9762\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>     struct A\n     {\n       virtual void foo() final;\n     };\n     struct B final : A\n     {\n       void foo();\n     };<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">override\u7528\u6765\u8868\u660e\u8fd9\u4e2a\u51fd\u6570\u662f\u8981\u7528\u6765\u91cd\u5199\u57fa\u7c7b\u7684\u865a\u51fd\u6570\u7684\uff0c\u9632\u6b62\u4e0d\u5c0f\u5fc3\u628a\u91cd\u5199\u865a\u51fd\u6570\u641e\u6210\u91cd\u8f7d\u3002\u8fd9\u4e2a\u5173\u952e\u5b57\u4e5f\u5fc5\u987b\u8981\u653e\u5728\u51fd\u6570\u7684\u540e\u9762\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>     struct A\n     {\n       virtual void func(){}\n     };\n     struct D: A{\n       void func() override {}\n     };<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E5%86%85%E5%AD%98%E5%AF%B9%E9%BD%90\"><\/span>\u5185\u5b58\u5bf9\u9f50<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E4%B8%BA%E4%BB%80%E4%B9%88%E6%9C%89%E5%86%85%E5%AD%98%E5%AF%B9%E9%BD%90\"><\/span>\u4e3a\u4ec0\u4e48\u6709\u5185\u5b58\u5bf9\u9f50<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<ul class=\"wp-block-list\"><li>\u4e3a\u4e86\u6027\u80fd\u3002\u7531\u4e8e\u5185\u5b58\u786c\u4ef6\u4e0a\u7684\u7ec4\u7ec7\u65b9\u5f0f(\u5177\u4f53\u770b<a href=\"https:\/\/www.geeksforgeeks.org\/structure-member-alignment-padding-and-data-packing\/\">\u8fd9\u7bc7\u4ecb\u7ecd\u5185\u5b58\u5bf9\u9f50\u7684\u6587\u7ae0<\/a>)\uff0c\u4ece\u5185\u5b58\u4e2d\u8bfb\u53d6\u6570\u636e\u65f6\u5f80\u5f80\u662f\u4e00\u6b21\u6027\u8bfb\u53d64\u5b57\u8282\u30018\u5b57\u8282\uff0c\u4e3a\u4e86\u80fd\u591f\u5c3d\u53ef\u80fd\u5730\u63d0\u5347\u8bfb\u5199\u5185\u5b58\u7684\u6548\u7387\uff0c\u4e8e\u662f\u6709\u4e86\u5185\u5b58\u5bf9\u9f50\u7684\u6982\u5ff5\u3002\u50cf\u4e00\u4e9bSSE\u4e4b\u7c7b\u7684\u6307\u4ee4\u5bf9\u6570\u636e\u4e5f\u6709\u7740\u5bf9\u9f50\u4e0a\u7684\u8981\u6c42\u3002<\/li><li>CPU\u5bfb\u5740\u652f\u6301\u3002\u6bd4\u5982\u5728\u67d0\u4e9b\u5e73\u53f0\u4e0a\u5982\u679c\u4f60\u628aint\u5b58\u653e\u5728\u4e0d\u662f4\u7684\u500d\u6570\u5f00\u5934\u7684\u5730\u5740\uff0c\u90a3\u4e48\u4f60\u53bb\u5b58\u53d6\u8fd9\u4e2aint\u7684\u65f6\u5019\u662f\u4f1a\u62a5Bus Error(SIGBUS)\u7684\u3002\u5199\u8fc7\u79fb\u52a8\u7aefsdk\u7684\u4eba\u5e94\u8be5\u5bf9\u6b64\u6df1\u6709\u4f53\u4f1a\u3002\u5728x86\u5e73\u53f0\u4e0a\u5219\u6ca1\u6709\u8fd9\u79cd\u95ee\u9898\u3002<\/li><\/ul>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E5%86%85%E5%AD%98%E5%AF%B9%E9%BD%90%E5%85%B7%E4%BD%93%E8%A6%81%E6%B1%82\"><\/span>\u5185\u5b58\u5bf9\u9f50\u5177\u4f53\u8981\u6c42<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u5bf9\u4e8e\u57fa\u672c\u6570\u636e\u7c7b\u578b\uff0c\u8fd9\u4e9b\u6570\u636e\u7684\u5185\u5b58\u5730\u5740\u5fc5\u987b\u662f\u5176\u5bf9\u9f50\u957f\u5ea6\u7684\u500d\u6570\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><tbody><tr><td>Data Type<\/td><td>32-bit (bytes)<\/td><td>64-bit (bytes)<\/td><\/tr><tr><td>char<\/td><td>1<\/td><td>1<\/td><\/tr><tr><td>short<\/td><td>2<\/td><td>2<\/td><\/tr><tr><td>int<\/td><td>4<\/td><td>4<\/td><\/tr><tr><td>long<\/td><td>8<\/td><td>8<\/td><\/tr><tr><td>float<\/td><td>4<\/td><td>4<\/td><\/tr><tr><td>double<\/td><td>8<\/td><td>8<\/td><\/tr><tr><td>long long<\/td><td>8<\/td><td>8<\/td><\/tr><tr><td>long double<\/td><td>4<\/td><td>16<\/td><\/tr><tr><td>Any pointer<\/td><td>4<\/td><td>8<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u5bf9\u4e8e\u7ed3\u6784\u4f53\uff0c\u5176\u5bf9\u9f50\u957f\u5ea6\u662f\u5176\u6210\u5458\u91cc\u5bf9\u9f50\u957f\u5ea6\u6700\u5927\u7684\u90a3\u4e00\u4e2a\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e3a\u4e86\u7167\u987e\u5185\u5b58\u5bf9\u9f50\uff0c\u7ed3\u6784\u4f53\u7684\u5185\u90e8\u548c\u672b\u5c3e\u4f1a\u4ea7\u751fpadding\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6bd4\u5982<a href=\"https:\/\/software.intel.com\/content\/www\/us\/en\/develop\/articles\/coding-for-performance-data-alignment-and-structures.html\">intel\u8fd9\u7bc7\u6587\u6863\u91cc\u7684\u4f8b\u5b50<\/a>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>  struct s1\n  {\n    char a;\n    short a1;\n    char b1;\n    float b;\n    int c;\n    char e;\n    double f;\n  };\n  struct s2\n  {\n    double f;\n    float b;\n    short a1;\n    char a,b1,e;\n  };<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ed3\u6784\u4f53s1\u8981\u5360\u752832\u4e2a\u5b57\u8282\uff0c\u5185\u90e8\u670911\u4e2a\u5b57\u8282\u7684padding\uff0c\u800c\u6210\u5458\u76f8\u540c\u7684\u7ed3\u6784\u4f53s2\u53ea\u5360\u752824\u4e2a\u5b57\u8282\uff0c\u53ea\u6709\u672b\u5c3e\u76843\u4e2a\u5b57\u8282\u7684padding\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E8%B8%A9%E8%BF%87%E5%86%85%E5%AD%98%E5%AF%B9%E9%BD%90%E7%9A%84%E5%93%AA%E4%BA%9B%E5%9D%91\"><\/span>\u8e29\u8fc7\u5185\u5b58\u5bf9\u9f50\u7684\u54ea\u4e9b\u5751<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<ul class=\"wp-block-list\"><li>\u5199\u79fb\u52a8\u7aefsdk\u7684\u4eba\u7ecf\u5e38\u4f1a\u9047\u5230\u6ca1\u6ce8\u610f\u5185\u5b58\u5bf9\u9f50\uff0c\u5bfc\u81f4\u62a5SIGBUS\u7684\u95ee\u9898\uff1b<br>\u4e3a\u4e86\u5199\u51fa\u66f4portable\u548c\u5065\u58ee\u7684\u4ee3\u7801\uff0c\u9700\u8981\u7559\u610f\u6570\u636e\u7c7b\u578b\u7684\u5bf9\u9f50\u8981\u6c42\uff1b<\/li><li>\u56e0\u4e3a\u5ffd\u7565\u4e86\u5185\u5b58\u5bf9\u9f50\u7684\u5f71\u54cd\uff0c\u5728\u624b\u52a8\u8ba1\u7b97\u7ed3\u6784\u4f53\u5927\u5c0f\u548c\u6210\u5458\u53d8\u91cf\u7684\u504f\u79fb\u91cf\u65f6\u7ecf\u5e38\u51fa\u9519\uff1b<br>\u8fd9\u79cd\u9519\u8bef\u633a\u5751\u7684\uff0c\u53ef\u80fd\u4f60\u672c\u610f\u662f\u6253\u7b97\u5b58\u53d6\u67d0\u4e2a\u6210\u5458\u53d8\u91cf\u7684\uff0c\u5b9e\u9645\u4e0a\u5374\u64cd\u4f5c\u7684\u662f\u4f5c\u4e3apadding\u7684\u65e0\u7528\u6570\u636e\uff0c\u5728\u5e8f\u5217\u5316\u53cd\u5e8f\u5217\u5316\u4f20\u9012\u6570\u636e\u65f6\u5c31\u4f1a\u9047\u5230\u8fd9\u79cd\u5751\uff1b<br>\u89e3\u51b3\u529e\u6cd5\u5c31\u662f\u8981\u4e48\u7262\u8bb0\u5185\u5b58\u5bf9\u9f50\u7684\u89c4\u5219\uff0c\u8981\u4e48\u8bf7\u719f\u7ec3\u4f7f\u7528sizeof\u548coffsetof\u4e24\u4e2a\u5b8f\uff1b<\/li><\/ul>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E7%90%86%E8%A7%A3%E4%BA%86%E5%86%85%E5%AD%98%E5%AF%B9%E9%BD%90%E5%90%8E%E5%8F%AF%E4%BB%A5%E6%80%8E%E6%A0%B7%E6%8A%8A%E7%A8%8B%E5%BA%8F%E5%86%99%E7%9A%84%E6%9B%B4%E5%A5%BD\"><\/span>\u7406\u89e3\u4e86\u5185\u5b58\u5bf9\u9f50\u540e\u53ef\u4ee5\u600e\u6837\u628a\u7a0b\u5e8f\u5199\u7684\u66f4\u597d<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<ul class=\"wp-block-list\"><li>\u5f53\u7136\u662f\u907f\u514d\u4e0a\u9762\u5217\u51fa\u7684\u90a3\u4e9b\u5751\uff1b<\/li><li>\u53c2\u7167intel\u6587\u6863\u7684\u90a3\u4e2a\u4f8b\u5b50\uff0c\u5408\u7406\u5b89\u6392\u6210\u5458\u53d8\u91cf\u7684\u987a\u5e8f\u8282\u7ea6\u7a7a\u95f4\uff1b<\/li><li>\u5bf9\u4e8e\u67d0\u4e9b\u7ed3\u6784\u4f53\uff0c\u624b\u52a8\u8bbe\u7f6e\u5176\u5185\u5b58\u5bf9\u9f50\u957f\u5ea6\uff0c\u63d0\u5347\u5176\u5728cache\u4e0a\u7684\u6027\u80fd\uff1b<\/li><\/ul>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"malloc%E4%B8%8E%E5%86%85%E5%AD%98%E5%AF%B9%E9%BD%90\"><\/span>malloc\u4e0e\u5185\u5b58\u5bf9\u9f50<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">malloc\u51fd\u6570\u8fd4\u56de\u503c\u662f\u4e00\u4e2a\u6309\u7167max_align_t\u5bf9\u9f50\u7684\u5730\u5740\uff0c\u8fd9\u4e2amax_align_t\u4e00\u822c\u662f8\u548c16\uff0c\u6309max_align_t\u5bf9\u9f50\u4fdd\u8bc1\u4e86\u6240\u6709\u57fa\u672c\u6570\u636e\u7c7b\u578b\u90fd\u53ef\u4ee5\u653e\u5728malloc\u8fd4\u56de\u5730\u5740\u5f00\u5934\u7684\u5185\u5b58\u91cc\uff1b<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"c11%E4%B8%AD%E6%8F%90%E4%BE%9B%E7%9A%84%E5%86%85%E5%AD%98%E5%AF%B9%E9%BD%90%E7%9B%B8%E5%85%B3%E5%B7%A5%E5%85%B7\"><\/span>c++11\u4e2d\u63d0\u4f9b\u7684\u5185\u5b58\u5bf9\u9f50\u76f8\u5173\u5de5\u5177<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>alignas<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>alignas(32) long long a = 0;\n\nstruct alignas(32) MyStruct {\n};\n\nalignas(int) char c;<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">alignas\u652f\u6301\u628aalignment\u6539\u5927\uff0c\u4e0d\u80fd\u652f\u6301\u6539\u5c0f\u3002\u8981\u6539\u5c0f\u9700\u8981\u4f7f\u7528#pragma pack\u6216\u8005C++11\u4e2d\u7b49\u4ef7\u7684_Pragma\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>_Pragma(\"pack(1)\")\nstruct MyStruct {\n  char a;\n  int b;\n  short c;\n  long long d;\n  char e;\n};\n_Pragma(\"pack()\")<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>alignof<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7528\u4e8e\u83b7\u53d6alignment\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u91cc\u8fd8\u8bb2\u4e86\u4e00\u4e2a<a href=\"https:\/\/en.cppreference.com\/w\/cpp\/language\/sizeof...\">sizeof&#8230;\u7684\u7528\u6cd5<\/a>\uff0c\u7528\u4e8e\u83b7\u53d6\u53d8\u53c2\u7684\u4e2a\u6570\u3002alignof\u5b58\u5728\u7c7b\u4f3c\u7684\u7528\u6cd5\uff0c\u7528\u4e8e\u83b7\u53d6\u53d8\u53c2\u7684alignment\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>std::alignment_of<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>template&lt; class T &gt;\nstruct alignment_of : std::integral_constant&lt;\n                          std::size_t,\n                          alignof(T)\n                       &gt; {};<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u548calignof\u6548\u679c\u4e00\u6837\uff0c\u901a\u8fc7::value\u83b7\u53d6alignment\u5927\u5c0f\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>std::aligned_storage<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>template&lt; std::size_t Len, std::size_t Align = \/*default-alignment*\/ &gt;\nstruct aligned_storage;\n\n\ntemplate&lt;std::size_t Len, std::size_t Align \/* default alignment not implemented *\/&gt;\nstruct aligned_storage {\n    struct type {\n        alignas(Align) unsigned char data&#91;Len];\n    };\n};<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u7528\u4e8e\u58f0\u660e\u4e00\u5757\u957f\u5ea6\u4e3aLen\uff0c\u6309Align\u5bf9\u9f50\u7684\u5185\u5b58\u3002\u914d\u5408placement new\u4f7f\u7528\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>std::align<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>void* align( std::size_t alignment,\n             std::size_t size,\n             void*&amp; ptr,\n             std::size_t&amp; space );<\/code><\/pre>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p>Given a pointer\u00a0<em>ptr<\/em>\u00a0to a buffer of size\u00a0<em>space<\/em>, returns a pointer aligned by the specified\u00a0<em>alignment<\/em>\u00a0for\u00a0<em>size<\/em>\u00a0number of bytes and decreases\u00a0<em>space<\/em>\u00a0argument by the number of bytes used for alignment. The first aligned address is returned.<\/p><p>The function modifies the pointer only if it would be possible to fit the wanted number of bytes aligned by the given alignment into the buffer. If the buffer is too small, the function does nothing and returns\u00a0nullptr.<\/p><\/blockquote>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"C11%E6%96%B0%E5%A2%9E%E7%9A%84%E4%BE%BF%E5%88%A9%E7%AE%97%E6%B3%95\"><\/span>C++11\u65b0\u589e\u7684\u4fbf\u5229\u7b97\u6cd5<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul class=\"wp-block-list\"><li>all_of\u3001any_of\u548cnone_of<\/li><li>find_if_not<\/li><li>copy_if<\/li><li>iota<\/li><li>minmax_elemen<\/li><li>is_sorted\u548cis_sorted_until<\/li><\/ul>\n","protected":false},"excerpt":{"rendered":"<p>C++11\u7684\u5176\u4ed6\u7279\u6027 \u59d4\u6258\u6784\u9020\u51fd\u6570\u548c\u7ee7\u627f\u6784\u9020\u51fd\u6570 \u59d4\u6258\u6784\u9020\u51fd\u6570\uff1a\u5728\u4e00\u4e2a\u6784\u9020\u51fd\u6570\u4e2d\u53ef\u4ee5\u8c03\u7528\u53e6\u5916\u4e00\u4e2a\u6784\u9020\u51fd\u6570\uff0c\u4f46\u662f\u5982\u679c\u4f7f\u7528\u4e86\u59d4\u6258\u6784\u9020\u51fd\u6570\u5c31\u4e0d\u80fd\u540c\u65f6\u4f7f\u7528\u7c7b\u6210\u5458\u521d\u59cb\u5316\u3002 \u7ee7\u627f\u6784\u9020\u51fd\u6570\uff1a\u6d3e\u751f\u7c7b\u4f1a\u9690\u85cf\u57fa\u7c7b\u540c\u540d\u51fd\u6570&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[8,7,9],"class_list":["post-39","post","type-post","status-publish","format-standard","hentry","category-10","tag-c","tag-c11","tag-9"],"_links":{"self":[{"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=\/wp\/v2\/posts\/39","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=39"}],"version-history":[{"count":6,"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=\/wp\/v2\/posts\/39\/revisions"}],"predecessor-version":[{"id":112,"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=\/wp\/v2\/posts\/39\/revisions\/112"}],"wp:attachment":[{"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=39"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=39"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=39"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}