{"id":1954,"date":"2025-03-24T08:49:31","date_gmt":"2025-03-23T23:49:31","guid":{"rendered":"https:\/\/dexall.co.jp\/articles\/?p=1954"},"modified":"2025-03-24T08:49:31","modified_gmt":"2025-03-23T23:49:31","slug":"c-union%e3%82%92%e5%ae%8c%e5%85%a8%e7%90%86%e8%a7%a3%ef%bc%81%e3%83%a1%e3%83%a2%e3%83%aa%e5%8a%b9%e7%8e%87%e5%8c%96%e3%81%a8%e3%83%90%e3%82%b0%e5%9b%9e%e9%81%bf%e3%81%ae%e5%ae%9f%e8%b7%b5%e7%9a%84","status":"publish","type":"post","link":"https:\/\/dexall.co.jp\/articles\/?p=1954","title":{"rendered":"C++ union\u3092\u5b8c\u5168\u7406\u89e3\uff01\u30e1\u30e2\u30ea\u52b9\u7387\u5316\u3068\u30d0\u30b0\u56de\u907f\u306e\u5b9f\u8df5\u7684\u6d3b\u7528\u6cd57\u9078"},"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\">C++ union\u3068\u306f\uff1a\u30e1\u30e2\u30ea\u52b9\u7387\u5316\u306e\u5f37\u529b\u306a\u6b66\u5668<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-1\">1\u3064\u306e\u30e1\u30e2\u30ea\u9818\u57df\u3092\u8907\u6570\u306e\u578b\u3067\u5171\u6709\u3067\u304d\u308b\u7279\u6b8a\u306a\u30c7\u30fc\u30bf\u69cb\u9020<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-2\">\u69cb\u9020\u4f53\uff08struct\uff09\u3068\u306e\u91cd\u8981\u306a\u9055\u3044\u3068\u7279\u5fb4<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-3\">union\u306e\u30e1\u30e2\u30ea\u52b9\u7387\u5316\u30e1\u30ab\u30cb\u30ba\u30e0<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-4\">\u30e1\u30e2\u30ea\u4f7f\u7528\u91cf\u3092\u6700\u5c0f\u9650\u306b\u6291\u3048\u308b\u4ed5\u7d44\u307f<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-5\">\u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u3068\u30d1\u30c7\u30a3\u30f3\u30b0\u306e\u6700\u9069\u5316\u65b9\u6cd5<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-6\">\u5b9f\u8df5\u7684\u306aunion\u306e\u6d3b\u7528\u6cd57\u9078<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-7\">\u30d0\u30a4\u30c8\u914d\u5217\u3068\u6570\u5024\u578b\u306e\u76f8\u4e92\u5909\u63db\u30c6\u30af\u30cb\u30c3\u30af<\/a>      <\/li>      <li>        <a href=\"#i-8\">\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u30d7\u30ed\u30c8\u30b3\u30eb\u306e\u30d1\u30b1\u30c3\u30c8\u51e6\u7406\u306e\u52b9\u7387\u5316<\/a>      <\/li>      <li>        <a href=\"#i-9\">\u30e1\u30e2\u30ea\u30de\u30c3\u30d7\u30c9IO\u306e\u5b9f\u88c5\u65b9\u6cd5<\/a>      <\/li>      <li>        <a href=\"#i-10\">\u578b\u306e\u5171\u7528\u306b\u3088\u308b\u30e1\u30e2\u30ea\u7bc0\u7d04\u30d1\u30bf\u30fc\u30f3<\/a>      <\/li>      <li>        <a href=\"#i-11\">\u30b9\u30c6\u30fc\u30c8\u30de\u30b7\u30f3\u306e\u52b9\u7387\u7684\u306a\u5b9f\u88c5<\/a>      <\/li>      <li>        <a href=\"#i-12\">\u53ef\u5909\u578b\u306e\u5b9f\u88c5\u306b\u3088\u308b\u30a4\u30f3\u30bf\u30d5\u30a7\u30fc\u30b9\u306e\u67d4\u8edf\u5316<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-13\">\u30d3\u30c3\u30c8\u30d5\u30a3\u30fc\u30eb\u30c9\u3068\u306e\u7d44\u307f\u5408\u308f\u305b\u30c6\u30af\u30cb\u30c3\u30af<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-14\">union\u3092\u4f7f\u7528\u3059\u308b\u969b\u306e\u6ce8\u610f\u70b9\u3068\u5bfe\u7b56<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-15\">\u578b\u306e\u5b89\u5168\u6027\u3092\u78ba\u4fdd\u3059\u308b\u305f\u3081\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-16\">\u672a\u5b9a\u7fa9\u52d5\u4f5c\u3092\u907f\u3051\u308b\u305f\u3081\u306e\u5177\u4f53\u7684\u306a\u65b9\u6cd5<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-17\">C++17\u4ee5\u964d\u306eunion\u306e\u65b0\u6a5f\u80fd\u3068\u6539\u5584\u70b9<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-18\">\u53ef\u5909\u5f15\u6570\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u3068\u306e\u89aa\u548c\u6027\u5411\u4e0a<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-19\">\u69cb\u9020\u5316\u675f\u7e1b\u306b\u3088\u308b\u30a2\u30af\u30bb\u30b9\u6027\u306e\u5411\u4e0a<\/a>      <\/li>    <\/ul>  <\/li>  <li class=\"last\">    <a href=\"#i-20\">union\u306e\u5b9f\u8df5\u7684\u306a\u4ee3\u66ff\u624b\u6bb5\u3068\u4f7f\u3044\u5206\u3051<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-21\">std::variant\u3068\u306e\u6bd4\u8f03\u3068\u9069\u5207\u306a\u9078\u629e\u57fa\u6e96<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-22\">\u578b\u5b89\u5168\u306aunion\u306e\u5b9f\u88c5\u30d1\u30bf\u30fc\u30f3<\/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\">C++ union\u3068\u306f\uff1a\u30e1\u30e2\u30ea\u52b9\u7387\u5316\u306e\u5f37\u529b\u306a\u6b66\u5668<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-1\">1\u3064\u306e\u30e1\u30e2\u30ea\u9818\u57df\u3092\u8907\u6570\u306e\u578b\u3067\u5171\u6709\u3067\u304d\u308b\u7279\u6b8a\u306a\u30c7\u30fc\u30bf\u69cb\u9020<\/h3>\n\n\n\n<p>C++\u306eunion\u306f\u3001\u8907\u6570\u306e\u7570\u306a\u308b\u30c7\u30fc\u30bf\u578b\u306e\u30e1\u30f3\u30d0\u30fc\u304c\u540c\u4e00\u306e\u30e1\u30e2\u30ea\u9818\u57df\u3092\u5171\u6709\u3059\u308b\u7279\u6b8a\u306a\u30c7\u30fc\u30bf\u69cb\u9020\u3067\u3059\u3002\u30e1\u30e2\u30ea\u306e\u52b9\u7387\u7684\u306a\u4f7f\u7528\u304c\u6c42\u3081\u3089\u308c\u308b\u5834\u9762\u3067\u5f37\u529b\u306a\u6b66\u5668\u3068\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u4ee5\u4e0b\u306e\u30b3\u30fc\u30c9\u4f8b\u3067\u3001union\u306e\u57fa\u672c\u7684\u306a\u4f7f\u3044\u65b9\u3092\u898b\u3066\u307f\u307e\u3057\u3087\u3046\uff1a<\/p>\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=\"\">union DataConverter {\n    uint32_t integer;     \/\/ 4\u30d0\u30a4\u30c8\n    float floating;       \/\/ 4\u30d0\u30a4\u30c8\n    uint8_t bytes[4];     \/\/ 4\u30d0\u30a4\u30c8\n};\n\nint main() {\n    DataConverter converter;\n\n    \/\/ \u6574\u6570\u5024\u3068\u3057\u306632bit\u30c7\u30fc\u30bf\u3092\u8a2d\u5b9a\n    converter.integer = 0x12345678;\n\n    \/\/ \u540c\u3058\u30e1\u30e2\u30ea\u9818\u57df\u3092\u7570\u306a\u308b\u578b\u3068\u3057\u3066\u89e3\u91c8\n    float f = converter.floating;\n\n    \/\/ \u30d0\u30a4\u30c8\u914d\u5217\u3068\u3057\u3066\u30a2\u30af\u30bb\u30b9\n    for(int i = 0; i &lt; 4; ++i) {\n        printf(\"%02X \", converter.bytes[i]);  \/\/ \u30e1\u30e2\u30ea\u306e\u5185\u5bb9\u3092\u30d0\u30a4\u30c8\u5358\u4f4d\u3067\u8868\u793a\n    }\n    return 0;\n}<\/pre>\n\n\n\n<p>\u3053\u306e\u30b3\u30fc\u30c9\u3067\u306f\u3001<code>DataConverter<\/code> union\u304c4\u30d0\u30a4\u30c8\u306e\u30e1\u30e2\u30ea\u9818\u57df\u3092\u3001\u6574\u6570\u578b\u3001\u6d6e\u52d5\u5c0f\u6570\u70b9\u578b\u3001\u30d0\u30a4\u30c8\u914d\u5217\u3068\u3057\u3066\u7570\u306a\u308b\u65b9\u6cd5\u3067\u30a2\u30af\u30bb\u30b9\u3067\u304d\u308b\u3088\u3046\u306b\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-2\">\u69cb\u9020\u4f53\uff08struct\uff09\u3068\u306e\u91cd\u8981\u306a\u9055\u3044\u3068\u7279\u5fb4<\/h3>\n\n\n\n<p>union\u3068\u69cb\u9020\u4f53\uff08struct\uff09\u306e\u4e3b\u306a\u9055\u3044\u306f\u3001\u30e1\u30e2\u30ea\u306e\u4f7f\u7528\u65b9\u6cd5\u306b\u3042\u308a\u307e\u3059\u3002\u4ee5\u4e0b\u306e\u6bd4\u8f03\u3067\u5177\u4f53\u7684\u306b\u898b\u3066\u307f\u307e\u3057\u3087\u3046\uff1a<\/p>\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=\"\">\/\/ struct\u306e\u5834\u5408\nstruct DataStruct {\n    uint32_t integer;     \/\/ 4\u30d0\u30a4\u30c8\n    float floating;       \/\/ 4\u30d0\u30a4\u30c8\n    uint8_t bytes[4];     \/\/ 4\u30d0\u30a4\u30c8\n};  \/\/ \u5408\u8a0812\u30d0\u30a4\u30c8\n\n\/\/ union\u306e\u5834\u5408\nunion DataUnion {\n    uint32_t integer;     \/\/ 4\u30d0\u30a4\u30c8\n    float floating;       \/\/ 4\u30d0\u30a4\u30c8\n    uint8_t bytes[4];     \/\/ 4\u30d0\u30a4\u30c8\n};  \/\/ \u5408\u8a084\u30d0\u30a4\u30c8\uff08\u6700\u5927\u306e\u30e1\u30f3\u30d0\u30fc\u306e\u30b5\u30a4\u30ba\uff09<\/pre>\n\n\n\n<p>\u4e3b\u306a\u7279\u5fb4\u306e\u6bd4\u8f03\uff1a<\/p>\n\n\n<div id=\"id-becf4b35-05b1-44e0-88d6-4f39895fe2ca\">\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u7279\u5fb4<\/th><th>union<\/th><th>struct<\/th><\/tr><\/thead><tbody><tr><td>\u30e1\u30e2\u30ea\u4f7f\u7528<\/td><td>\u6700\u5927\u30e1\u30f3\u30d0\u30fc\u306e\u30b5\u30a4\u30ba<\/td><td>\u5168\u30e1\u30f3\u30d0\u30fc\u306e\u5408\u8a08\u30b5\u30a4\u30ba<\/td><\/tr><tr><td>\u540c\u6642\u30a2\u30af\u30bb\u30b9<\/td><td>1\u3064\u306e\u30e1\u30f3\u30d0\u30fc\u306e\u307f\u6709\u52b9<\/td><td>\u5168\u30e1\u30f3\u30d0\u30fc\u306b\u540c\u6642\u30a2\u30af\u30bb\u30b9\u53ef\u80fd<\/td><\/tr><tr><td>\u30e1\u30e2\u30ea\u914d\u7f6e<\/td><td>\u30e1\u30f3\u30d0\u30fc\u304c\u540c\u3058\u30a2\u30c9\u30ec\u30b9\u3092\u5171\u6709<\/td><td>\u30e1\u30f3\u30d0\u30fc\u304c\u9806\u756a\u306b\u914d\u7f6e<\/td><\/tr><tr><td>\u4e3b\u306a\u7528\u9014<\/td><td>\u30e1\u30e2\u30ea\u52b9\u7387\u5316\u3001\u578b\u5909\u63db<\/td><td>\u30c7\u30fc\u30bf\u306e\u8ad6\u7406\u7684\u306a\u30b0\u30eb\u30fc\u30d7\u5316<\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n\n\n<p>union\u306e\u6d3b\u7528\u30b7\u30fc\u30f3\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30e1\u30e2\u30ea\u52b9\u7387\u5316\u304c\u5fc5\u8981\u306a\u5834\u9762<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u7d44\u307f\u8fbc\u307f\u30b7\u30b9\u30c6\u30e0<\/li>\n\n\n\n<li>\u30e1\u30e2\u30ea\u5236\u7d04\u306e\u53b3\u3057\u3044\u74b0\u5883<\/li>\n\n\n\n<li>\u5927\u91cf\u306e\u30c7\u30fc\u30bf\u51e6\u7406<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30c7\u30fc\u30bf\u306e\u7570\u306a\u308b\u89e3\u91c8\u304c\u5fc5\u8981\u306a\u5834\u9762<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30d0\u30a4\u30ca\u30ea\u30c7\u30fc\u30bf\u306e\u89e3\u6790<\/li>\n\n\n\n<li>\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u30d7\u30ed\u30c8\u30b3\u30eb\u306e\u5b9f\u88c5<\/li>\n\n\n\n<li>\u30cf\u30fc\u30c9\u30a6\u30a7\u30a2\u30ec\u30b8\u30b9\u30bf\u306e\u30a2\u30af\u30bb\u30b9<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u578b\u5909\u63db\u304c\u5fc5\u8981\u306a\u5834\u9762<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30d3\u30c3\u30c8\u64cd\u4f5c<\/li>\n\n\n\n<li>\u30a8\u30f3\u30c7\u30a3\u30a2\u30f3\u5909\u63db<\/li>\n\n\n\n<li>\u6570\u5024\u5f62\u5f0f\u306e\u5909\u63db<\/li>\n<\/ul>\n\n\n\n<p>\u6ce8\u610f\u70b9\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>union\u306e\u30e1\u30f3\u30d0\u30fc\u30a2\u30af\u30bb\u30b9\u306b\u306f\u9069\u5207\u306a\u578b\u306e\u4f7f\u7528\u304c\u91cd\u8981<\/li>\n\n\n\n<li>\u7570\u306a\u308b\u578b\u9593\u3067\u306e\u5909\u63db\u6642\u306b\u306f\u3001\u30e1\u30e2\u30ea\u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u306b\u6ce8\u610f<\/li>\n\n\n\n<li>\u5b9f\u884c\u74b0\u5883\u306b\u3088\u3063\u3066\u30d0\u30a4\u30c8\u30aa\u30fc\u30c0\u30fc\u304c\u7570\u306a\u308b\u53ef\u80fd\u6027\u306b\u7559\u610f<\/li>\n<\/ul>\n\n\n\n<p>\u3053\u306e\u3088\u3046\u306b\u3001union\u306f\u7279\u5b9a\u306e\u72b6\u6cc1\u4e0b\u3067\u30e1\u30e2\u30ea\u52b9\u7387\u5316\u3068\u30c7\u30fc\u30bf\u89e3\u91c8\u306e\u67d4\u8edf\u6027\u3092\u63d0\u4f9b\u3059\u308b\u5f37\u529b\u306a\u30c4\u30fc\u30eb\u3068\u306a\u308a\u307e\u3059\u3002\u305f\u3060\u3057\u3001\u305d\u306e\u4f7f\u7528\u306b\u306f\u9069\u5207\u306a\u7406\u89e3\u3068\u6ce8\u610f\u304c\u5fc5\u8981\u3067\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-3\">union\u306e\u30e1\u30e2\u30ea\u52b9\u7387\u5316\u30e1\u30ab\u30cb\u30ba\u30e0<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-4\">\u30e1\u30e2\u30ea\u4f7f\u7528\u91cf\u3092\u6700\u5c0f\u9650\u306b\u6291\u3048\u308b\u4ed5\u7d44\u307f<\/h3>\n\n\n\n<p>union\u306e\u30e1\u30e2\u30ea\u52b9\u7387\u5316\u306f\u3001\u8907\u6570\u306e\u30c7\u30fc\u30bf\u578b\u304c\u540c\u4e00\u306e\u30e1\u30e2\u30ea\u7a7a\u9593\u3092\u5171\u6709\u3059\u308b\u3053\u3068\u3067\u5b9f\u73fe\u3055\u308c\u307e\u3059\u3002\u3053\u306e\u4ed5\u7d44\u307f\u306b\u3064\u3044\u3066\u3001\u8a73\u7d30\u306b\u89e3\u8aac\u3057\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\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=\"\">#include &lt;iostream&gt;\n\nunion DataStorage {\n    double large_num;      \/\/ 8\u30d0\u30a4\u30c8\n    int normal_num;        \/\/ 4\u30d0\u30a4\u30c8\n    char small_data;       \/\/ 1\u30d0\u30a4\u30c8\n};\n\nint main() {\n    DataStorage storage;\n\n    \/\/ \u5404\u30e1\u30f3\u30d0\u30fc\u306e\u30b5\u30a4\u30ba\u3092\u78ba\u8a8d\n    std::cout &lt;&lt; \"Size of double: \" &lt;&lt; sizeof(double) &lt;&lt; \" bytes\\n\";\n    std::cout &lt;&lt; \"Size of int: \" &lt;&lt; sizeof(int) &lt;&lt; \" bytes\\n\";\n    std::cout &lt;&lt; \"Size of char: \" &lt;&lt; sizeof(char) &lt;&lt; \" byte\\n\";\n\n    \/\/ union\u5168\u4f53\u306e\u30b5\u30a4\u30ba\u3092\u78ba\u8a8d\n    std::cout &lt;&lt; \"Total size of union: \" &lt;&lt; sizeof(DataStorage) &lt;&lt; \" bytes\\n\";\n\n    return 0;\n}<\/pre>\n\n\n\n<p>\u3053\u306e\u30b3\u30fc\u30c9\u3092\u5b9f\u884c\u3059\u308b\u3068\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u51fa\u529b\u304c\u5f97\u3089\u308c\u307e\u3059\uff1a<\/p>\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=\"\">Size of double: 8 bytes\nSize of int: 4 bytes\nSize of char: 1 byte\nTotal size of union: 8 bytes<\/pre>\n\n\n\n<p>\u30e1\u30e2\u30ea\u52b9\u7387\u5316\u306e\u4e3b\u306a\u30dd\u30a4\u30f3\u30c8\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30b5\u30a4\u30ba\u6c7a\u5b9a\u30e1\u30ab\u30cb\u30ba\u30e0<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>union\u306e\u30b5\u30a4\u30ba\u306f\u6700\u5927\u306e\u30e1\u30f3\u30d0\u30fc\u306e\u30b5\u30a4\u30ba\u306b\u6c7a\u5b9a<\/li>\n\n\n\n<li>\u672a\u4f7f\u7528\u30e1\u30f3\u30d0\u30fc\u7528\u306e\u8ffd\u52a0\u30e1\u30e2\u30ea\u306f\u4e0d\u8981<\/li>\n\n\n\n<li>\u30a2\u30af\u30c6\u30a3\u30d6\u306a\u30e1\u30f3\u30d0\u30fc\u306e\u307f\u304c\u30e1\u30e2\u30ea\u3092\u5360\u6709<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30e1\u30e2\u30ea\u5171\u6709\u306e\u4ed5\u7d44\u307f<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u3059\u3079\u3066\u306e\u30e1\u30f3\u30d0\u30fc\u304c\u540c\u3058\u958b\u59cb\u30a2\u30c9\u30ec\u30b9\u3092\u5171\u6709<\/li>\n\n\n\n<li>\u30e1\u30f3\u30d0\u30fc\u5207\u308a\u66ff\u3048\u6642\u306b\u30e1\u30e2\u30ea\u306e\u518d\u89e3\u91c8\u304c\u767a\u751f<\/li>\n\n\n\n<li>\u7269\u7406\u7684\u306a\u30e1\u30e2\u30ea\u30b3\u30d4\u30fc\u306f\u767a\u751f\u3057\u306a\u3044<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-5\">\u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u3068\u30d1\u30c7\u30a3\u30f3\u30b0\u306e\u6700\u9069\u5316\u65b9\u6cd5<\/h3>\n\n\n\n<p>\u30e1\u30e2\u30ea\u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u3068\u30d1\u30c7\u30a3\u30f3\u30b0\u306f\u3001union\u306e\u30e1\u30e2\u30ea\u52b9\u7387\u5316\u306b\u91cd\u8981\u306a\u5f79\u5272\u3092\u679c\u305f\u3057\u307e\u3059\u3002\u4ee5\u4e0b\u306e\u30b3\u30fc\u30c9\u3067\u5177\u4f53\u7684\u306b\u898b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\uff1a<\/p>\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=\"\">#include &lt;iostream&gt;\n\n\/\/ \u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u6700\u9069\u5316\u524d\u306eunion\nunion UnoptimizedData {\n    char c;           \/\/ 1\u30d0\u30a4\u30c8\n    double d;         \/\/ 8\u30d0\u30a4\u30c8\n    int i;            \/\/ 4\u30d0\u30a4\u30c8\n};\n\n\/\/ \u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u6700\u9069\u5316\u5f8c\u306eunion\nunion OptimizedData {\n    double d;         \/\/ 8\u30d0\u30a4\u30c8\uff08\u6700\u5927\u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u8981\u6c42\uff09\n    int i;            \/\/ 4\u30d0\u30a4\u30c8\n    char c;           \/\/ 1\u30d0\u30a4\u30c8\n} __attribute__((packed));  \/\/ \u30d1\u30c7\u30a3\u30f3\u30b0\u3092\u6700\u5c0f\u5316\n\nint main() {\n    std::cout &lt;&lt; \"Unoptimized union size: \" &lt;&lt; sizeof(UnoptimizedData) &lt;&lt; \" bytes\\n\";\n    std::cout &lt;&lt; \"Optimized union size: \" &lt;&lt; sizeof(OptimizedData) &lt;&lt; \" bytes\\n\";\n\n    return 0;\n}<\/pre>\n\n\n\n<p>\u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u6700\u9069\u5316\u306e\u30c6\u30af\u30cb\u30c3\u30af\uff1a<\/p>\n\n\n<div id=\"id-ab14be09-8209-42c7-8905-ff6e7e471f69\">\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u6700\u9069\u5316\u624b\u6cd5<\/th><th>\u8aac\u660e<\/th><th>\u52b9\u679c<\/th><\/tr><\/thead><tbody><tr><td>\u30e1\u30f3\u30d0\u30fc\u9806\u5e8f\u306e\u6700\u9069\u5316<\/td><td>\u6700\u5927\u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u8981\u6c42\u306e\u30e1\u30f3\u30d0\u30fc\u3092\u5148\u982d\u306b\u914d\u7f6e<\/td><td>\u30d1\u30c7\u30a3\u30f3\u30b0\u306e\u524a\u6e1b<\/td><\/tr><tr><td>\u30d1\u30c3\u30af\u30c9\u5c5e\u6027\u306e\u4f7f\u7528<\/td><td>\u30b3\u30f3\u30d1\u30a4\u30e9\u306e\u30d1\u30c7\u30a3\u30f3\u30b0\u633f\u5165\u3092\u5236\u5fa1<\/td><td>\u30e1\u30e2\u30ea\u4f7f\u7528\u91cf\u306e\u6700\u5c0f\u5316<\/td><\/tr><tr><td>\u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u6307\u5b9a\u5b50\u306e\u6d3b\u7528<\/td><td>\u30e1\u30f3\u30d0\u30fc\u3054\u3068\u306e\u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u8981\u6c42\u3092\u660e\u793a\u7684\u306b\u6307\u5b9a<\/td><td>\u6700\u9069\u306a\u30e1\u30e2\u30ea\u30ec\u30a4\u30a2\u30a6\u30c8\u306e\u5b9f\u73fe<\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n\n\n<p>\u5b9f\u8df5\u7684\u306a\u6700\u9069\u5316\u30c6\u30af\u30cb\u30c3\u30af\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30b5\u30a4\u30ba\u30d9\u30fc\u30b9\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=\"\">union SizeOptimizedUnion {\n    \/\/ \u5927\u304d\u3044\u9806\u306b\u914d\u7f6e\n    double large_data;     \/\/ 8\u30d0\u30a4\u30c8\n    float medium_data;     \/\/ 4\u30d0\u30a4\u30c8\n    int16_t small_data;    \/\/ 2\u30d0\u30a4\u30c8\n    int8_t tiny_data;      \/\/ 1\u30d0\u30a4\u30c8\n} __attribute__((aligned(8)));  \/\/ 8\u30d0\u30a4\u30c8\u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u3092\u5f37\u5236<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u30a2\u30af\u30bb\u30b9\u30d1\u30bf\u30fc\u30f3\u30d9\u30fc\u30b9\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=\"\">union AccessOptimizedUnion {\n    \/\/ \u983b\u7e41\u306b\u30a2\u30af\u30bb\u30b9\u3059\u308b\u30e1\u30f3\u30d0\u30fc\u3092\u5148\u982d\u306b\u914d\u7f6e\n    struct {\n        uint32_t flags;    \/\/ \u3088\u304f\u4f7f\u7528\u3059\u308b\u30d5\u30e9\u30b0\n        uint32_t reserved; \/\/ \u4e88\u7d04\u9818\u57df\n    } control;\n    double data[16];       \/\/ \u3081\u3063\u305f\u306b\u4f7f\u7528\u3057\u306a\u3044\u30c7\u30fc\u30bf\n};<\/pre>\n\n\n\n<p>\u6700\u9069\u5316\u6642\u306e\u6ce8\u610f\u70b9\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30d7\u30e9\u30c3\u30c8\u30d5\u30a9\u30fc\u30e0\u4f9d\u5b58\u6027<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u8981\u6c42\u306f\u74b0\u5883\u306b\u3088\u308a\u7570\u306a\u308b<\/li>\n\n\n\n<li>\u79fb\u690d\u6027\u3092\u8003\u616e\u3057\u305f\u8a2d\u8a08\u304c\u91cd\u8981<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306e\u30c8\u30ec\u30fc\u30c9\u30aa\u30d5<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u904e\u5ea6\u306a\u30d1\u30c3\u30ad\u30f3\u30b0\u306f\u30a2\u30af\u30bb\u30b9\u901f\u5ea6\u4f4e\u4e0b\u306e\u53ef\u80fd\u6027<\/li>\n\n\n\n<li>\u4f7f\u7528\u30d1\u30bf\u30fc\u30f3\u306b\u5fdc\u3058\u305f\u9069\u5207\u306a\u6700\u9069\u5316\u304c\u5fc5\u8981<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30e1\u30f3\u30c6\u30ca\u30f3\u30b9\u6027<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u6700\u9069\u5316\u306e\u610f\u56f3\u3092\u660e\u78ba\u306b\u3059\u308b\u30b3\u30e1\u30f3\u30c8\u306e\u8ffd\u52a0<\/li>\n\n\n\n<li>\u5c06\u6765\u306e\u5909\u66f4\u3092\u8003\u616e\u3057\u305f\u67d4\u8edf\u306a\u8a2d\u8a08<\/li>\n<\/ul>\n\n\n\n<p>\u3053\u306e\u3088\u3046\u306b\u3001union\u306e\u30e1\u30e2\u30ea\u52b9\u7387\u5316\u306f\u3001\u9069\u5207\u306a\u30e1\u30f3\u30d0\u30fc\u914d\u7f6e\u3068\u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u5236\u5fa1\u306b\u3088\u308a\u5b9f\u73fe\u3067\u304d\u307e\u3059\u3002\u305f\u3060\u3057\u3001\u6700\u9069\u5316\u306e\u5ea6\u5408\u3044\u306f\u4f7f\u7528\u72b6\u6cc1\u3084\u30d7\u30e9\u30c3\u30c8\u30d5\u30a9\u30fc\u30e0\u306e\u7279\u6027\u3092\u8003\u616e\u3057\u3066\u6c7a\u5b9a\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-6\">\u5b9f\u8df5\u7684\u306aunion\u306e\u6d3b\u7528\u6cd57\u9078<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-7\">\u30d0\u30a4\u30c8\u914d\u5217\u3068\u6570\u5024\u578b\u306e\u76f8\u4e92\u5909\u63db\u30c6\u30af\u30cb\u30c3\u30af<\/h3>\n\n\n\n<p>\u6570\u5024\u30c7\u30fc\u30bf\u3068\u30d0\u30a4\u30c8\u5217\u306e\u52b9\u7387\u7684\u306a\u76f8\u4e92\u5909\u63db\u306f\u3001\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u3084\u30d5\u30a1\u30a4\u30eb\u51e6\u7406\u3067\u91cd\u8981\u3067\u3059\u3002<\/p>\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=\"\">union ByteConverter {\n    uint32_t value;\n    uint8_t bytes[4];\n\n    \/\/ \u30a8\u30f3\u30c7\u30a3\u30a2\u30f3\u5909\u63db\u7528\u306e\u30d8\u30eb\u30d1\u30fc\u95a2\u6570\n    uint32_t toNetworkOrder() const {\n        return ((bytes[0] &lt;&lt; 24) | (bytes[1] &lt;&lt; 16) |\n                (bytes[2] &lt;&lt; 8)  | bytes[3]);\n    }\n};\n\n\/\/ \u4f7f\u7528\u4f8b\nvoid demonstrateByteConversion() {\n    ByteConverter conv;\n    conv.value = 0x12345678;\n\n    \/\/ \u30d0\u30a4\u30c8\u5358\u4f4d\u3067\u306e\u30a2\u30af\u30bb\u30b9\n    for(int i = 0; i &lt; 4; ++i) {\n        std::cout &lt;&lt; std::hex &lt;&lt; static_cast&lt;int&gt;(conv.bytes[i]) &lt;&lt; \" \";\n    }\n\n    \/\/ \u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u30d0\u30a4\u30c8\u30aa\u30fc\u30c0\u30fc\u306b\u5909\u63db\n    uint32_t network_value = conv.toNetworkOrder();\n}<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-8\">\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u30d7\u30ed\u30c8\u30b3\u30eb\u306e\u30d1\u30b1\u30c3\u30c8\u51e6\u7406\u306e\u52b9\u7387\u5316<\/h3>\n\n\n\n<p>\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u30d1\u30b1\u30c3\u30c8\u306e\u89e3\u6790\u3068\u69cb\u7bc9\u3092\u52b9\u7387\u7684\u306b\u884c\u3046\u305f\u3081\u306eunion\u306e\u6d3b\u7528\u4f8b\u3067\u3059\u3002<\/p>\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=\"\">#pragma pack(push, 1)  \/\/ \u30d1\u30c7\u30a3\u30f3\u30b0\u3092\u7121\u52b9\u5316\nunion IPPacket {\n    struct {\n        uint8_t version_ihl;    \/\/ \u30d0\u30fc\u30b8\u30e7\u30f3\u3068\u30d8\u30c3\u30c0\u9577\n        uint8_t tos;            \/\/ \u30b5\u30fc\u30d3\u30b9\u30bf\u30a4\u30d7\n        uint16_t total_length;  \/\/ \u5168\u4f53\u306e\u9577\u3055\n        uint16_t id;            \/\/ \u8b58\u5225\u5b50\n        uint16_t flags_offset;  \/\/ \u30d5\u30e9\u30b0\u3068\u30d5\u30e9\u30b0\u30e1\u30f3\u30c8\u30aa\u30d5\u30bb\u30c3\u30c8\n        uint8_t ttl;            \/\/ \u751f\u5b58\u6642\u9593\n        uint8_t protocol;       \/\/ \u30d7\u30ed\u30c8\u30b3\u30eb\n        uint16_t checksum;      \/\/ \u30c1\u30a7\u30c3\u30af\u30b5\u30e0\n        uint32_t src_ip;        \/\/ \u9001\u4fe1\u5143IP\n        uint32_t dst_ip;        \/\/ \u5b9b\u5148IP\n    } header;\n    uint8_t raw[20];  \/\/ \u751f\u306e\u30d1\u30b1\u30c3\u30c8\u30c7\u30fc\u30bf\n};\n#pragma pack(pop)\n\n\/\/ \u4f7f\u7528\u4f8b\nvoid processPacket(const uint8_t* packet_data) {\n    IPPacket packet;\n    memcpy(packet.raw, packet_data, sizeof(packet.raw));\n\n    \/\/ \u30d8\u30c3\u30c0\u30fc\u30d5\u30a3\u30fc\u30eb\u30c9\u3078\u306e\u7c21\u5358\u306a\u30a2\u30af\u30bb\u30b9\n    uint8_t version = packet.header.version_ihl &gt;&gt; 4;\n    uint8_t ihl = packet.header.version_ihl &amp; 0x0F;\n}<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-9\">\u30e1\u30e2\u30ea\u30de\u30c3\u30d7\u30c9IO\u306e\u5b9f\u88c5\u65b9\u6cd5<\/h3>\n\n\n\n<p>\u30cf\u30fc\u30c9\u30a6\u30a7\u30a2\u30ec\u30b8\u30b9\u30bf\u3078\u306e\u52b9\u7387\u7684\u306a\u30a2\u30af\u30bb\u30b9\u3092\u5b9f\u73fe\u3059\u308b\u4f8b\u3067\u3059\u3002<\/p>\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=\"\">union HardwareRegister {\n    struct {\n        uint32_t status: 2;     \/\/ \u30b9\u30c6\u30fc\u30bf\u30b9\u30d3\u30c3\u30c8\n        uint32_t command: 4;    \/\/ \u30b3\u30de\u30f3\u30c9\u30d3\u30c3\u30c8\n        uint32_t data: 26;      \/\/ \u30c7\u30fc\u30bf\u30d3\u30c3\u30c8\n    } fields;\n    uint32_t raw_value;         \/\/ \u30ec\u30b8\u30b9\u30bf\u5168\u4f53\u306e\u5024\n\n    void writeCommand(uint8_t cmd) {\n        fields.command = cmd &amp; 0x0F;  \/\/ 4\u30d3\u30c3\u30c8\u306e\u307f\u4f7f\u7528\n    }\n\n    uint32_t readStatus() const {\n        return fields.status;\n    }\n};\n\n\/\/ \u4f7f\u7528\u4f8b\nvolatile HardwareRegister* const CONTROL_REG = \n    reinterpret_cast&lt;HardwareRegister*&gt;(0x40000000);\n\nvoid updateHardware() {\n    CONTROL_REG-&gt;writeCommand(0x5);  \/\/ \u30b3\u30de\u30f3\u30c9\u9001\u4fe1\n    while(CONTROL_REG-&gt;readStatus() != 0) {\n        \/\/ \u51e6\u7406\u5b8c\u4e86\u5f85\u3061\n    }\n}<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-10\">\u578b\u306e\u5171\u7528\u306b\u3088\u308b\u30e1\u30e2\u30ea\u7bc0\u7d04\u30d1\u30bf\u30fc\u30f3<\/h3>\n\n\n\n<p>\u7570\u306a\u308b\u578b\u306e\u30c7\u30fc\u30bf\u3092\u52b9\u7387\u7684\u306b\u683c\u7d0d\u3059\u308b\u4f8b\u3067\u3059\u3002<\/p>\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=\"\">union OptimizedStorage {\n    struct {\n        uint32_t type: 2;       \/\/ \u30c7\u30fc\u30bf\u578b\u8b58\u5225\u5b50\n        uint32_t value: 30;     \/\/ \u5b9f\u969b\u306e\u5024\n    } number;\n    struct {\n        uint32_t type: 2;       \/\/ \u30c7\u30fc\u30bf\u578b\u8b58\u5225\u5b50\n        char str[12];           \/\/ \u6587\u5b57\u5217\u30c7\u30fc\u30bf\n    } text;\n    struct {\n        uint32_t type: 2;       \/\/ \u30c7\u30fc\u30bf\u578b\u8b58\u5225\u5b50\n        float x, y, z;          \/\/ 3D\u5ea7\u6a19\n    } position;\n};\n\n\/\/ \u4f7f\u7528\u4f8b\nclass DataContainer {\n    OptimizedStorage storage;\npublic:\n    void setNumber(uint32_t n) {\n        storage.number.type = 0;\n        storage.number.value = n;\n    }\n    void setText(const char* t) {\n        storage.text.type = 1;\n        strncpy(storage.text.str, t, 11);\n        storage.text.str[11] = '\\0';\n    }\n};<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-11\">\u30b9\u30c6\u30fc\u30c8\u30de\u30b7\u30f3\u306e\u52b9\u7387\u7684\u306a\u5b9f\u88c5<\/h3>\n\n\n\n<p>\u72b6\u614b\u9077\u79fb\u30de\u30b7\u30f3\u3092\u52b9\u7387\u7684\u306b\u5b9f\u88c5\u3059\u308b\u4f8b\u3067\u3059\u3002<\/p>\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=\"\">union StateMachineData {\n    struct IdleState {\n        uint32_t idle_time;\n        bool power_save;\n    } idle;\n\n    struct ProcessingState {\n        uint32_t progress;\n        void* buffer;\n        size_t remaining;\n    } processing;\n\n    struct ErrorState {\n        uint32_t error_code;\n        char message[64];\n    } error;\n};\n\nclass StateMachine {\n    enum State { IDLE, PROCESSING, ERROR };\n    State current_state;\n    StateMachineData data;\n\npublic:\n    void update() {\n        switch(current_state) {\n            case IDLE:\n                if(data.idle.idle_time &gt; 1000) {\n                    data.idle.power_save = true;\n                }\n                break;\n            case PROCESSING:\n                if(data.processing.remaining == 0) {\n                    transitionTo(IDLE);\n                }\n                break;\n            \/\/ ... \u4ed6\u306e\u72b6\u614b\u51e6\u7406\n        }\n    }\n};<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-12\">\u53ef\u5909\u578b\u306e\u5b9f\u88c5\u306b\u3088\u308b\u30a4\u30f3\u30bf\u30d5\u30a7\u30fc\u30b9\u306e\u67d4\u8edf\u5316<\/h3>\n\n\n\n<p>\u7570\u306a\u308b\u578b\u306e\u30c7\u30fc\u30bf\u3092\u7d71\u4e00\u7684\u306b\u6271\u3046\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u3092\u5b9f\u88c5\u3059\u308b\u4f8b\u3067\u3059\u3002<\/p>\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 FlexibleValue {\n    union ValueStorage {\n        bool boolean;\n        int integer;\n        double floating;\n        char string[16];\n\n        ValueStorage() {}  \/\/ \u30c7\u30d5\u30a9\u30eb\u30c8\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\n        ~ValueStorage() {} \/\/ \u30c7\u30b9\u30c8\u30e9\u30af\u30bf\n    };\n\n    enum class Type { BOOL, INT, DOUBLE, STRING } type;\n    ValueStorage storage;\n\npublic:\n    void setBoolean(bool value) {\n        type = Type::BOOL;\n        storage.boolean = value;\n    }\n\n    template&lt;typename T&gt;\n    T getValue() const {\n        switch(type) {\n            case Type::BOOL:\n                return static_cast&lt;T&gt;(storage.boolean);\n            case Type::INT:\n                return static_cast&lt;T&gt;(storage.integer);\n            case Type::DOUBLE:\n                return static_cast&lt;T&gt;(storage.floating);\n            default:\n                throw std::runtime_error(\"Invalid type conversion\");\n        }\n    }\n};<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-13\">\u30d3\u30c3\u30c8\u30d5\u30a3\u30fc\u30eb\u30c9\u3068\u306e\u7d44\u307f\u5408\u308f\u305b\u30c6\u30af\u30cb\u30c3\u30af<\/h3>\n\n\n\n<p>\u30d3\u30c3\u30c8\u30d5\u30a3\u30fc\u30eb\u30c9\u3068union\u3092\u7d44\u307f\u5408\u308f\u305b\u3066\u52b9\u7387\u7684\u306a\u30d3\u30c3\u30c8\u64cd\u4f5c\u3092\u5b9f\u73fe\u3059\u308b\u4f8b\u3067\u3059\u3002<\/p>\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=\"\">union BitFieldManipulator {\n    struct {\n        uint32_t flag1: 1;\n        uint32_t flag2: 1;\n        uint32_t value: 6;\n        uint32_t status: 8;\n        uint32_t reserved: 16;\n    } fields;\n    uint32_t raw_value;\n    uint8_t bytes[4];\n\n    \/\/ \u30d3\u30c3\u30c8\u30d5\u30a3\u30fc\u30eb\u30c9\u306e\u64cd\u4f5c\u30e1\u30bd\u30c3\u30c9\n    void setFlag1(bool state) {\n        fields.flag1 = state ? 1 : 0;\n    }\n\n    void setValue(uint8_t val) {\n        fields.value = val &amp; 0x3F;  \/\/ 6\u30d3\u30c3\u30c8\u307e\u3067\n    }\n\n    \/\/ \u30d0\u30a4\u30c8\u5358\u4f4d\u3067\u306e\u30a2\u30af\u30bb\u30b9\n    uint8_t getStatusByte() const {\n        return bytes[1];  \/\/ status \u30d5\u30a3\u30fc\u30eb\u30c9\u3092\u542b\u3080\u30d0\u30a4\u30c8\n    }\n};\n\n\/\/ \u4f7f\u7528\u4f8b\nvoid demonstrateBitFields() {\n    BitFieldManipulator bfm;\n    bfm.raw_value = 0;  \/\/ \u521d\u671f\u5316\n\n    bfm.setFlag1(true);\n    bfm.setValue(42);\n\n    \/\/ \u500b\u5225\u306e\u30d3\u30c3\u30c8\u30d5\u30a3\u30fc\u30eb\u30c9\u3068\u3057\u3066\u64cd\u4f5c\n    bfm.fields.status = 0xFF;\n\n    \/\/ \u30d0\u30a4\u30c8\u914d\u5217\u3068\u3057\u3066\u30a2\u30af\u30bb\u30b9\n    uint8_t status_byte = bfm.getStatusByte();\n}<\/pre>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u5b9f\u88c5\u4f8b\u306f\u3001union\u306e\u5f37\u529b\u306a\u6a5f\u80fd\u3092\u6d3b\u7528\u3057\u3066\u52b9\u7387\u7684\u306a\u30e1\u30e2\u30ea\u4f7f\u7528\u3068\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306e\u6700\u9069\u5316\u3092\u5b9f\u73fe\u3057\u3066\u3044\u307e\u3059\u3002\u5404\u5b9f\u88c5\u30d1\u30bf\u30fc\u30f3\u306f\u3001\u5b9f\u969b\u306e\u958b\u767a\u30b7\u30fc\u30f3\u3067\u983b\u7e41\u306b\u906d\u9047\u3059\u308b\u8ab2\u984c\u306b\u5bfe\u3059\u308b\u5b9f\u8df5\u7684\u306a\u89e3\u6c7a\u7b56\u3092\u63d0\u4f9b\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-14\">union\u3092\u4f7f\u7528\u3059\u308b\u969b\u306e\u6ce8\u610f\u70b9\u3068\u5bfe\u7b56<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-15\">\u578b\u306e\u5b89\u5168\u6027\u3092\u78ba\u4fdd\u3059\u308b\u305f\u3081\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9<\/h3>\n\n\n\n<p>union\u3092\u4f7f\u7528\u3059\u308b\u969b\u306e\u578b\u306e\u5b89\u5168\u6027\u306f\u3001\u6700\u3082\u91cd\u8981\u306a\u8003\u616e\u4e8b\u9805\u306e\u4e00\u3064\u3067\u3059\u3002\u4ee5\u4e0b\u306b\u3001\u578b\u306e\u5b89\u5168\u6027\u3092\u78ba\u4fdd\u3059\u308b\u305f\u3081\u306e\u5177\u4f53\u7684\u306a\u65b9\u6cd5\u3092\u793a\u3057\u307e\u3059\u3002<\/p>\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=\"\">\/\/ \u5b89\u5168\u3067\u306a\u3044union\u306e\u4f7f\u7528\u4f8b\nunion UnsafeUnion {\n    int number;\n    float decimal;\n    char* text;\n};\n\n\/\/ \u578b\u5b89\u5168\u306aunion\u306e\u5b9f\u88c5\nclass SafeUnion {\nprivate:\n    union DataStorage {\n        int number;\n        float decimal;\n        char* text;\n\n        \/\/ \u30c7\u30d5\u30a9\u30eb\u30c8\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\n        DataStorage() : number(0) {}\n    } data;\n\n    enum class Type { NUMBER, DECIMAL, TEXT } current_type;\n\npublic:\n    SafeUnion() : current_type(Type::NUMBER) {\n        \/\/ \u30c7\u30d5\u30a9\u30eb\u30c8\u3067\u6570\u5024\u578b\u3068\u3057\u3066\u521d\u671f\u5316\n    }\n\n    \/\/ \u30c7\u30b9\u30c8\u30e9\u30af\u30bf\u3067\u30ea\u30bd\u30fc\u30b9\u89e3\u653e\u3092\u9069\u5207\u306b\u51e6\u7406\n    ~SafeUnion() {\n        if (current_type == Type::TEXT) {\n            delete[] data.text;\n        }\n    }\n\n    \/\/ \u578b\u5b89\u5168\u306a\u30bb\u30c3\u30bf\u30fc\n    void setNumber(int value) {\n        cleanup();  \/\/ \u65e2\u5b58\u306e\u30ea\u30bd\u30fc\u30b9\u3092\u30af\u30ea\u30fc\u30f3\u30a2\u30c3\u30d7\n        data.number = value;\n        current_type = Type::NUMBER;\n    }\n\n    \/\/ \u578b\u30c1\u30a7\u30c3\u30af\u4ed8\u304d\u30b2\u30c3\u30bf\u30fc\n    int getNumber() const {\n        if (current_type != Type::NUMBER) {\n            throw std::runtime_error(\"Type mismatch: not a number\");\n        }\n        return data.number;\n    }\n\nprivate:\n    \/\/ \u30ea\u30bd\u30fc\u30b9\u30af\u30ea\u30fc\u30f3\u30a2\u30c3\u30d7\u7528\u306e\u30d8\u30eb\u30d1\u30fc\u30e1\u30bd\u30c3\u30c9\n    void cleanup() {\n        if (current_type == Type::TEXT) {\n            delete[] data.text;\n        }\n    }\n};<\/pre>\n\n\n\n<p>\u578b\u5b89\u5168\u6027\u78ba\u4fdd\u306e\u305f\u3081\u306e\u30c1\u30a7\u30c3\u30af\u30ea\u30b9\u30c8\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u578b\u306e\u8ffd\u8de1<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u73fe\u5728\u306e\u30a2\u30af\u30c6\u30a3\u30d6\u306a\u578b\u3092\u660e\u793a\u7684\u306b\u8ffd\u8de1<\/li>\n\n\n\n<li>\u578b\u306e\u5909\u66f4\u6642\u306b\u9069\u5207\u306a\u30af\u30ea\u30fc\u30f3\u30a2\u30c3\u30d7\u3092\u5b9f\u884c<\/li>\n\n\n\n<li>\u4e0d\u6b63\u306a\u578b\u30a2\u30af\u30bb\u30b9\u3092\u9632\u6b62<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30ea\u30bd\u30fc\u30b9\u7ba1\u7406<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30c7\u30b9\u30c8\u30e9\u30af\u30bf\u3067\u306e\u9069\u5207\u306a\u30ea\u30bd\u30fc\u30b9\u89e3\u653e<\/li>\n\n\n\n<li>\u30e1\u30e2\u30ea\u30ea\u30fc\u30af\u306e\u9632\u6b62<\/li>\n\n\n\n<li>\u4f8b\u5916\u5b89\u5168\u6027\u306e\u78ba\u4fdd<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30a2\u30af\u30bb\u30b9\u5236\u5fa1<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>private\u30e1\u30f3\u30d0\u30fc\u306b\u3088\u308b\u30ab\u30d7\u30bb\u30eb\u5316<\/li>\n\n\n\n<li>\u578b\u30c1\u30a7\u30c3\u30af\u4ed8\u304d\u306e\u30a2\u30af\u30bb\u30b5\u30e1\u30bd\u30c3\u30c9<\/li>\n\n\n\n<li>\u4e0d\u6b63\u306a\u4f7f\u7528\u306e\u9632\u6b62<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-16\">\u672a\u5b9a\u7fa9\u52d5\u4f5c\u3092\u907f\u3051\u308b\u305f\u3081\u306e\u5177\u4f53\u7684\u306a\u65b9\u6cd5<\/h3>\n\n\n\n<p>\u672a\u5b9a\u7fa9\u52d5\u4f5c\uff08UB\uff09\u306f\u3001union\u306e\u4f7f\u7528\u6642\u306b\u7279\u306b\u6ce8\u610f\u304c\u5fc5\u8981\u306a\u554f\u984c\u3067\u3059\u3002\u4ee5\u4e0b\u306b\u3001\u4e3b\u306a\u672a\u5b9a\u7fa9\u52d5\u4f5c\u3068\u305d\u306e\u56de\u907f\u65b9\u6cd5\u3092\u793a\u3057\u307e\u3059\u3002<\/p>\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 UBSafeUnion {\nprivate:\n    union Data {\n        struct {\n            uint32_t type_tag: 8;\n            uint32_t value: 24;\n        } tagged_value;\n        float float_value;\n\n        Data() : tagged_value{0, 0} {}  \/\/ \u660e\u793a\u7684\u306a\u521d\u671f\u5316\n    } data;\n\npublic:\n    \/\/ \u578b\u30bf\u30b0\u306e\u5b9a\u7fa9\n    enum class Tag : uint8_t {\n        INTEGER = 1,\n        FLOAT = 2\n    };\n\n    \/\/ \u5b89\u5168\u306a\u5024\u306e\u8a2d\u5b9a\n    void setInteger(int32_t value) {\n        data.tagged_value.type_tag = static_cast&lt;uint8_t&gt;(Tag::INTEGER);\n        data.tagged_value.value = value &amp; 0x00FFFFFF;\n    }\n\n    void setFloat(float value) {\n        \/\/ \u30e1\u30e2\u30ea\u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u306e\u78ba\u8a8d\n        static_assert(sizeof(float) == 4, \"Float must be 4 bytes\");\n        data.float_value = value;\n        data.tagged_value.type_tag = static_cast&lt;uint8_t&gt;(Tag::FLOAT);\n    }\n\n    \/\/ \u578b\u30c1\u30a7\u30c3\u30af\u4ed8\u304d\u306e\u5024\u306e\u53d6\u5f97\n    bool isInteger() const {\n        return data.tagged_value.type_tag == static_cast&lt;uint8_t&gt;(Tag::INTEGER);\n    }\n\n    bool isFloat() const {\n        return data.tagged_value.type_tag == static_cast&lt;uint8_t&gt;(Tag::FLOAT);\n    }\n\n    \/\/ \u5b89\u5168\u306a\u5024\u306e\u53d6\u5f97\n    std::optional&lt;int32_t&gt; getInteger() const {\n        if (isInteger()) {\n            return data.tagged_value.value;\n        }\n        return std::nullopt;\n    }\n\n    std::optional&lt;float&gt; getFloat() const {\n        if (isFloat()) {\n            return data.float_value;\n        }\n        return std::nullopt;\n    }\n};<\/pre>\n\n\n\n<p>\u672a\u5b9a\u7fa9\u52d5\u4f5c\u3092\u9632\u3050\u305f\u3081\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9\uff1a<\/p>\n\n\n<div id=\"id-f81cf94f-80b2-44a6-af5e-5c5d258ea2ac\">\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u554f\u984c\u70b9<\/th><th>\u5bfe\u7b56<\/th><th>\u5b9f\u88c5\u65b9\u6cd5<\/th><\/tr><\/thead><tbody><tr><td>\u521d\u671f\u5316\u3055\u308c\u3066\u3044\u306a\u3044\u30e1\u30f3\u30d0\u30fc\u3078\u306e\u30a2\u30af\u30bb\u30b9<\/td><td>\u660e\u793a\u7684\u306a\u521d\u671f\u5316<\/td><td>\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u3067\u306e\u521d\u671f\u5316<\/td><\/tr><tr><td>\u4e0d\u6b63\u306a\u578b\u5909\u63db<\/td><td>\u578b\u30bf\u30b0\u306b\u3088\u308b\u8ffd\u8de1<\/td><td>enum class\u3068\u578b\u30c1\u30a7\u30c3\u30af<\/td><\/tr><tr><td>\u30e1\u30e2\u30ea\u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u9055\u53cd<\/td><td>\u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u78ba\u8a8d<\/td><td>static_assert\u306e\u4f7f\u7528<\/td><\/tr><tr><td>\u30ea\u30bd\u30fc\u30b9\u30ea\u30fc\u30af<\/td><td>\u9069\u5207\u306a\u30af\u30ea\u30fc\u30f3\u30a2\u30c3\u30d7<\/td><td>RAII\u539f\u5247\u306e\u9069\u7528<\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n\n\n<p>\u5b9f\u88c5\u6642\u306e\u6ce8\u610f\u70b9\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30e1\u30e2\u30ea\u64cd\u4f5c<\/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=\"\">\/\/ \u5371\u967a\u306a\u5b9f\u88c5\nunion DangerousUnion {\n    int32_t i;\n    float f;\n    void* ptr;\n};\n\n\/\/ \u5b89\u5168\u306a\u5b9f\u88c5\nunion SafeMemoryUnion {\n    int32_t i;\n    float f;\n    void* ptr;\n\n    explicit SafeMemoryUnion(int32_t val) : i(val) {}\n    explicit SafeMemoryUnion(float val) : f(val) {}\n    explicit SafeMemoryUnion(void* val) : ptr(val) {}\n};<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u30d0\u30a4\u30c8\u30a2\u30af\u30bb\u30b9<\/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=\"\">\/\/ \u30e1\u30e2\u30ea\u8868\u73fe\u306b\u4f9d\u5b58\u3057\u306a\u3044\u5b89\u5168\u306a\u30d0\u30a4\u30c8\u30a2\u30af\u30bb\u30b9\ntemplate&lt;typename T&gt;\nclass ByteAccessUnion {\n    union {\n        T value;\n        std::array&lt;uint8_t, sizeof(T)&gt; bytes;\n    } data;\n\npublic:\n    explicit ByteAccessUnion(T val) : data{val} {}\n\n    \/\/ \u30d0\u30a4\u30c8\u5358\u4f4d\u3067\u306e\u5b89\u5168\u306a\u30a2\u30af\u30bb\u30b9\n    uint8_t getByte(size_t index) const {\n        if (index &gt;= sizeof(T)) {\n            throw std::out_of_range(\"Byte index out of range\");\n        }\n        return data.bytes[index];\n    }\n};<\/pre>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u6ce8\u610f\u70b9\u3068\u5bfe\u7b56\u3092\u9069\u5207\u306b\u5b9f\u88c5\u3059\u308b\u3053\u3068\u3067\u3001union\u3092\u5b89\u5168\u304b\u3064\u52b9\u679c\u7684\u306b\u4f7f\u7528\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u578b\u306e\u5b89\u5168\u6027\u3068\u672a\u5b9a\u7fa9\u52d5\u4f5c\u306e\u9632\u6b62\u306f\u3001\u7279\u306b\u91cd\u8981\u306a\u8003\u616e\u4e8b\u9805\u3068\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-17\">C++17\u4ee5\u964d\u306eunion\u306e\u65b0\u6a5f\u80fd\u3068\u6539\u5584\u70b9<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-18\">\u53ef\u5909\u5f15\u6570\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u3068\u306e\u89aa\u548c\u6027\u5411\u4e0a<\/h3>\n\n\n\n<p>C++17\u4ee5\u964d\u3001union\u3068\u53ef\u5909\u5f15\u6570\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u306e\u7d44\u307f\u5408\u308f\u305b\u304c\u5927\u5e45\u306b\u6539\u5584\u3055\u308c\u3001\u3088\u308a\u67d4\u8edf\u306a\u578b\u306e\u53d6\u308a\u6271\u3044\u304c\u53ef\u80fd\u306b\u306a\u308a\u307e\u3057\u305f\u3002<\/p>\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=\"\">#include &lt;type_traits&gt;\n#include &lt;variant&gt;\n\n\/\/ \u53ef\u5909\u5f15\u6570\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u3092\u6d3b\u7528\u3057\u305f\u73fe\u4ee3\u7684\u306aunion\u5b9f\u88c5\ntemplate&lt;typename... Types&gt;\nclass ModernUnion {\n    \/\/ \u5168\u3066\u306e\u578b\u306e\u4e2d\u3067\u6700\u5927\u306e\u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u8981\u6c42\u3092\u6301\u3064\u578b\u3092\u8a08\u7b97\n    static constexpr size_t MaxAlign = \n        std::max({std::alignment_of_v&lt;Types&gt;...});\n\n    \/\/ \u5168\u3066\u306e\u578b\u306e\u4e2d\u3067\u6700\u5927\u306e\u30b5\u30a4\u30ba\u3092\u6301\u3064\u578b\u3092\u8a08\u7b97\n    static constexpr size_t MaxSize = \n        std::max({sizeof(Types)...});\n\n    \/\/ \u30a2\u30e9\u30a4\u30e1\u30f3\u30c8\u8981\u6c42\u3092\u6e80\u305f\u3059\u30b9\u30c8\u30ec\u30fc\u30b8\n    alignas(MaxAlign) std::byte storage[MaxSize];\n    size_t type_index = 0;\n\npublic:\n    template&lt;typename T&gt;\n    void set(T value) {\n        static_assert((std::is_same_v&lt;T, Types&gt; || ...), \n                     \"Invalid type for this union\");\n        new (storage) T(std::move(value));\n        type_index = getTypeIndex&lt;T&gt;();\n    }\n\n    template&lt;typename T&gt;\n    T&amp; get() {\n        if (type_index != getTypeIndex&lt;T&gt;()) {\n            throw std::bad_variant_access();\n        }\n        return *reinterpret_cast&lt;T*&gt;(storage);\n    }\n\nprivate:\n    template&lt;typename T&gt;\n    static constexpr size_t getTypeIndex() {\n        size_t index = 0;\n        bool found = false;\n        ((found = found || std::is_same_v&lt;T, Types&gt;, \n          found ? 0 : ++index), ...);\n        return index;\n    }\n};\n\n\/\/ \u4f7f\u7528\u4f8b\nvoid demonstrateModernUnion() {\n    ModernUnion&lt;int, float, std::string&gt; union_var;\n\n    union_var.set(42);                    \/\/ int\u578b\u3068\u3057\u3066\u8a2d\u5b9a\n    auto int_val = union_var.get&lt;int&gt;();  \/\/ int\u578b\u3068\u3057\u3066\u53d6\u5f97\n\n    union_var.set(3.14f);                 \/\/ float\u578b\u3068\u3057\u3066\u8a2d\u5b9a\n    auto float_val = union_var.get&lt;float&gt;();  \/\/ float\u578b\u3068\u3057\u3066\u53d6\u5f97\n}<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-19\">\u69cb\u9020\u5316\u675f\u7e1b\u306b\u3088\u308b\u30a2\u30af\u30bb\u30b9\u6027\u306e\u5411\u4e0a<\/h3>\n\n\n\n<p>C++17\u3067\u5c0e\u5165\u3055\u308c\u305f\u69cb\u9020\u5316\u675f\u7e1b\u3092\u4f7f\u7528\u3059\u308b\u3053\u3068\u3067\u3001union\u306e\u30e1\u30f3\u30d0\u30fc\u30a2\u30af\u30bb\u30b9\u304c\u3088\u308a\u76f4\u611f\u7684\u306b\u306a\u308a\u307e\u3057\u305f\u3002<\/p>\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=\"\">#include &lt;tuple&gt;\n\n\/\/ \u69cb\u9020\u5316\u675f\u7e1b\u306b\u5bfe\u5fdc\u3057\u305funion\u30e9\u30c3\u30d1\u30fc\nclass StructuredUnion {\n    union DataUnion {\n        struct {\n            int x, y;\n        } point;\n        struct {\n            float width, height;\n        } size;\n\n        DataUnion() : point{0, 0} {}\n    } data;\n\n    bool is_point = true;\n\npublic:\n    \/\/ \u69cb\u9020\u5316\u675f\u7e1b\u7528\u306e\u30bf\u30d7\u30eb\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\n    template&lt;size_t I&gt;\n    decltype(auto) get() &amp; {\n        if constexpr (I == 0) {\n            return is_point ? data.point.x : data.size.width;\n        } else if constexpr (I == 1) {\n            return is_point ? data.point.y : data.size.height;\n        }\n    }\n\n    void setPoint(int x, int y) {\n        data.point = {x, y};\n        is_point = true;\n    }\n\n    void setSize(float w, float h) {\n        data.size = {w, h};\n        is_point = false;\n    }\n};\n\n\/\/ \u69cb\u9020\u5316\u675f\u7e1b\u306e\u30b5\u30dd\u30fc\u30c8\nnamespace std {\n    template&lt;&gt;\n    struct tuple_size&lt;StructuredUnion&gt; : std::integral_constant&lt;size_t, 2&gt; {};\n\n    template&lt;size_t I&gt;\n    struct tuple_element&lt;I, StructuredUnion&gt; {\n        using type = decltype(std::declval&lt;StructuredUnion&gt;().template get&lt;I&gt;());\n    };\n}\n\n\/\/ \u4f7f\u7528\u4f8b\nvoid demonstrateStructuredBinding() {\n    StructuredUnion u;\n    u.setPoint(10, 20);\n\n    \/\/ \u69cb\u9020\u5316\u675f\u7e1b\u3092\u4f7f\u7528\u3057\u305f\u5024\u306e\u53d6\u5f97\n    auto [x, y] = u;\n\n    u.setSize(1.5f, 2.5f);\n    auto [width, height] = u;\n}<\/pre>\n\n\n\n<p>C++17\u4ee5\u964d\u306e\u6539\u5584\u70b9\u306e\u4e3b\u306a\u7279\u5fb4\uff1a<\/p>\n\n\n<div id=\"id-84f75626-a625-4b41-9e72-2a1f768c4621\">\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u6a5f\u80fd<\/th><th>\u6539\u5584\u70b9<\/th><th>\u30e1\u30ea\u30c3\u30c8<\/th><\/tr><\/thead><tbody><tr><td>\u53ef\u5909\u5f15\u6570\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u5bfe\u5fdc<\/td><td>\u578b\u5b89\u5168\u6027\u306e\u5411\u4e0a<\/td><td>\u67d4\u8edf\u306a\u578b\u306e\u53d6\u308a\u6271\u3044<\/td><\/tr><tr><td>\u69cb\u9020\u5316\u675f\u7e1b\u30b5\u30dd\u30fc\u30c8<\/td><td>\u30a2\u30af\u30bb\u30b9\u6027\u306e\u6539\u5584<\/td><td>\u3088\u308a\u76f4\u611f\u7684\u306a\u4f7f\u7528\u65b9\u6cd5<\/td><\/tr><tr><td>\u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u578b\u30c1\u30a7\u30c3\u30af<\/td><td>\u30a8\u30e9\u30fc\u306e\u65e9\u671f\u767a\u898b<\/td><td>\u5b9f\u884c\u6642\u30a8\u30e9\u30fc\u306e\u9632\u6b62<\/td><\/tr><tr><td>\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30e1\u30bf\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0<\/td><td>\u6c4e\u7528\u6027\u306e\u5411\u4e0a<\/td><td>\u518d\u5229\u7528\u53ef\u80fd\u306a\u30b3\u30fc\u30c9<\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n\n\n<p>\u65b0\u6a5f\u80fd\u6d3b\u7528\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u578b\u5b89\u5168\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=\"\">template&lt;typename... Types&gt;\nclass SafeVariantUnion {\n    std::variant&lt;Types...&gt; data;\n\npublic:\n    template&lt;typename T&gt;\n    void set(T value) {\n        data = std::move(value);\n    }\n\n    template&lt;typename T&gt;\n    T&amp; get() {\n        return std::get&lt;T&gt;(data);\n    }\n\n    template&lt;typename T&gt;\n    bool holds() const {\n        return std::holds_alternative&lt;T&gt;(data);\n    }\n};<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u30e1\u30e2\u30ea\u30ec\u30a4\u30a2\u30a6\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=\"\">template&lt;typename... Types&gt;\nclass OptimizedUnion {\n    static constexpr size_t StorageSize = \n        std::max({sizeof(Types)...});\n    static constexpr size_t StorageAlign = \n        std::max({std::alignment_of_v&lt;Types&gt;...});\n\n    alignas(StorageAlign) std::byte storage[StorageSize];\n    std::size_t active_type = std::variant_npos;\n\n    \/\/ \u30e1\u30e2\u30ea\u30ec\u30a4\u30a2\u30a6\u30c8\u306e\u6700\u9069\u5316\u306e\u305f\u3081\u306e\u30d8\u30eb\u30d1\u30fc\u95a2\u6570\n    template&lt;typename T&gt;\n    static constexpr bool IsProperlyAligned() {\n        return (reinterpret_cast&lt;std::uintptr_t&gt;(storage) % \n                std::alignment_of_v&lt;T&gt;) == 0;\n    }\n};<\/pre>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u65b0\u6a5f\u80fd\u3068\u6539\u5584\u70b9\u306b\u3088\u308a\u3001C++17\u4ee5\u964d\u306eunion\u306f\u3088\u308a\u5b89\u5168\u3067\u4f7f\u3044\u3084\u3059\u3044\u3082\u306e\u3068\u306a\u3063\u3066\u3044\u307e\u3059\u3002\u7279\u306b\u3001\u578b\u5b89\u5168\u6027\u306e\u5411\u4e0a\u3068\u69cb\u9020\u5316\u675f\u7e1b\u306e\u30b5\u30dd\u30fc\u30c8\u306f\u3001\u5b9f\u8df5\u7684\u306a\u30b3\u30fc\u30c7\u30a3\u30f3\u30b0\u306b\u304a\u3044\u3066\u5927\u304d\u306a\u4fa1\u5024\u3092\u63d0\u4f9b\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-20\">union\u306e\u5b9f\u8df5\u7684\u306a\u4ee3\u66ff\u624b\u6bb5\u3068\u4f7f\u3044\u5206\u3051<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-21\">std::variant\u3068\u306e\u6bd4\u8f03\u3068\u9069\u5207\u306a\u9078\u629e\u57fa\u6e96<\/h3>\n\n\n\n<p>C++17\u3067\u5c0e\u5165\u3055\u308c\u305f<code>std::variant<\/code>\u306f\u3001\u578b\u5b89\u5168\u306a\u9078\u629e\u80a2\u3068\u3057\u3066union\u306e\u4ee3\u66ff\u3068\u306a\u308b\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002\u4e21\u8005\u306e\u7279\u5fb4\u3092\u6bd4\u8f03\u3057\u3001\u9069\u5207\u306a\u4f7f\u7528\u5834\u9762\u3092\u691c\u8a0e\u3057\u307e\u3059\u3002<\/p>\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=\"\">#include &lt;variant&gt;\n#include &lt;string&gt;\n#include &lt;iostream&gt;\n\n\/\/ \u5f93\u6765\u306eunion\u306b\u3088\u308b\u5b9f\u88c5\nunion TraditionalUnion {\n    int number;\n    float decimal;\n    char string[64];\n\n    TraditionalUnion() : number(0) {}  \/\/ \u30c7\u30d5\u30a9\u30eb\u30c8\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\n};\n\n\/\/ std::variant\u3092\u4f7f\u7528\u3057\u305f\u5b9f\u88c5\nclass ModernVariant {\n    std::variant&lt;int, float, std::string&gt; data;\n\npublic:\n    \/\/ \u578b\u5b89\u5168\u306a\u8a2d\u5b9a\u30e1\u30bd\u30c3\u30c9\n    void setNumber(int n) { data = n; }\n    void setDecimal(float f) { data = f; }\n    void setString(const std::string&amp; s) { data = s; }\n\n    \/\/ \u578b\u30c1\u30a7\u30c3\u30af\u4ed8\u304d\u306e\u53d6\u5f97\u30e1\u30bd\u30c3\u30c9\n    bool isNumber() const { return std::holds_alternative&lt;int&gt;(data); }\n    bool isDecimal() const { return std::holds_alternative&lt;float&gt;(data); }\n    bool isString() const { return std::holds_alternative&lt;string&gt;(data); }\n\n    \/\/ \u5024\u306e\u53d6\u5f97\n    template&lt;typename T&gt;\n    T getValue() const {\n        return std::get&lt;T&gt;(data);\n    }\n};\n\n\/\/ \u4f7f\u7528\u4f8b\u3068\u6bd4\u8f03\nvoid compareImplementations() {\n    \/\/ union\u306e\u4f7f\u7528\n    TraditionalUnion u;\n    u.number = 42;\n    \/\/ \u5371\u967a: \u578b\u306e\u8ffd\u8de1\u304c\u5fc5\u8981\n    std::cout &lt;&lt; u.decimal;  \/\/ \u672a\u5b9a\u7fa9\u52d5\u4f5c\n\n    \/\/ variant\u306e\u4f7f\u7528\n    ModernVariant v;\n    v.setNumber(42);\n    \/\/ \u5b89\u5168: \u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306e\u578b\u30c1\u30a7\u30c3\u30af\n    if (v.isNumber()) {\n        std::cout &lt;&lt; v.getValue&lt;int&gt;();\n    }\n}<\/pre>\n\n\n\n<p>union\u3068std::variant\u306e\u6bd4\u8f03\uff1a<\/p>\n\n\n<div id=\"id-3549df2e-eba0-4668-9f0a-413160987a65\">\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u7279\u5fb4<\/th><th>union<\/th><th>std::variant<\/th><\/tr><\/thead><tbody><tr><td>\u30e1\u30e2\u30ea\u4f7f\u7528\u91cf<\/td><td>\u6700\u5927\u30e1\u30f3\u30d0\u30fc\u306e\u30b5\u30a4\u30ba<\/td><td>\u6700\u5927\u578b\u306e\u30b5\u30a4\u30ba + \u5236\u5fa1\u60c5\u5831<\/td><\/tr><tr><td>\u578b\u5b89\u5168\u6027<\/td><td>\u624b\u52d5\u3067\u7ba1\u7406\u5fc5\u8981<\/td><td>\u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u30c1\u30a7\u30c3\u30af<\/td><\/tr><tr><td>\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9<\/td><td>\u6700\u9069<\/td><td>\u308f\u305a\u304b\u306a\u30aa\u30fc\u30d0\u30fc\u30d8\u30c3\u30c9<\/td><\/tr><tr><td>\u4f7f\u7528\u8907\u96d1\u6027<\/td><td>\u4e2d\u301c\u9ad8<\/td><td>\u4f4e<\/td><\/tr><tr><td>\u30a8\u30e9\u30fc\u51e6\u7406<\/td><td>\u624b\u52d5\u5b9f\u88c5\u5fc5\u8981<\/td><td>\u7d44\u307f\u8fbc\u307f\u6a5f\u80fd<\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n\n\n<p>\u4f7f\u3044\u5206\u3051\u306e\u6307\u91dd\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>union\u3092\u9078\u629e\u3059\u308b\u5834\u5408<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30e1\u30e2\u30ea\u52b9\u7387\u304c\u6700\u91cd\u8981<\/li>\n\n\n\n<li>\u30d3\u30c3\u30c8\u30ec\u30d9\u30eb\u306e\u64cd\u4f5c\u304c\u5fc5\u8981<\/li>\n\n\n\n<li>\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u304c\u91cd\u8981<\/li>\n\n\n\n<li>\u7d44\u307f\u8fbc\u307f\u30b7\u30b9\u30c6\u30e0\u3067\u306e\u4f7f\u7528<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>std::variant\u3092\u9078\u629e\u3059\u308b\u5834\u5408<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u578b\u5b89\u5168\u6027\u304c\u91cd\u8981<\/li>\n\n\n\n<li>\u30a8\u30e9\u30fc\u51e6\u7406\u304c\u5fc5\u8981<\/li>\n\n\n\n<li>\u4fdd\u5b88\u6027\u3092\u91cd\u8996<\/li>\n\n\n\n<li>\u30e2\u30c0\u30f3\u306aC++\u6a5f\u80fd\u3092\u6d3b\u7528\u3057\u305f\u3044<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-22\">\u578b\u5b89\u5168\u306aunion\u306e\u5b9f\u88c5\u30d1\u30bf\u30fc\u30f3<\/h3>\n\n\n\n<p>union\u3092\u4f7f\u7528\u3059\u308b\u5fc5\u8981\u304c\u3042\u308b\u5834\u5408\u3067\u3082\u3001\u578b\u5b89\u5168\u6027\u3092\u78ba\u4fdd\u3059\u308b\u305f\u3081\u306e\u5b9f\u88c5\u30d1\u30bf\u30fc\u30f3\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\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=\"\">\/\/ \u30bf\u30b0\u4ed8\u304dunion\u306e\u5b9f\u88c5\nclass SafeTaggedUnion {\npublic:\n    enum class Type { INT, FLOAT, STRING };\n\nprivate:\n    union Data {\n        int i;\n        float f;\n        char s[64];\n\n        Data() : i(0) {}  \/\/ \u30c7\u30d5\u30a9\u30eb\u30c8\u3067\u6574\u6570\u578b\u3068\u3057\u3066\u521d\u671f\u5316\n    } data;\n\n    Type current_type;\n\n    \/\/ \u578b\u5909\u66f4\u6642\u306e\u5b89\u5168\u306a\u521d\u671f\u5316\n    template&lt;typename T&gt;\n    void initializeAs() {\n        if constexpr (std::is_same_v&lt;T, int&gt;) {\n            data.i = 0;\n            current_type = Type::INT;\n        } else if constexpr (std::is_same_v&lt;T, float&gt;) {\n            data.f = 0.0f;\n            current_type = Type::FLOAT;\n        } else if constexpr (std::is_same_v&lt;T, const char*&gt;) {\n            data.s[0] = '\\0';\n            current_type = Type::STRING;\n        }\n    }\n\npublic:\n    SafeTaggedUnion() : current_type(Type::INT) {\n        data.i = 0;\n    }\n\n    \/\/ \u578b\u5b89\u5168\u306a\u30bb\u30c3\u30bf\u30fc\n    void set(int value) {\n        initializeAs&lt;int&gt;();\n        data.i = value;\n    }\n\n    void set(float value) {\n        initializeAs&lt;float&gt;();\n        data.f = value;\n    }\n\n    void set(const char* value) {\n        initializeAs&lt;const char*&gt;();\n        strncpy(data.s, value, 63);\n        data.s[63] = '\\0';\n    }\n\n    \/\/ \u578b\u5b89\u5168\u306a\u30b2\u30c3\u30bf\u30fc\n    template&lt;typename T&gt;\n    std::optional&lt;T&gt; get() const {\n        if constexpr (std::is_same_v&lt;T, int&gt;) {\n            if (current_type == Type::INT) {\n                return data.i;\n            }\n        } else if constexpr (std::is_same_v&lt;T, float&gt;) {\n            if (current_type == Type::FLOAT) {\n                return data.f;\n            }\n        } else if constexpr (std::is_same_v&lt;T, const char*&gt;) {\n            if (current_type == Type::STRING) {\n                return data.s;\n            }\n        }\n        return std::nullopt;\n    }\n};\n\n\/\/ \u30ab\u30b9\u30bf\u30e0\u30e1\u30e2\u30ea\u30ec\u30a4\u30a2\u30a6\u30c8\u304c\u5fc5\u8981\u306a\u5834\u5408\u306e\u5b9f\u88c5\ntemplate&lt;typename... Types&gt;\nclass CustomLayoutUnion {\n    static constexpr size_t MaxSize = std::max({sizeof(Types)...});\n    static constexpr size_t MaxAlign = std::max({std::alignment_of_v&lt;Types&gt;...});\n\n    alignas(MaxAlign) std::byte storage[MaxSize];\n    std::size_t type_index;\n\n    template&lt;typename T&gt;\n    static constexpr bool IsValidType = (std::is_same_v&lt;T, Types&gt; || ...);\n\npublic:\n    CustomLayoutUnion() : type_index(0) {\n        std::memset(storage, 0, MaxSize);\n    }\n\n    template&lt;typename T&gt;\n    void set(const T&amp; value) {\n        static_assert(IsValidType&lt;T&gt;, \"Invalid type for this union\");\n        std::memcpy(storage, &amp;value, sizeof(T));\n        type_index = getTypeIndex&lt;T&gt;();\n    }\n\n    template&lt;typename T&gt;\n    std::optional&lt;T&gt; get() const {\n        if (type_index == getTypeIndex&lt;T&gt;()) {\n            T value;\n            std::memcpy(&amp;value, storage, sizeof(T));\n            return value;\n        }\n        return std::nullopt;\n    }\n\nprivate:\n    template&lt;typename T&gt;\n    static constexpr size_t getTypeIndex() {\n        size_t index = 0;\n        bool found = false;\n        ((found = found || std::is_same_v&lt;T, Types&gt;, \n          found ? 0 : ++index), ...);\n        return index;\n    }\n};<\/pre>\n\n\n\n<p>\u5b9f\u88c5\u30d1\u30bf\u30fc\u30f3\u9078\u629e\u306e\u6307\u91dd\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u57fa\u672c\u7684\u306a\u578b\u5b89\u5168union<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30b7\u30f3\u30d7\u30eb\u306a\u578b\u306e\u7d44\u307f\u5408\u308f\u305b<\/li>\n\n\n\n<li>\u660e\u78ba\u306a\u578b\u306e\u533a\u5225\u304c\u5fc5\u8981<\/li>\n\n\n\n<li>\u30a8\u30e9\u30fc\u51e6\u7406\u304c\u91cd\u8981<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30ab\u30b9\u30bf\u30e0\u30e1\u30e2\u30ea\u30ec\u30a4\u30a2\u30a6\u30c8union<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u7279\u6b8a\u306a\u30e1\u30e2\u30ea\u8981\u4ef6\u304c\u3042\u308b<\/li>\n\n\n\n<li>\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306e\u6700\u9069\u5316\u304c\u5fc5\u8981<\/li>\n\n\n\n<li>\u8907\u96d1\u306a\u578b\u306e\u7d44\u307f\u5408\u308f\u305b<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u30cf\u30a4\u30d6\u30ea\u30c3\u30c9\u30a2\u30d7\u30ed\u30fc\u30c1<\/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... Types&gt;\nclass HybridUnion {\n    std::variant&lt;Types...&gt; safe_storage;  \/\/ \u578b\u5b89\u5168\u306a\u90e8\u5206\n    union RawUnion {\n        std::byte bytes[std::max({sizeof(Types)...})];\n        \/\/ \u76f4\u63a5\u30e1\u30e2\u30ea\u30a2\u30af\u30bb\u30b9\u304c\u5fc5\u8981\u306a\u64cd\u4f5c\u7528\n        RawUnion() {}\n    } raw_storage;\n\npublic:\n    \/\/ \u578b\u5b89\u5168\u306a\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\n    template&lt;typename T&gt;\n    void setSafe(const T&amp; value) {\n        safe_storage = value;\n        std::memcpy(raw_storage.bytes, &amp;value, sizeof(T));\n    }\n\n    \/\/ \u4f4e\u30ec\u30d9\u30eb\u64cd\u4f5c\u7528\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\n    void* getRawPtr() {\n        return raw_storage.bytes;\n    }\n};<\/pre>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u5b9f\u88c5\u30d1\u30bf\u30fc\u30f3\u3068\u4ee3\u66ff\u624b\u6bb5\u3092\u9069\u5207\u306b\u9078\u629e\u3059\u308b\u3053\u3068\u3067\u3001\u8981\u4ef6\u306b\u5fdc\u3058\u305f\u6700\u9069\u306a\u30bd\u30ea\u30e5\u30fc\u30b7\u30e7\u30f3\u3092\u5b9f\u73fe\u3067\u304d\u307e\u3059\u3002\u91cd\u8981\u306a\u306e\u306f\u3001\u578b\u5b89\u5168\u6027\u3001\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3001\u30e1\u30e2\u30ea\u52b9\u7387\u306e\u30d0\u30e9\u30f3\u30b9\u3092\u8003\u616e\u3059\u308b\u3053\u3068\u3067\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-1954","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\/1954","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=1954"}],"version-history":[{"count":1,"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=\/wp\/v2\/posts\/1954\/revisions"}],"predecessor-version":[{"id":1955,"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=\/wp\/v2\/posts\/1954\/revisions\/1955"}],"wp:attachment":[{"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1954"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1954"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1954"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}