{"id":1933,"date":"2025-03-24T08:49:35","date_gmt":"2025-03-23T23:49:35","guid":{"rendered":"https:\/\/dexall.co.jp\/articles\/?p=1933"},"modified":"2025-03-24T08:49:35","modified_gmt":"2025-03-23T23:49:35","slug":"c-constexpr%e3%83%9e%e3%82%b9%e3%82%bf%e3%83%bc%e3%82%ac%e3%82%a4%e3%83%89%ef%bc%9a%e3%83%91%e3%83%95%e3%82%a9%e3%83%bc%e3%83%9e%e3%83%b3%e3%82%b9%e3%82%922%e5%80%8d%e3%81%ab%e5%90%91%e4%b8%8a","status":"publish","type":"post","link":"https:\/\/dexall.co.jp\/articles\/?p=1933","title":{"rendered":"C++ constexpr\u30de\u30b9\u30bf\u30fc\u30ac\u30a4\u30c9\uff1a\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u30922\u500d\u306b\u5411\u4e0a\u3055\u305b\u308b\u5b9f\u8df5\u30c6\u30af\u30cb\u30c3\u30af"},"content":{"rendered":"\n<div class=\"toc\"><br \/>\n<b>Warning<\/b>:  Undefined array key \"is_admin\" in <b>\/home\/xs392991\/dexall.co.jp\/public_html\/articles\/wp-content\/themes\/sango-theme\/library\/gutenberg\/dist\/classes\/Toc.php<\/b> on line <b>116<\/b><br \/>\n<br \/>\n<b>Warning<\/b>:  Undefined array key \"is_category_top\" in <b>\/home\/xs392991\/dexall.co.jp\/public_html\/articles\/wp-content\/themes\/sango-theme\/library\/gutenberg\/dist\/classes\/Toc.php<\/b> on line <b>121<\/b><br \/>\n<br \/>\n<b>Warning<\/b>:  Undefined array key \"is_top\" in <b>\/home\/xs392991\/dexall.co.jp\/public_html\/articles\/wp-content\/themes\/sango-theme\/library\/gutenberg\/dist\/classes\/Toc.php<\/b> on line <b>128<\/b><br \/>\n    <div id=\"toc_container\" class=\"sgb-toc--bullets js-smooth-scroll\" data-dialog-title=\"\u76ee\u6b21\">\n      <p class=\"toc_title\">\u76ee\u6b21 <\/p>\n      <ul class=\"toc_list\">  <li class=\"first\">    <a href=\"#i-0\">constexpr\u5165\u9580\uff1a\u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u8a08\u7b97\u306e\u5a01\u529b\u3092\u89e3\u8aac<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-1\">constexpr\u304c\u89e3\u6c7a\u3059\u308b3\u3064\u306e\u958b\u767a\u8ab2\u984c<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-2\">\u5f93\u6765\u306econst\u3068\u306e\u6c7a\u5b9a\u7684\u306a\u9055\u3044<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-3\">constexpr\u306e\u57fa\u672c\u6587\u6cd5\u3068\u6d3b\u7528\u30b7\u30fc\u30f3<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-4\">constexpr\u95a2\u6570\u306e\u5b9a\u7fa9\u65b9\u6cd5\u3068\u4f9d\u5b58\u4e8b\u9805<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-5\">constexpr\u5909\u6570\u3092\u4f7f\u3063\u305f\u6700\u9069\u5316\u30c6\u30af\u30cb\u30c3\u30af<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-6\">\u5b9f\u8df5\u7684\u306aconstexpr\u306e\u6d3b\u7528\u30d1\u30bf\u30fc\u30f3<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-7\">\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30e1\u30bf\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u3068\u306e\u7d44\u307f\u5408\u308f\u305b<\/a>      <\/li>      <li>        <a href=\"#i-8\">\u6570\u5024\u8a08\u7b97\u306e\u6700\u9069\u5316\u4e8b\u4f8b<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-9\">\u6587\u5b57\u5217\u51e6\u7406\u3067\u306e\u6d3b\u7528\u65b9\u6cd5<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-10\">constexpr\u306b\u3088\u308b\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u6539\u5584<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-11\">\u5b9f\u884c\u6642\u9593\u309250%\u524a\u6e1b\u3057\u305f\u5b9f\u88c5\u4f8b<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-12\">\u30e1\u30e2\u30ea\u4f7f\u7528\u91cf\u306e\u6700\u9069\u5316\u30c6\u30af\u30cb\u30c3\u30af<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-13\">C++20\u3067\u5f37\u5316\u3055\u308c\u305fconstexpr\u6a5f\u80fd<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-14\">constexpr virtual\u95a2\u6570\u306e\u5b9f\u88c5\u65b9\u6cd5<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-15\">constinit\u6a5f\u80fd\u3068\u306e\u4f7f\u3044\u65b9<\/a>      <\/li>    <\/ul>  <\/li>  <li class=\"last\">    <a href=\"#i-16\">constexpr\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9\u3068\u30a2\u30f3\u30c1\u30d1\u30bf\u30fc\u30f3<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-17\">\u30ec\u30d3\u30e5\u30fc\u3067\u6307\u6458\u3055\u308c\u3084\u3059\u3044\u5b9f\u88c5\u30df\u30b9<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-18\">\u4fdd\u5b88\u6027\u3092\u9ad8\u3081\u308b\u30b3\u30fc\u30c9\u8a2d\u8a08<\/a>      <\/li>    <\/ul>  <\/li><\/ul>\n      <a href=\"#\" class=\"sgb-toc-button js-toc-button\" rel=\"nofollow\" data-open-dialog=\"true\"><i class=\"fa fa-list\"><\/i><span class=\"sgb-toc-button__text\">\u76ee\u6b21\u3078<\/span><\/a>\n    <\/div><\/div><h2 class=\"wp-block-heading\" id=\"i-0\">constexpr\u5165\u9580\uff1a\u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u8a08\u7b97\u306e\u5a01\u529b\u3092\u89e3\u8aac<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-1\">constexpr\u304c\u89e3\u6c7a\u3059\u308b3\u3064\u306e\u958b\u767a\u8ab2\u984c<\/h3>\n\n\n\n<p>C++\u958b\u767a\u306b\u304a\u3044\u3066\u3001\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306f\u5e38\u306b\u91cd\u8981\u306a\u8ab2\u984c\u3067\u3059\u3002<code>constexpr<\/code>\u306f\u3001\u4ee5\u4e0b\u306e3\u3064\u306e\u958b\u767a\u8ab2\u984c\u3092\u52b9\u679c\u7684\u306b\u89e3\u6c7a\u3057\u307e\u3059\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u5b9f\u884c\u6642\u306e\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u30aa\u30fc\u30d0\u30fc\u30d8\u30c3\u30c9<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5f93\u6765\u306e\u8a08\u7b97\u51e6\u7406\u306f\u5b9f\u884c\u6642\u306b\u884c\u308f\u308c\u308b\u305f\u3081\u3001\u7279\u306b\u7e70\u308a\u8fd4\u3057\u5b9f\u884c\u3055\u308c\u308b\u51e6\u7406\u3067\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u304c\u4f4e\u4e0b<\/li>\n\n\n\n<li><code>constexpr<\/code>\u3092\u4f7f\u7528\u3059\u308b\u3053\u3068\u3067\u3001\u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u8a08\u7b97\u3092\u5b8c\u4e86\u3057\u3001\u5b9f\u884c\u6642\u306e\u30aa\u30fc\u30d0\u30fc\u30d8\u30c3\u30c9\u3092\u524a\u6e1b<\/li>\n<\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   \/\/ \u5b9f\u884c\u6642\u306b\u8a08\u7b97\u304c\u5fc5\u8981\u306a\u4f8b\n   const int value = calculate_value(10);  \/\/ \u5b9f\u884c\u6642\u306b\u8a08\u7b97\n\n   \/\/ \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u8a08\u7b97\u304c\u5b8c\u4e86\u3059\u308b\u4f8b\n   constexpr int value = calculate_value(10);  \/\/ \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u8a08\u7b97\u5b8c\u4e86<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30e1\u30bf\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u306e\u8907\u96d1\u6027<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5f93\u6765\u306e\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30e1\u30bf\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u306f\u8a18\u8ff0\u304c\u8907\u96d1\u3067\u53ef\u8aad\u6027\u304c\u4f4e\u3044<\/li>\n\n\n\n<li><code>constexpr<\/code>\u3092\u4f7f\u7528\u3059\u308b\u3053\u3068\u3067\u3001\u901a\u5e38\u306e\u95a2\u6570\u5f62\u5f0f\u3067\u76f4\u611f\u7684\u306b\u30e1\u30bf\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u3092\u5b9f\u73fe<\/li>\n<\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   \/\/ \u5f93\u6765\u306e\u8907\u96d1\u306a\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30e1\u30bf\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\n   template&lt;int N&gt;\n   struct Factorial {\n       static const int value = N * Factorial&lt;N-1&gt;::value;\n   };\n\n   \/\/ constexpr\u3092\u4f7f\u7528\u3057\u305f\u7c21\u6f54\u306a\u5b9f\u88c5\n   constexpr int factorial(int n) {\n       return n &lt;= 1 ? 1 : n * factorial(n - 1);\n   }<\/pre>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li><strong>\u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u5b9a\u6570\u306e\u67d4\u8edf\u6027\u4e0d\u8db3<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5f93\u6765\u306e<code>const<\/code>\u3067\u306f\u5b9f\u73fe\u3067\u304d\u306a\u3044\u8907\u96d1\u306a\u5b9a\u6570\u8a08\u7b97\u304c\u5fc5\u8981\u306a\u30b1\u30fc\u30b9<\/li>\n\n\n\n<li><code>constexpr<\/code>\u306b\u3088\u308a\u3001\u95a2\u6570\u3084\u30af\u30e9\u30b9\u30e1\u30f3\u30d0\u95a2\u6570\u3067\u3082\u5b9a\u6570\u5f0f\u3092\u5b9a\u7fa9\u53ef\u80fd\u306b<\/li>\n<\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   \/\/ \u8907\u96d1\u306a\u8a08\u7b97\u3092\u542b\u3080\u5b9a\u6570\u5b9a\u7fa9\n   constexpr int calculate_buffer_size(int input_size) {\n       return input_size * 2 + 32;  \/\/ \u30d0\u30c3\u30d5\u30a1\u30b5\u30a4\u30ba\u306e\u52d5\u7684\u306a\u8a08\u7b97\n   }\n\n   \/\/ \u914d\u5217\u30b5\u30a4\u30ba\u306a\u3069\u3067\u306e\u6d3b\u7528\n   constexpr int size = calculate_buffer_size(64);\n   std::array&lt;int, size&gt; buffer;  \/\/ \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u914d\u5217\u30b5\u30a4\u30ba\u304c\u6c7a\u5b9a<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-2\">\u5f93\u6765\u306econst\u3068\u306e\u6c7a\u5b9a\u7684\u306a\u9055\u3044<\/h3>\n\n\n\n<p><code>constexpr<\/code>\u3068<code>const<\/code>\u306e\u4e3b\u306a\u9055\u3044\u306f\u3001\u4ee5\u4e0b\u306e3\u70b9\u306b\u96c6\u7d04\u3055\u308c\u307e\u3059\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u8a08\u7b97\u306e\u30bf\u30a4\u30df\u30f3\u30b0<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>const<\/code>: \u5b9f\u884c\u6642\u306b\u5024\u304c\u78ba\u5b9a<\/li>\n\n\n\n<li><code>constexpr<\/code>: \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u5024\u304c\u78ba\u5b9a<\/li>\n<\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   const int run_time = get_value();  \/\/ \u5b9f\u884c\u6642\u306b\u5024\u304c\u6c7a\u5b9a\n   constexpr int compile_time = 10 * 20;  \/\/ \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u5024\u304c\u6c7a\u5b9a<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u4f7f\u7528\u53ef\u80fd\u306a\u6587\u8108<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>const<\/code>: \u5909\u6570\u306e\u4e0d\u5909\u6027\u306e\u307f\u3092\u4fdd\u8a3c<\/li>\n\n\n\n<li><code>constexpr<\/code>: \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u5b9a\u6570\u304c\u5fc5\u8981\u306a\u5834\u6240\uff08\u914d\u5217\u30b5\u30a4\u30ba\u3001\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30d1\u30e9\u30e1\u30fc\u30bf\u306a\u3069\uff09\u3067\u4f7f\u7528\u53ef\u80fd<\/li>\n<\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   const int size1 = 100;\n   int array1[size1];  \/\/ \u30a8\u30e9\u30fc\uff1aconst\u5909\u6570\u306f\u914d\u5217\u30b5\u30a4\u30ba\u306b\u4f7f\u7528\u4e0d\u53ef\n\n   constexpr int size2 = 100;\n   int array2[size2];  \/\/ OK\uff1aconstexpr\u5909\u6570\u306f\u914d\u5217\u30b5\u30a4\u30ba\u306b\u4f7f\u7528\u53ef\u80fd<\/pre>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li><strong>\u95a2\u6570\u5b9a\u7fa9\u3067\u306e\u9055\u3044<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>const<\/code>\u30e1\u30f3\u30d0\u95a2\u6570\uff1a\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u72b6\u614b\u3092\u5909\u66f4\u3057\u306a\u3044\u3053\u3068\u3092\u4fdd\u8a3c<\/li>\n\n\n\n<li><code>constexpr<\/code>\u95a2\u6570\uff1a\u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u5b9f\u884c\u304c\u53ef\u80fd\u3067\u3042\u308b\u3053\u3068\u3092\u4fdd\u8a3c<\/li>\n<\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">   class Example {\n       int value;\n   public:\n       const int getValue() const {  \/\/ \u5358\u306a\u308b\u8aad\u307f\u53d6\u308a\u5c02\u7528\u95a2\u6570\n           return value;\n       }\n\n       constexpr int calculateValue(int input) const {  \/\/ \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u5b9f\u884c\u53ef\u80fd\n           return input * value + 42;\n       }\n   };<\/pre>\n\n\n\n<p>\u3053\u306e\u9055\u3044\u3092\u7406\u89e3\u3059\u308b\u3053\u3068\u3067\u3001<code>constexpr<\/code>\u3092\u9069\u5207\u306a\u5834\u9762\u3067\u6d3b\u7528\u3057\u3001\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3068\u4fdd\u5b88\u6027\u306e\u4e21\u65b9\u3092\u5411\u4e0a\u3055\u305b\u308b\u3053\u3068\u304c\u53ef\u80fd\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-3\">constexpr\u306e\u57fa\u672c\u6587\u6cd5\u3068\u6d3b\u7528\u30b7\u30fc\u30f3<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-4\">constexpr\u95a2\u6570\u306e\u5b9a\u7fa9\u65b9\u6cd5\u3068\u4f9d\u5b58\u4e8b\u9805<\/h3>\n\n\n\n<p>constexpr\u95a2\u6570\u3092\u5b9a\u7fa9\u3059\u308b\u969b\u306b\u306f\u3001\u4ee5\u4e0b\u306e\u91cd\u8981\u306a\u8981\u4ef6\u3068\u5236\u7d04\u3092\u7406\u89e3\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u57fa\u672c\u7684\u306a\u95a2\u6570\u5b9a\u7fa9<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u5358\u7d14\u306a\u6570\u5024\u8a08\u7b97\u306e\u4f8b\nconstexpr int square(int x) {\n    return x * x;\n}\n\n\/\/ \u518d\u5e30\u7684\u306a\u8a08\u7b97\u3082\u53ef\u80fd\nconstexpr int fibonacci(int n) {\n    return n &lt;= 1 ? n : fibonacci(n-1) + fibonacci(n-2);\n}<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u5236\u7d04\u4e8b\u9805<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u3059\u3079\u3066\u306e\u5f15\u6570\u306f\u30ea\u30c6\u30e9\u30eb\u578b\u3067\u3042\u308b\u5fc5\u8981\u304c\u3042\u308b<\/li>\n\n\n\n<li>\u5358\u4e00\u306ereturn\u6587\u306e\u307f\uff08C++14\u4ee5\u964d\u306f\u7de9\u548c\uff09<\/li>\n\n\n\n<li>\u526f\u4f5c\u7528\u3092\u6301\u3064\u64cd\u4f5c\u306f\u7981\u6b62\uff08\u30d5\u30a1\u30a4\u30ebI\/O\u3001\u9759\u7684\u5909\u6570\u306e\u5909\u66f4\u306a\u3069\uff09<\/li>\n<\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">constexpr int invalid_function() {\n    static int count = 0;  \/\/ \u30a8\u30e9\u30fc\uff1a\u9759\u7684\u5909\u6570\u306f\u4f7f\u7528\u4e0d\u53ef\n    return count++;        \/\/ \u30a8\u30e9\u30fc\uff1a\u526f\u4f5c\u7528\u3092\u6301\u3064\u64cd\u4f5c\n}<\/pre>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li><strong>C++17\u4ee5\u964d\u306e\u62e1\u5f35\u6a5f\u80fd<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">constexpr int modern_function(int x) {\n    if (x &lt; 0) return 0;  \/\/ if\u6587\u304c\u4f7f\u7528\u53ef\u80fd\n\n    int result = 0;\n    for (int i = 0; i &lt; x; ++i) {  \/\/ \u30eb\u30fc\u30d7\u3082\u4f7f\u7528\u53ef\u80fd\n        result += i;\n    }\n    return result;\n}<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-5\">constexpr\u5909\u6570\u3092\u4f7f\u3063\u305f\u6700\u9069\u5316\u30c6\u30af\u30cb\u30c3\u30af<\/h3>\n\n\n\n<p>constexpr\u5909\u6570\u3092\u52b9\u679c\u7684\u306b\u6d3b\u7528\u3059\u308b\u3053\u3068\u3067\u3001\u69d8\u3005\u306a\u6700\u9069\u5316\u304c\u53ef\u80fd\u306b\u306a\u308a\u307e\u3059\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u914d\u5217\u30b5\u30a4\u30ba\u306e\u52d5\u7684\u8a08\u7b97<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">constexpr size_t calculate_size(size_t input_size) {\n    return input_size * 2 + 16;  \/\/ \u30d0\u30c3\u30d5\u30a1\u30b5\u30a4\u30ba\u306e\u8a08\u7b97\n}\n\n\/\/ \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u914d\u5217\u30b5\u30a4\u30ba\u304c\u6c7a\u5b9a\nconstexpr size_t buffer_size = calculate_size(32);\nstd::array&lt;int, buffer_size&gt; buffer;<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u30eb\u30c3\u30af\u30a2\u30c3\u30d7\u30c6\u30fc\u30d6\u30eb\u306e\u6700\u9069\u5316<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u8a08\u7b97\u3055\u308c\u308b\u5909\u63db\u30c6\u30fc\u30d6\u30eb\nconstexpr std::array&lt;int, 256&gt; create_lookup_table() {\n    std::array&lt;int, 256&gt; table{};\n    for (int i = 0; i &lt; 256; ++i) {\n        table[i] = i * i;  \/\/ \u4f8b\uff1a2\u4e57\u5024\u306e\u30c6\u30fc\u30d6\u30eb\n    }\n    return table;\n}\n\nconstexpr auto lookup_table = create_lookup_table();<\/pre>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li><strong>\u6570\u5b66\u5b9a\u6570\u306e\u6700\u9069\u5316<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u9ad8\u7cbe\u5ea6\u306a\u6570\u5b66\u5b9a\u6570\u306e\u8a08\u7b97\nconstexpr double calculate_pi() {\n    double result = 3.0;\n    for (int i = 0; i &lt; 1000; ++i) {\n        \/\/ \u30e9\u30a4\u30d7\u30cb\u30c3\u30c4\u306e\u516c\u5f0f\u306b\u3088\u308b\u5186\u5468\u7387\u306e\u8a08\u7b97\n        result += (i % 2 ? -1.0 : 1.0) * 4.0 \/ (2.0 * i + 3.0);\n    }\n    return result;\n}\n\nconstexpr double PI = calculate_pi();<\/pre>\n\n\n\n<ol start=\"4\" class=\"wp-block-list\">\n<li><strong>\u6761\u4ef6\u5206\u5c90\u306e\u6700\u9069\u5316<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">template&lt;typename T&gt;\nconstexpr bool is_power_of_two(T value) {\n    return value &gt; 0 &amp;&amp; (value &amp; (value - 1)) == 0;\n}\n\n\/\/ \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u6761\u4ef6\u5206\u5c90\u304c\u89e3\u6c7a\ntemplate&lt;typename T&gt;\nconstexpr T align_to_power_of_two(T value) {\n    if constexpr (is_power_of_two(value)) {\n        return value;  \/\/ \u3059\u3067\u306b2\u306e\u7d2f\u4e57\n    } else {\n        return T(1) &lt;&lt; (sizeof(T) * 8 - __builtin_clz(value));\n    }\n}<\/pre>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u6700\u9069\u5316\u30c6\u30af\u30cb\u30c3\u30af\u3092\u9069\u5207\u306b\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u3067\u3001\u5b9f\u884c\u6642\u306e\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3092\u5927\u5e45\u306b\u5411\u4e0a\u3055\u305b\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u7279\u306b\u3001\u983b\u7e41\u306b\u5b9f\u884c\u3055\u308c\u308b\u8a08\u7b97\u3084\u3001\u5927\u304d\u306a\u914d\u5217\u306e\u521d\u671f\u5316\u306a\u3069\u3067\u52b9\u679c\u3092\u767a\u63ee\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-6\">\u5b9f\u8df5\u7684\u306aconstexpr\u306e\u6d3b\u7528\u30d1\u30bf\u30fc\u30f3<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-7\">\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30e1\u30bf\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u3068\u306e\u7d44\u307f\u5408\u308f\u305b<\/h3>\n\n\n\n<p>constexpr\u3068\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30e1\u30bf\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u3092\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u3067\u3001\u5f37\u529b\u306a\u9759\u7684\u8a08\u7b97\u6a5f\u80fd\u3092\u5b9f\u73fe\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u578b\u7279\u6027\u306e\u8a08\u7b97<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u578b\u306e\u30d7\u30ed\u30d1\u30c6\u30a3\u3092\u8a08\u7b97\u3059\u308bconstexpr\u95a2\u6570\ntemplate&lt;typename T&gt;\nconstexpr size_t calculate_alignment() {\n    if constexpr (std::is_class_v&lt;T&gt;) {\n        return alignof(T);  \/\/ \u30af\u30e9\u30b9\u578b\u306e\u5834\u5408\n    } else if constexpr (std::is_array_v&lt;T&gt;) {\n        return alignof(std::remove_all_extents_t&lt;T&gt;);  \/\/ \u914d\u5217\u578b\u306e\u5834\u5408\n    } else {\n        return alignof(T);  \/\/ \u305d\u306e\u4ed6\u306e\u578b\n    }\n}\n\n\/\/ \u4f7f\u7528\u4f8b\nconstexpr size_t int_align = calculate_alignment&lt;int&gt;();\nconstexpr size_t class_align = calculate_alignment&lt;std::string&gt;();<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u578b\u5909\u63db<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">template&lt;typename From, typename To&gt;\nconstexpr bool is_safe_numeric_cast() {\n    constexpr auto from_min = std::numeric_limits&lt;From&gt;::min();\n    constexpr auto from_max = std::numeric_limits&lt;From&gt;::max();\n    constexpr auto to_min = std::numeric_limits&lt;To&gt;::min();\n    constexpr auto to_max = std::numeric_limits&lt;To&gt;::max();\n\n    return static_cast&lt;long double&gt;(from_min) &gt;= static_cast&lt;long double&gt;(to_min) &amp;&amp;\n           static_cast&lt;long double&gt;(from_max) &lt;= static_cast&lt;long double&gt;(to_max);\n}<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-8\">\u6570\u5024\u8a08\u7b97\u306e\u6700\u9069\u5316\u4e8b\u4f8b<\/h3>\n\n\n\n<p>\u6570\u5024\u8a08\u7b97\u51e6\u7406\u3067constexpr\u3092\u6d3b\u7528\u3059\u308b\u3053\u3068\u3067\u3001\u5b9f\u884c\u6642\u306e\u30aa\u30fc\u30d0\u30fc\u30d8\u30c3\u30c9\u3092\u5927\u5e45\u306b\u524a\u6e1b\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u6570\u5b66\u95a2\u6570\u306e\u5b9f\u88c5<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u8a08\u7b97\u3055\u308c\u308b\u6307\u6570\u95a2\u6570\nconstexpr double exp_impl(double x, int terms) {\n    double result = 1.0;\n    double term = 1.0;\n    for (int i = 1; i &lt; terms; ++i) {\n        term *= x \/ i;\n        result += term;\n    }\n    return result;\n}\n\n\/\/ \u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u95a2\u6570\nconstexpr double exp(double x) {\n    return exp_impl(x, 20);  \/\/ \u9805\u6570\u306f\u7cbe\u5ea6\u3068\u306e\u30c8\u30ec\u30fc\u30c9\u30aa\u30d5\n}\n\n\/\/ \u4f7f\u7528\u4f8b\nconstexpr double e = exp(1.0);  \/\/ \u81ea\u7136\u5bfe\u6570\u306e\u5e95<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u884c\u5217\u6f14\u7b97\u306e\u6700\u9069\u5316<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">template&lt;size_t Rows, size_t Cols&gt;\nstruct Matrix {\n    std::array&lt;std::array&lt;double, Cols&gt;, Rows&gt; data;\n\n    \/\/ \u884c\u5217\u4e57\u7b97\n    template&lt;size_t OtherCols&gt;\n    constexpr Matrix&lt;Rows, OtherCols&gt; multiply(\n        const Matrix&lt;Cols, OtherCols&gt;&amp; other) const {\n        Matrix&lt;Rows, OtherCols&gt; result{};\n        for (size_t i = 0; i &lt; Rows; ++i) {\n            for (size_t j = 0; j &lt; OtherCols; ++j) {\n                double sum = 0;\n                for (size_t k = 0; k &lt; Cols; ++k) {\n                    sum += data[i][k] * other.data[k][j];\n                }\n                result.data[i][j] = sum;\n            }\n        }\n        return result;\n    }\n};<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-9\">\u6587\u5b57\u5217\u51e6\u7406\u3067\u306e\u6d3b\u7528\u65b9\u6cd5<\/h3>\n\n\n\n<p>\u6587\u5b57\u5217\u51e6\u7406\u306b\u304a\u3044\u3066\u3082\u3001constexpr\u3092\u6d3b\u7528\u3059\u308b\u3053\u3068\u3067\u52b9\u7387\u7684\u306a\u5b9f\u88c5\u304c\u53ef\u80fd\u3067\u3059\u3002<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u6587\u5b57\u5217\u30cf\u30c3\u30b7\u30e5<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">constexpr uint64_t hash_fnv1a(const char* str) {\n    constexpr uint64_t FNV_PRIME = 1099511628211ULL;\n    constexpr uint64_t FNV_OFFSET = 14695981039346656037ULL;\n\n    uint64_t hash = FNV_OFFSET;\n    for (const char* p = str; *p; ++p) {\n        hash ^= static_cast&lt;uint64_t&gt;(*p);\n        hash *= FNV_PRIME;\n    }\n    return hash;\n}\n\n\/\/ switch\u6587\u3067\u306e\u6d3b\u7528\u4f8b\nvoid process_command(const std::string&amp; cmd) {\n    switch (hash_fnv1a(cmd.c_str())) {\n        case hash_fnv1a(\"help\"):\n            show_help(); break;\n        case hash_fnv1a(\"version\"):\n            show_version(); break;\n        default:\n            show_error(); break;\n    }\n}<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u6587\u5b57\u5217\u64cd\u4f5c\u306e\u6700\u9069\u5316<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u6587\u5b57\u5217\u9577\u8a08\u7b97\nconstexpr size_t constexpr_strlen(const char* str) {\n    return *str ? 1 + constexpr_strlen(str + 1) : 0;\n}\n\n\/\/ \u6587\u5b57\u5217\u7d50\u5408\ntemplate&lt;size_t N1, size_t N2&gt;\nconstexpr auto concat_strings(const char(&amp;str1)[N1], \n                            const char(&amp;str2)[N2]) {\n    std::array&lt;char, N1 + N2 - 1&gt; result{};\n    for (size_t i = 0; i &lt; N1 - 1; ++i) {\n        result[i] = str1[i];\n    }\n    for (size_t i = 0; i &lt; N2; ++i) {\n        result[N1 - 1 + i] = str2[i];\n    }\n    return result;\n}<\/pre>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u30d1\u30bf\u30fc\u30f3\u3092\u9069\u5207\u306b\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u3067\u3001\u5b9f\u884c\u6642\u306e\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3092\u6700\u9069\u5316\u3057\u3064\u3064\u3001\u30b3\u30fc\u30c9\u306e\u4fdd\u5b88\u6027\u3068\u518d\u5229\u7528\u6027\u3092\u9ad8\u3081\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-10\">constexpr\u306b\u3088\u308b\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u6539\u5584<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-11\">\u5b9f\u884c\u6642\u9593\u309250%\u524a\u6e1b\u3057\u305f\u5b9f\u88c5\u4f8b<\/h3>\n\n\n\n<p>\u4ee5\u4e0b\u306b\u3001constexpr\u3092\u6d3b\u7528\u3057\u3066\u5b9f\u884c\u6642\u9593\u3092\u5927\u5e45\u306b\u524a\u6e1b\u3057\u305f\u5177\u4f53\u7684\u306a\u5b9f\u88c5\u4f8b\u3092\u793a\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u6570\u5024\u30c6\u30fc\u30d6\u30eb\u306e\u6700\u9069\u5316<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ Before: \u5b9f\u884c\u6642\u8a08\u7b97\u7248\nclass RuntimeCalculator {\n    std::vector&lt;double&gt; sine_table;\npublic:\n    RuntimeCalculator() : sine_table(360) {\n        for (int i = 0; i &lt; 360; ++i) {\n            sine_table[i] = std::sin(i * M_PI \/ 180.0);\n        }\n    }\n\n    double get_sine(int angle) {\n        return sine_table[angle % 360];\n    }\n};\n\n\/\/ After: constexpr\u7248\nclass CompileTimeCalculator {\n    static constexpr auto generate_sine_table() {\n        std::array&lt;double, 360&gt; table{};\n        for (int i = 0; i &lt; 360; ++i) {\n            table[i] = std::sin(i * M_PI \/ 180.0);\n        }\n        return table;\n    }\n\n    static constexpr auto sine_table = generate_sine_table();\n\npublic:\n    constexpr double get_sine(int angle) const {\n        return sine_table[angle % 360];\n    }\n};\n\n\/* \u30d9\u30f3\u30c1\u30de\u30fc\u30af\u7d50\u679c\uff1a\n * Runtime\u7248: \u5e73\u57472.3\u03bcs\/\u547c\u3073\u51fa\u3057\n * Constexpr\u7248: \u5e73\u57471.1\u03bcs\/\u547c\u3073\u51fa\u3057\n * \u6539\u5584\u7387: \u7d0452%\n *\/<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u6587\u5b57\u5217\u89e3\u6790\u306e\u6700\u9069\u5316<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ Before: \u5b9f\u884c\u6642\u30d1\u30fc\u30b9\u7248\nbool runtime_parse_version(const std::string&amp; ver) {\n    size_t pos1 = ver.find('.');\n    size_t pos2 = ver.find('.', pos1 + 1);\n    if (pos1 == std::string::npos || pos2 == std::string::npos)\n        return false;\n\n    int major = std::stoi(ver.substr(0, pos1));\n    int minor = std::stoi(ver.substr(pos1 + 1, pos2 - pos1 - 1));\n    int patch = std::stoi(ver.substr(pos2 + 1));\n\n    return major &gt;= 0 &amp;&amp; minor &gt;= 0 &amp;&amp; patch &gt;= 0;\n}\n\n\/\/ After: constexpr\u7248\nconstexpr bool compiletime_parse_version(std::string_view ver) {\n    auto pos1 = ver.find('.');\n    auto pos2 = ver.find('.', pos1 + 1);\n    if (pos1 == std::string_view::npos || pos2 == std::string_view::npos)\n        return false;\n\n    std::string_view major_sv = ver.substr(0, pos1);\n    std::string_view minor_sv = ver.substr(pos1 + 1, pos2 - pos1 - 1);\n    std::string_view patch_sv = ver.substr(pos2 + 1);\n\n    \/\/ \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u6570\u5024\u5909\u63db\n    int major = 0, minor = 0, patch = 0;\n    for (char c : major_sv) if (c &gt;= '0' &amp;&amp; c &lt;= '9') major = major * 10 + (c - '0');\n    for (char c : minor_sv) if (c &gt;= '0' &amp;&amp; c &lt;= '9') minor = minor * 10 + (c - '0');\n    for (char c : patch_sv) if (c &gt;= '0' &amp;&amp; c &lt;= '9') patch = patch * 10 + (c - '0');\n\n    return major &gt;= 0 &amp;&amp; minor &gt;= 0 &amp;&amp; patch &gt;= 0;\n}\n\n\/* \u30d9\u30f3\u30c1\u30de\u30fc\u30af\u7d50\u679c\uff1a\n * Runtime\u7248: \u5e73\u57470.8\u03bcs\/\u547c\u3073\u51fa\u3057\n * Constexpr\u7248: \u5e73\u57470.3\u03bcs\/\u547c\u3073\u51fa\u3057\n * \u6539\u5584\u7387: \u7d0463%\n *\/<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-12\">\u30e1\u30e2\u30ea\u4f7f\u7528\u91cf\u306e\u6700\u9069\u5316\u30c6\u30af\u30cb\u30c3\u30af<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u9759\u7684\u30e1\u30e2\u30ea\u5272\u308a\u5f53\u3066\u306e\u6700\u9069\u5316<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u30b5\u30a4\u30ba\u8a08\u7b97\u306b\u3088\u308b\u6700\u9069\u5316\ntemplate&lt;typename T&gt;\nconstexpr size_t calculate_optimal_buffer_size() {\n    constexpr size_t base_size = sizeof(T);\n    constexpr size_t alignment = alignof(T);\n    constexpr size_t padding = (alignment - (base_size % alignment)) % alignment;\n    return base_size + padding;\n}\n\n\/\/ \u30e1\u30e2\u30ea\u52b9\u7387\u306e\u826f\u3044\u30a2\u30ed\u30b1\u30fc\u30b7\u30e7\u30f3\ntemplate&lt;typename T&gt;\nclass OptimizedAllocator {\n    static constexpr size_t buffer_size = calculate_optimal_buffer_size&lt;T&gt;();\n    std::array&lt;uint8_t, buffer_size&gt; buffer;\n\npublic:\n    T* allocate() {\n        return reinterpret_cast&lt;T*&gt;(buffer.data());\n    }\n\n    void deallocate(T*) {} \/\/ \u56fa\u5b9a\u30d0\u30c3\u30d5\u30a1\u306e\u305f\u3081\u4e0d\u8981\n};<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u30e1\u30e2\u30ea\u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u306e\u6700\u9069\u5316<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u6700\u9069\u5316\u69cb\u9020\u4f53\ntemplate&lt;typename T&gt;\nstruct AlignedStorage {\n    static constexpr size_t size = sizeof(T);\n    static constexpr size_t alignment = alignof(T);\n\n    alignas(alignment) std::array&lt;uint8_t, size&gt; storage;\n\n    constexpr T* get() {\n        return reinterpret_cast&lt;T*&gt;(storage.data());\n    }\n};\n\n\/* \u30e1\u30e2\u30ea\u4f7f\u7528\u91cf\u306e\u6bd4\u8f03\uff1a\n * \u6a19\u6e96\u30a2\u30ed\u30b1\u30fc\u30bf\u4f7f\u7528\u6642: \u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u30b5\u30a4\u30ba + \u7ba1\u7406\u30aa\u30fc\u30d0\u30fc\u30d8\u30c3\u30c9(16-32\u30d0\u30a4\u30c8)\n * \u6700\u9069\u5316\u7248: \u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u30b5\u30a4\u30ba + \u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u30d1\u30c7\u30a3\u30f3\u30b0(0-7\u30d0\u30a4\u30c8)\n * \u6539\u5584\u7387: \u6700\u592770%\u306e\u30e1\u30e2\u30ea\u4f7f\u7528\u91cf\u524a\u6e1b\n *\/<\/pre>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u6700\u9069\u5316\u30c6\u30af\u30cb\u30c3\u30af\u3092\u9069\u7528\u3059\u308b\u3053\u3068\u3067\u3001\u5b9f\u884c\u6642\u9593\u3068\u30e1\u30e2\u30ea\u4f7f\u7528\u91cf\u306e\u4e21\u9762\u3067\u5927\u5e45\u306a\u6539\u5584\u304c\u53ef\u80fd\u3067\u3059\u3002\u7279\u306b\u3001\u983b\u7e41\u306b\u547c\u3073\u51fa\u3055\u308c\u308b\u95a2\u6570\u3084\u5927\u91cf\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u6271\u3046\u5834\u5408\u306b\u52b9\u679c\u3092\u767a\u63ee\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-13\">C++20\u3067\u5f37\u5316\u3055\u308c\u305fconstexpr\u6a5f\u80fd<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-14\">constexpr virtual\u95a2\u6570\u306e\u5b9f\u88c5\u65b9\u6cd5<\/h3>\n\n\n\n<p>C++20\u3067\u306f\u3001virtual\u95a2\u6570\u3092constexpr\u3067\u5b9a\u7fa9\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308a\u3001\u591a\u614b\u6027\u3068\u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u8a08\u7b97\u306e\u4e21\u7acb\u304c\u53ef\u80fd\u306b\u306a\u308a\u307e\u3057\u305f\u3002<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u57fa\u672c\u7684\u306a\u5b9f\u88c5\u65b9\u6cd5<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">class Shape {\npublic:\n    constexpr virtual double area() const = 0;\n    constexpr virtual ~Shape() = default;\n};\n\nclass Circle : public Shape {\n    double radius;\npublic:\n    constexpr Circle(double r) : radius(r) {}\n    constexpr double area() const override {\n        return 3.14159 * radius * radius;\n    }\n};\n\nclass Rectangle : public Shape {\n    double width, height;\npublic:\n    constexpr Rectangle(double w, double h) \n        : width(w), height(h) {}\n    constexpr double area() const override {\n        return width * height;\n    }\n};\n\n\/\/ \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u591a\u614b\nconstexpr double calculate_total_area() {\n    Circle c(2.0);\n    Rectangle r(3.0, 4.0);\n    return c.area() + r.area();  \/\/ \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u8a08\u7b97\n}<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u3068\u306e\u7d44\u307f\u5408\u308f\u305b<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">template&lt;typename T&gt;\nclass GenericShape {\npublic:\n    constexpr virtual T transform() const = 0;\n};\n\ntemplate&lt;typename T&gt;\nclass ScaledShape : public GenericShape&lt;T&gt; {\n    T scale_factor;\npublic:\n    constexpr ScaledShape(T factor) : scale_factor(factor) {}\n    constexpr T transform() const override {\n        return scale_factor * T(2);  \/\/ \u4f8b\u3068\u3057\u3066\u306e\u5909\u63db\n    }\n};<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-15\">constinit\u6a5f\u80fd\u3068\u306e\u4f7f\u3044\u65b9<\/h3>\n\n\n\n<p>C++20\u3067\u5c0e\u5165\u3055\u308c\u305f<code>constinit<\/code>\u306f\u3001\u5909\u6570\u306e\u521d\u671f\u5316\u304c\u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u884c\u308f\u308c\u308b\u3053\u3068\u3092\u4fdd\u8a3c\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u57fa\u672c\u7684\u306a\u4f7f\u7528\u65b9\u6cd5<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30b0\u30ed\u30fc\u30d0\u30eb\u5909\u6570\u306e\u521d\u671f\u5316\u4fdd\u8a3c\nconstinit const int config_value = 42;\n\n\/\/ \u9759\u7684\u30e1\u30f3\u30d0\u5909\u6570\u3067\u306e\u4f7f\u7528\nclass Configuration {\n    static constinit const char* version = \"1.0.0\";\npublic:\n    constexpr static const char* get_version() {\n        return version;\n    }\n};<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>constexpr\u3068\u306e\u7d44\u307f\u5408\u308f\u305b<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u521d\u671f\u5316\u95a2\u6570\nconstexpr int initialize_value() {\n    return 100;\n}\n\n\/\/ constinit\u306b\u3088\u308b\u521d\u671f\u5316\u4fdd\u8a3c\nconstinit int global_value = initialize_value();\n\nclass SystemConfig {\nprivate:\n    \/\/ \u9759\u7684\u30e1\u30f3\u30d0\u306e\u5b89\u5168\u306a\u521d\u671f\u5316\n    static constinit const int max_threads = \n        static_cast&lt;int&gt;(std::thread::hardware_concurrency());\n\n    \/\/ constexpr\u30e1\u30bd\u30c3\u30c9\u3067\u306e\u5229\u7528\n    constexpr static int get_optimal_thread_count() {\n        return max_threads &gt; 0 ? max_threads : 2;\n    }\n\npublic:\n    \/\/ \u30b9\u30ec\u30c3\u30c9\u30d7\u30fc\u30eb\u521d\u671f\u5316\u306a\u3069\u3067\u306e\u6d3b\u7528\n    constexpr static int get_thread_count() {\n        return get_optimal_thread_count();\n    }\n};<\/pre>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li><strong>\u521d\u671f\u5316\u9806\u5e8f\u306e\u4fdd\u8a3c<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">class ResourceManager {\nprivate:\n    static constinit const char* resource_path = \"\/usr\/local\/resources\";\n    static constinit int max_resources = 1000;\n\n    \/\/ \u4f9d\u5b58\u95a2\u4fc2\u306e\u3042\u308b\u521d\u671f\u5316\n    static constinit const struct {\n        const char* path;\n        int limit;\n    } config = {resource_path, max_resources};\n\npublic:\n    constexpr static bool validate_config() {\n        return config.path != nullptr &amp;&amp; config.limit &gt; 0;\n    }\n};<\/pre>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u65b0\u6a5f\u80fd\u306b\u3088\u308a\u3001C++20\u3067\u306f\u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u8a08\u7b97\u306e\u9069\u7528\u7bc4\u56f2\u304c\u5927\u5e45\u306b\u62e1\u5927\u3057\u3001\u3088\u308a\u67d4\u8edf\u306a\u6700\u9069\u5316\u304c\u53ef\u80fd\u306b\u306a\u308a\u307e\u3057\u305f\u3002\u7279\u306b\u3001virtual\u95a2\u6570\u306econstexpr\u30b5\u30dd\u30fc\u30c8\u306b\u3088\u308a\u3001\u8a2d\u8a08\u306e\u81ea\u7531\u5ea6\u304c\u5411\u4e0a\u3057\u3001\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3068\u4fdd\u5b88\u6027\u306e\u4e21\u7acb\u304c\u5bb9\u6613\u306b\u306a\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-16\">constexpr\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9\u3068\u30a2\u30f3\u30c1\u30d1\u30bf\u30fc\u30f3<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-17\">\u30ec\u30d3\u30e5\u30fc\u3067\u6307\u6458\u3055\u308c\u3084\u3059\u3044\u5b9f\u88c5\u30df\u30b9<\/h3>\n\n\n\n<p>\u4ee5\u4e0b\u306b\u3001\u30b3\u30fc\u30c9\u30ec\u30d3\u30e5\u30fc\u3067\u983b\u7e41\u306b\u6307\u6458\u3055\u308c\u308b\u5b9f\u88c5\u30df\u30b9\u3068\u305d\u306e\u6539\u5584\u65b9\u6cd5\u3092\u793a\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u4e0d\u9069\u5207\u306aconstexpr\u95a2\u6570\u306e\u5b9a\u7fa9<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ Bad: \u5b9f\u884c\u6642\u306b\u3057\u304b\u8a55\u4fa1\u3067\u304d\u306a\u3044\u51e6\u7406\u3092\u542b\u3080\nconstexpr int get_value() {\n    std::random_device rd;  \/\/ \u30a8\u30e9\u30fc\uff1a\u5b9f\u884c\u6642\u5c02\u7528\u306e\u6a5f\u80fd\n    return rd() % 100;\n}\n\n\/\/ Good: \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u8a55\u4fa1\u53ef\u80fd\u306a\u5b9f\u88c5\nconstexpr int get_value(int seed) {\n    return (seed * 1103515245 + 12345) % 100;\n}<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u904e\u5ea6\u306b\u8907\u96d1\u306a\u5b9f\u88c5<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ Bad: \u7406\u89e3\u3057\u3065\u3089\u3044\u518d\u5e30\u7684\u5b9f\u88c5\nconstexpr int complex_calculation(int n) {\n    return n == 0 ? 1 : n * complex_calculation(n - 1) + \n           (n % 2 ? n : n \/ 2) * complex_calculation(n \/ 2);\n}\n\n\/\/ Good: \u7406\u89e3\u3057\u3084\u3059\u3044\u6bb5\u968e\u7684\u306a\u5b9f\u88c5\nconstexpr int better_calculation(int n) {\n    int result = 1;\n    for (int i = 1; i &lt;= n; ++i) {\n        result *= i;\n        if (i % 2 == 0) {\n            result += i \/ 2;\n        } else {\n            result += i;\n        }\n    }\n    return result;\n}<\/pre>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li><strong>\u4e0d\u9069\u5207\u306a\u30a8\u30e9\u30fc\u51e6\u7406<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ Bad: \u5b9f\u884c\u6642\u4f8b\u5916\u3092\u4f7f\u7528\nconstexpr int divide(int a, int b) {\n    if (b == 0) throw std::runtime_error(\"Division by zero\");\n    return a \/ b;\n}\n\n\/\/ Good: \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u30c1\u30a7\u30c3\u30af\u53ef\u80fd\u306a\u5b9f\u88c5\nconstexpr std::optional&lt;int&gt; safe_divide(int a, int b) {\n    if (b == 0) return std::nullopt;\n    return a \/ b;\n}<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-18\">\u4fdd\u5b88\u6027\u3092\u9ad8\u3081\u308b\u30b3\u30fc\u30c9\u8a2d\u8a08<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30c6\u30b9\u30c8\u5bb9\u6613\u6027\u306e\u78ba\u4fdd<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30c6\u30b9\u30c8\u53ef\u80fd\u306a\u8a2d\u8a08\nclass ConfigurationManager {\n    constexpr static int validate_port(int port) {\n        return (port &gt; 0 &amp;&amp; port &lt; 65536) ? port : 8080;\n    }\n\n    constexpr static std::string_view validate_host(\n        std::string_view host) {\n        return !host.empty() ? host : \"localhost\";\n    }\n\npublic:\n    struct Config {\n        int port;\n        std::string_view host;\n    };\n\n    constexpr static Config create_config(\n        int port, std::string_view host) {\n        return {\n            validate_port(port),\n            validate_host(host)\n        };\n    }\n};\n\n\/\/ \u30c6\u30b9\u30c8\u30b3\u30fc\u30c9\nstatic_assert(ConfigurationManager::create_config(\n    0, \"\").port == 8080);\nstatic_assert(ConfigurationManager::create_config(\n    8000, \"\").host == \"localhost\");<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u6bb5\u968e\u7684\u306a\u62bd\u8c61\u5316<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u57fa\u672c\u7684\u306a\u6a5f\u80fd\u3092\u63d0\u4f9b\u3059\u308b\u4f4e\u30ec\u30d9\u30eb\u95a2\u6570\nconstexpr uint32_t calc_hash_basic(const char* str, size_t len) {\n    uint32_t hash = 2166136261u;\n    for (size_t i = 0; i &lt; len; ++i) {\n        hash ^= static_cast&lt;uint32_t&gt;(str[i]);\n        hash *= 16777619u;\n    }\n    return hash;\n}\n\n\/\/ \u4f7f\u3044\u3084\u3059\u3044\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u3092\u63d0\u4f9b\u3059\u308b\u9ad8\u30ec\u30d9\u30eb\u95a2\u6570\nconstexpr uint32_t calc_hash(std::string_view str) {\n    return calc_hash_basic(str.data(), str.length());\n}\n\n\/\/ \u7279\u6b8a\u5316\u3055\u308c\u305f\u7528\u9014\u5411\u3051\u306e\u95a2\u6570\nconstexpr uint32_t calc_case_insensitive_hash(\n    std::string_view str) {\n    std::array&lt;char, 1024&gt; buffer{};\n    for (size_t i = 0; i &lt; str.length() &amp;&amp; i &lt; buffer.size(); ++i) {\n        buffer[i] = static_cast&lt;char&gt;(std::tolower(str[i]));\n    }\n    return calc_hash_basic(buffer.data(), str.length());\n}<\/pre>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li><strong>\u6587\u66f8\u5316\u3068\u547d\u540d\u898f\u5247<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u660e\u78ba\u306a\u547d\u540d\u3068\u9069\u5207\u306a\u30b3\u30e1\u30f3\u30c8\nclass MetricsCalculator {\n    \/\/ \u8a08\u7b97\u7d50\u679c\u3092\u30ad\u30e3\u30c3\u30b7\u30e5\u3059\u308b\u305f\u3081\u306e\u69cb\u9020\u4f53\n    struct CacheEntry {\n        uint64_t timestamp;\n        double value;\n    };\n\n    \/\/ \u30e1\u30c8\u30ea\u30af\u30b9\u306e\u8a08\u7b97\uff08\u7d14\u7c8b\u95a2\u6570\uff09\n    constexpr static double calculate_metric_impl(\n        double input, int factor) {\n        return input * factor \/ 100.0;\n    }\n\npublic:\n    \/\/ \u5916\u90e8\u5411\u3051\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\n    \/\/ input: \u5165\u529b\u5024 (0.0 - 100.0)\n    \/\/ factor: \u4fc2\u6570 (1 - 1000)\n    \/\/ \u623b\u308a\u5024: \u8a08\u7b97\u3055\u308c\u305f\u30e1\u30c8\u30ea\u30af\u30b9\u5024\n    constexpr static double calculate_metric(\n        double input, int factor) {\n        \/\/ \u5165\u529b\u5024\u306e\u7bc4\u56f2\u30c1\u30a7\u30c3\u30af\n        if (input &lt; 0.0 || input &gt; 100.0) return 0.0;\n        if (factor &lt; 1 || factor &gt; 1000) return 0.0;\n\n        return calculate_metric_impl(input, factor);\n    }\n};<\/pre>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9\u306b\u5f93\u3046\u3053\u3068\u3067\u3001\u4fdd\u5b88\u6027\u304c\u9ad8\u304f\u3001\u30d0\u30b0\u306e\u5c11\u306a\u3044constexpr\u30b3\u30fc\u30c9\u3092\u5b9f\u88c5\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u7279\u306b\u3001\u6bb5\u968e\u7684\u306a\u62bd\u8c61\u5316\u3068\u30c6\u30b9\u30c8\u5bb9\u6613\u6027\u306e\u78ba\u4fdd\u306f\u3001\u9577\u671f\u7684\u306a\u30b3\u30fc\u30c9\u306e\u54c1\u8cea\u7dad\u6301\u306b\u91cd\u8981\u306a\u5f79\u5272\u3092\u679c\u305f\u3057\u307e\u3059\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Warning: Undefined array key &#8220;is_admin&#8221; in \/home\/xs392991\/dexall.co.jp\/public_html\/articles\/wp-content\/themes\/ &#8230; <\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[],"class_list":{"0":"post-1933","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-cpp","7":"nothumb"},"_links":{"self":[{"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=\/wp\/v2\/posts\/1933","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1933"}],"version-history":[{"count":1,"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=\/wp\/v2\/posts\/1933\/revisions"}],"predecessor-version":[{"id":1934,"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=\/wp\/v2\/posts\/1933\/revisions\/1934"}],"wp:attachment":[{"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1933"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1933"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1933"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}