{"id":45738,"date":"2023-01-12T10:29:44","date_gmt":"2023-12-19T00:49:29","guid":{"rendered":"https:\/\/www.silicloud.com\/zh\/blog\/45738-2\/"},"modified":"2024-04-29T09:35:00","modified_gmt":"2024-04-29T01:35:00","slug":"45738-2","status":"publish","type":"post","link":"https:\/\/www.silicloud.com\/zh\/blog\/45738-2\/","title":{"rendered":""},"content":{"rendered":"

\u3053\u306e\u8a18\u4e8b\u306fRust Advent Calendar 2021\u306e7\u65e5\u76ee\u306e\u8a18\u4e8b\u3067\u3059\u3002<\/p>\n

TLDR<\/h1>\n

Rust\u306eunion\u306b\u3064\u3044\u3066\u3001\u81ea\u4f5cRuby\u51e6\u7406\u7cfb\u306e\u5ba3\u4f1d\u3092\u4ea4\u3048\u3064\u3064\u7d39\u4ecb\u3057\u307e\u3059\u3002\u7d50\u8ad6\u3068\u3057\u3066\u306f\u3001union\u306f\u5371\u306a\u3044\u306e\u3067\u3042\u3093\u307e\u308a\u4f7f\u308f\u306a\u3044\u65b9\u304c\u3088\u3044\u3002<\/p>\n

\u81ea\u5df1\u7d39\u4ecb<\/h1>\n

\u3053\u3093\u306b\u3061\u306f\u3001Rust\u3067 ruruby \u3068\u79f0\u3059\u308bRuby\u30a4\u30f3\u30bf\u30d7\u30ea\u30bf\u3092\u4f5c\u3063\u3066\u3044\u308bmonochrome\u3068\u3044\u3044\u307e\u3059\u3002\u8a00\u8a9e\u51e6\u7406\u7cfb\u304c\u597d\u304d\u3067\u3001\u666e\u6bb5\u306f\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u8a00\u8a9e\u51e6\u7406\u7cfb\u304c\u597d\u304d\u306a\u4eba\u306e\u96c6\u307e\u308aSlack\u3042\u305f\u308a\u3067\u30a6\u30ed\u30a6\u30ed\u3057\u3066\u304a\u308a\u307e\u3059\u3002<\/p>\n

ruruby \u306eGitHub\u30ec\u30dd\u30b8\u30c8\u30ea\u306f\u4e0b\u8a18\u3067\u3059\u3002
\nhttps:\/\/github.com\/sisshiki1969\/ruruby<\/p>\n

\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u8a00\u8a9e\u51e6\u7406\u7cfb\u304c\u597d\u304d\u306a\u4eba\u306e\u96c6\u307e\u308aSlack \u306e\u5165\u308a\u53e3\u306f\u4e0b\u8a18\u3002\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u8a00\u8a9e\u51e6\u7406\u7cfb\u304c\u597d\u304d\u306a\u65b9\u306a\u3089\u3069\u306a\u305f\u3067\u3082\u53c2\u52a0\u3067\u304d\u307e\u3059\u3002
\nhttps:\/\/prog-lang-sys-ja-slack.github.io\/wiki\/<\/p>\n

ruruby \u306fRuby\uff08\u3053\u3053\u3067\u306fC\u8a00\u8a9e\u3067\u66f8\u304b\u308c\u305fCRuby =\u300c\u307f\u3093\u306a\u304c\u4f7f\u3063\u3066\u3044\u308bRuby\u300d\u3092\u6307\u3057\u307e\u3059\uff09\u4e26\u307f\u306e\u9ad8\u901f\u6027\u3092\u76ee\u6a19\u3068\u3057\u3066\u958b\u767a\u3057\u3066\u3044\u307e\u3059\u3002\u51e6\u7406\u7cfb\u306e\u7a2e\u5225\u3068\u3057\u3066\u306f\u3001CRuby\u3068\u540c\u69d8\u306bRuby\u30b3\u30fc\u30c9\u3092\u4eee\u60f3\u30de\u30b7\u30f3\u30b3\u30fc\u30c9\u3078\u30b3\u30f3\u30d1\u30a4\u30eb\u3057\u3066\u5b9f\u884c\u3059\u308b\u3001\u4eee\u60f3\u30de\u30b7\u30f3\u30a4\u30f3\u30bf\u30d7\u30ea\u30bf\uff08VM\u30a4\u30f3\u30bf\u30d7\u30ea\u30bf\uff09\u3067\u3059\u3002\u73fe\u6642\u70b9\u3067\u306e\u30d9\u30f3\u30c1\u30de\u30fc\u30af\u306e\u7d50\u679c\u3092\u4e0b\u8a18\u306b\u63b2\u8f09\u3057\u3066\u3044\u307e\u3059\u3002
\nhttps:\/\/github.com\/sisshiki1969\/ruruby\/wiki\/Benchmarks<\/p>\n

\u4eca\u56de\u306f\u30a4\u30f3\u30bf\u30d7\u30ea\u30bf\u4f5c\u6210\u306e\u4e0a\u3067\u5fc5\u8981\u3068\u306a\u3063\u305fRust\u306eunsafe\u306a\u6a5f\u80fd\u306e\u4e00\u3064\u3068\u3057\u3066union\u3092\u7d39\u4ecb\u3057\u3001\u5b9f\u969b\u306b\u3069\u306e\u3088\u3046\u306b\u4f7f\u3063\u3066\u3044\u308b\u304b\u3092\u8aac\u660e\u3057\u307e\u3059\u3002<\/p>\n

union in Rust<\/h1>\n

union\u306fRust 1.19.0\u3067\u5b89\u5b9a\u5316\u3055\u308c\u305f\u6a5f\u80fd\u3067\u3001struct\u3084enum\u306e\u3088\u3046\u306aRust\u7d44\u307f\u8fbc\u307f\u306e\u30c7\u30fc\u30bf\u69cb\u9020\u3067\u3059\u3002
\nRust Blog: What’s in 1.19.0 stable
\nunion\u306eRFC<\/p>\n

union\u306fenum\u306b\u4f3c\u3066\u3044\u307e\u3059\u304c\u3001\u5185\u90e8\u306b\u30d0\u30ea\u30a2\u30f3\u30c8\u306e\u7a2e\u985e\u3092\u793a\u3059\u30bf\u30b0\u3092\u6301\u3061\u307e\u305b\u3093\u3002<\/p>\n

\u5b9a\u7fa9\u306f<\/p>\n

union<\/span> MyUnion<\/span> {<\/span>\r\n    f1<\/span>:<\/span> u32<\/span>,<\/span>\r\n    f2<\/span>:<\/span> f32<\/span>,<\/span>\r\n}<\/span>\r\n<\/code><\/pre>\n
\u3053\u3093\u306a\u5f62\u3092\u3057\u3066\u3044\u307e\u3059\u3002\u5927\u6587\u5b57\u59cb\u307e\u308a\u306e\u30d0\u30ea\u30a2\u30f3\u30c8\u3092\u5217\u6319\u3059\u308benum\u3068\u9055\u3044\u3001struct\u3068\u540c\u69d8\u306e\u6587\u6cd5\u3067\u30591\u3002\u9055\u3046\u306e\u306fC\u8a00\u8a9e\u306eunion\u3068\u540c\u69d8\u3001\u5168\u3066\u306e\u30d5\u30a3\u30fc\u30eb\u30c9\u304c\u540c\u4e00\u306e\u30e1\u30e2\u30ea\u9818\u57df\u306b\u5272\u308a\u5f53\u3066\u3089\u308c\u308b\u3053\u3068\u3067\u3059\u3002\u4e0a\u306e\u4f8b\u3060\u3068f1\u3068f2\u306f\u540c\u3058\u30e1\u30e2\u30ea\u9818\u57df\u3092\u6307\u3057\u307e\u30592\u3002<\/p>\n
let<\/span> u<\/span> =<\/span> MyUnion<\/span> {<\/span> f1<\/span>:<\/span> 1<\/span> };<\/span>\r\nu<\/span>.f1<\/span> =<\/span> 5<\/span>;<\/span>\r\nlet<\/span> value<\/span> =<\/span> unsafe<\/span> {<\/span> u<\/span>.f1<\/span> };<\/span>\r\n<\/code><\/pre>\n
\uff11\u884c\u76ee\u306e\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u30fb\uff12\u884c\u76ee\u306e\u4ee3\u5165\u306fsafe\u3067\u3059\u304c\u3001\u30d5\u30a3\u30fc\u30eb\u30c9\u306e\u8aad\u307f\u51fa\u3057\u306funsafe\u306a\u64cd\u4f5c\u306b\u306a\u308a\u307e\u3059\u3002union\u3067\u306f\u30c7\u30fc\u30bf\u306e\u5185\u90e8\u306b\u30bf\u30b0\u304c\u306a\u3044\u305f\u3081\u3001\u3069\u306e\u30d5\u30a3\u30fc\u30eb\u30c9\u3068\u3057\u3066\u6271\u3046\u306e\u304c\u6b63\u3057\u3044\u306e\u304b\u3068\u3044\u3046\u60c5\u5831\u304c\u30b3\u30f3\u30d1\u30a4\u30e9\u304b\u3089\u898b\u3048\u306a\u3044\u304b\u3089\u3067\u30593\u3002
\n\u4e0a\u8a18\u306e\u4f8b\u3060\u3068u.f2 = 0.0\u3068\u4ee3\u5165\u3057\u305f\u5f8c\u3001\u8aa4\u3063\u3066u.f1\u3067\u8aad\u307f\u51fa\u305d\u3046\u3068\u3059\u308b\u3068\u610f\u56f3\u3057\u306a\u3044\u5024\u306b\u306a\u308a\u307e\u30594\u3002\u6570\u5024\u3067\u3042\u308c\u3070\u300c\u610f\u56f3\u3057\u306a\u3044\u5024\u300d\u3067\u6e08\u307f\u307e\u3059\u304c\u3001Box\u3084Vec\u306a\u3069\u3001\u30dd\u30a4\u30f3\u30bf\u3068\u3057\u3066\u8aad\u307f\u51fa\u3057\u305f\u5834\u5408\u306b\u306f\u5927\u5909\u3088\u308d\u3057\u304f\u306a\u3044\u4e8b\u614b\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n
\u307e\u305f\u3001Rust\u7279\u6709\u306e\u6ce8\u610f\u70b9\u3068\u3057\u3066\u30d5\u30a3\u30fc\u30eb\u30c9\u66f8\u304d\u63db\u3048\u306e\u969b\u306e\u30c7\u30b9\u30c8\u30e9\u30af\u30bf\u51e6\u7406\uff08drop\uff09\u306e\u554f\u984c\u304c\u3042\u308a\u307e\u3059\u3002enum\u3084struct\u3067\u306f\u5024\u3092\u66f8\u304d\u63db\u3048\u308b\u969b\u3001Rust\u30b3\u30f3\u30d1\u30a4\u30e9\u304c\u53e4\u3044\u65b9\u306e\u5024\u3092\u7834\u68c4\uff08drop\uff09\u3059\u308b\u30b3\u30fc\u30c9\u3092\u81ea\u52d5\u7684\u306b\u633f\u5165\u3057\u307e\u3059\u3002union\u306e\u5834\u5408\u306f\u53e4\u3044\u5024\u304c\u3069\u306e\u30d5\u30a3\u30fc\u30eb\u30c9\u306a\u306e\u304b\u3092\u30b3\u30f3\u30d1\u30a4\u30e9\u304c\u77e5\u308b\u3053\u3068\u304c\u3067\u304d\u306a\u3044\u305f\u3081\u3001\u81ea\u52d5\u7684\u306adrop\u304c\u5b89\u5168\u306b\u884c\u3048\u307e\u305b\u3093\u3002\u3053\u306e\u305f\u3081\u3001\u73fe\u72b6\u3067\u306funion\u306e\u30d5\u30a3\u30fc\u30eb\u30c9\u306fCopy\u306a\u5024\u304b\u3001\u305d\u3046\u3067\u306a\u3044\u5834\u5408\u306b\u306fManuallyDrop\u69cb\u9020\u4f53\u3067\u30e9\u30c3\u30d7\u3057\u3066\u3001\u81ea\u52d5\u7684\u306adrop\u3092\u884c\u308f\u306a\u3044\u3053\u3068\u3092\u30b3\u30f3\u30d1\u30a4\u30e9\u306b\u660e\u793a\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n
std::mem::ManuallyDrop
\nTracking issue for RFC 2514, “Union initialization and Drop”<\/p>\n
\u4ee5\u4e0a\u306e\u4e8b\u60c5\u3067union\u5185\u306e\u30c7\u30fc\u30bf\u306e\u30c7\u30b9\u30c8\u30e9\u30af\u30bf\u51e6\u7406\u306f\u30d7\u30ed\u30b0\u30e9\u30de\u306e\u8cac\u4efb\u3068\u306a\u308a\u3001Drop\u30c8\u30ec\u30a4\u30c8\u3092\u81ea\u5206\u3067\u5b9f\u88c5\u3059\u308b\u304b\u3001\u624b\u52d5\u3067free\u3059\u308b\u306a\u3069\u3057\u3066\u9069\u5207\u306b\u51e6\u7406\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n
\u3067\u3001\u4f55\u304c\u5b09\u3057\u3044\u306e\u304b<\/h1>\n
Rust\u306e\u7279\u5fb4\u306f\u5805\u56fa\u306a\u9759\u7684\u578b\u30b7\u30b9\u30c6\u30e0\u3092\u6301\u3061\u3001\u6240\u6709\u6a29\u306e\u6982\u5ff5\u3067\u30e1\u30e2\u30ea\u5b89\u5168\u6027\u3092\u78ba\u4fdd\u3057\u3064\u3064\u3001\u9ad8\u901f\u306b\u52d5\u4f5c\u3059\u308b\u30b3\u30fc\u30c9\u3092\u751f\u6210\u3067\u304d\u308b\u3053\u3068\u3060\u3068\u601d\u3063\u3066\u3044\u307e\u3059\u3002enum\u306f\u4e0a\u8a18\u306e\u7279\u5fb4\u3092\u3059\u3079\u3066\u5099\u3048\u3066\u3044\u308b\u4e00\u65b9\u3001union\u306e\u3088\u3046\u306aunsafe\u3060\u3089\u3051\u306e\u6a5f\u80fd\u306fRust\u306e\u9577\u6240\u3092\u640d\u306a\u3046\u3082\u306e\u306e\u3088\u3046\u306b\u898b\u3048\u307e\u3059\u3002union\u5c0e\u5165\u306e\u52d5\u6a5f\u3068\u3057\u3066\u306f\u3001\u4e0a\u8a18\u306eRFC\u306b\u3088\u308c\u3070\u3001<\/p>\n
    \n
  1. \n
      C\u8a00\u8a9e\u306eunion\u3068\u306e\u76f8\u4e92\u904b\u7528\u6027<\/ol>\n<\/li>\n<\/ol>\n
       <\/p>\n
        enum\u306b\u6bd4\u3079\u3001\u3088\u308a\u30e1\u30e2\u30ea\u52b9\u7387\u306e\u826f\u3044\u30c7\u30fc\u30bf\u69cb\u9020\u3092\u5b9f\u88c5\u3067\u304d\u308b<\/ol>\n
        \u3068\u3044\u3063\u305f\u70b9\u306b\u3042\u308a\u307e\u3059\u3002\u4ee5\u4e0b\u3001ruruby \u3067\u3069\u3046\u4f7f\u3063\u3066\u3044\u308b\u304b\u307f\u3066\u3044\u304d\u307e\u3059\u3002<\/p>\n
        \u4f7f\u7528\u4f8b<\/h1>\n
        Ruby\u306f\u9759\u7684\u578b\u30b7\u30b9\u30c6\u30e0\u3092\u6301\u305f\u306a\u3044\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u6307\u5411\u8a00\u8a9e\u3067\u3059\u3002ruruby \u3067\u306fRuby\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306fRValue\u3068\u3044\u304664\u30d0\u30a4\u30c8\u306e\u69cb\u9020\u4f53\u306b\u683c\u7d0d\u3055\u308c\u3066\u3044\u307e\u30595\u3002RValue\u306f\u591a\u5c90\u306b\u308f\u305f\u308b\u7a2e\u985e\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u8868\u73fe\u3059\u308b\u305f\u3081\u3001\u5168\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u5171\u901a\u306eclass\u30fbvar_table\u306e\u4ed6\u3001\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u7a2e\u985e\uff08\u2252\u30af\u30e9\u30b9\uff09\u56fa\u6709\u306e\u5185\u90e8\u30c7\u30fc\u30bf\u3092\u4fdd\u6301\u3059\u308bkind\u30d5\u30a3\u30fc\u30eb\u30c9\u3092\u6301\u3061\u307e\u3059\u3002<\/p>\n
        \/\/\/ \u30d2\u30fc\u30d7\u30a2\u30ed\u30b1\u30fc\u30c8\u3055\u308c\u305fRuby\u30aa\u30d6\u30b8\u30a7\u30af\u30c8<\/span>\r\npub<\/span> struct<\/span> RValue<\/span> {<\/span>\r\n    \/\/ 8\u30d0\u30a4\u30c8\u3000\u4e0b\u304b\u3089\uff12\u30d0\u30a4\u30c8\u76ee\u306b\u3001kind\u30d5\u30a3\u30fc\u30eb\u30c9\u304c\u3069\u306eObjKind\u304b\u3092\u793a\u3059\u30bf\u30b0<\/span>\r\n    \/\/         \u304c\u683c\u7d0d\u3055\u308c\u308b<\/span>\r\n    flags<\/span>:<\/span> RVFlag<\/span>,<\/span>\r\n    \/\/ 8\u30d0\u30a4\u30c8\u3000\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u30af\u30e9\u30b9\u3000\u4eca\u56de\u306f\u95a2\u4fc2\u306a\u3057<\/span>\r\n    class<\/span>:<\/span> Module<\/span>,<\/span>\r\n    \/\/ 8\u30d0\u30a4\u30c8\u3000\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u5909\u6570\u30c6\u30fc\u30d6\u30eb\u3000\u4eca\u56de\u306f\u95a2\u4fc2\u306a\u3057<\/span>\r\n    var_table<\/span>:<\/span> Option<\/span><<\/span>Box<\/span><<\/span>ValueTable<\/span>>><\/span>,<\/span>\r\n    \/\/ 40\u30d0\u30a4\u30c8\u3000\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u5185\u90e8\u30c7\u30fc\u30bf<\/span>\r\n    pub<\/span> kind<\/span>:<\/span> ObjKind<\/span>,<\/span>\r\n}<\/span>\r\n\r\npub<\/span> union<\/span> RVFlag<\/span> {<\/span>\r\n    \/\/ \u751f\u304d\u3066\u3044\u308b\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u5834\u5408\uff1akind\u30d5\u30a3\u30fc\u30eb\u30c9\u304c\u3069\u306eObjKind\u304b\u3092\u793a\u3059\u30bf\u30b0<\/span>\r\n    flag<\/span>:<\/span> u64<\/span>,<\/span>\r\n    \/\/ \u56de\u53ce\u3055\u308c\u305f\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u5834\u5408\uff1a\u30ac\u30d9\u30fc\u30b8\u30b3\u30ec\u30af\u30bf\u304c\u30ea\u30f3\u30af\u30ea\u30b9\u30c8\u7528\u306b\u4f7f\u7528\u3000<\/span>\r\n    next<\/span>:<\/span> Option<\/span><<\/span>NonNull<\/span><<\/span>RValue<\/span>>><\/span>,<\/span>\r\n}<\/span>\r\n\r\n#[repr(C)]<\/span>\r\npub<\/span> union<\/span> ObjKind<\/span> {<\/span>\r\n    pub<\/span> float<\/span>:<\/span> f64<\/span>,<\/span>\r\n    pub<\/span> module<\/span>:<\/span> ManuallyDrop<\/span><<\/span>ClassInfo<\/span>><\/span>,<\/span>\r\n    pub<\/span> string<\/span>:<\/span> ManuallyDrop<\/span><<\/span>String<\/span>><\/span>,<\/span>\r\n    pub<\/span> array<\/span>:<\/span> ManuallyDrop<\/span><<\/span>ArrayInfo<\/span>><\/span>,<\/span>\r\n    \/\/ \u4ee5\u4e0b\u7565<\/span>\r\n}<\/span>\r\n<\/code><\/pre>\n
        \u4ee5\u4e0b\u3001RValue\u306e\u69cb\u9020\u3092\u307f\u3066\u3044\u304d\u307e\u3059\u3002
        \n\u307e\u305a\u3001\u6700\u521d\u306eflags\u30d5\u30a3\u30fc\u30eb\u30c9\u304cRVFlag\u3068\u3044\u3046\u540d\u524d\u306eunion\u306b\u306a\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n
          \n
        1. \n
            RValue\u304c\u30a4\u30f3\u30bf\u30d7\u30ea\u30bf\u304b\u3089\u5230\u9054\u53ef\u80fd\u306a\u5834\u5408\uff08\u3064\u307e\u308a\u4eca\u5f8c\u3082\u53c2\u7167\u3055\u308c\u308b\u53ef\u80fd\u6027\u304c\u3042\u308b\u5834\u5408\uff09\u306b\u306fRVFlag\u306eflag\u30d5\u30a3\u30fc\u30eb\u30c9\u304c\u4f7f\u7528\u3055\u308c\u3001kind\u30d5\u30a3\u30fc\u30eb\u30c9\u7528\u306e1\u30d0\u30a4\u30c8\u306e\u30bf\u30b0\u3084\u3001\u305d\u306e\u4ed6\u306e\u30d5\u30e9\u30b0\u985e\u304c\u683c\u7d0d\u3055\u308c\u307e\u3059\u3002\u6700\u4e0b\u4f4d\u30d3\u30c3\u30c8\u306f\u5e38\u306b\uff11\u3068\u306a\u308a\u307e\u3059\u3002<\/ol>\n<\/li>\n<\/ol>\n
             <\/p>\n
              \n
            1. \n
                RValue\u304c\u30a4\u30f3\u30bf\u30d7\u30ea\u30bf\u304b\u3089\u305f\u3069\u308c\u306a\u3044\u5834\u5408\uff08\u3064\u307e\u308a\u4eca\u5f8c\u53c2\u7167\u3055\u308c\u308b\u3053\u3068\u304c\u306a\u3044\u5834\u5408\uff09\u306b\u306f\u30ac\u30d9\u30fc\u30b8\u30b3\u30ec\u30af\u30bf\u304c\u56de\u53ce\u3057\u3066\u30c7\u30b9\u30c8\u30e9\u30af\u30bf\u51e6\u7406\u3092\u884c\u3044\u3001RVFlag\u306enext\u30d5\u30a3\u30fc\u30eb\u30c9\u3068\u3057\u3066\u6b21\u306e\u56de\u53ce\u6e08\u307fRValue\u3078\u306e\u30dd\u30a4\u30f3\u30bf\u3092\u66f8\u304d\u8fbc\u307f\u307e\u3059\u3002\u3053\u306e\u5024\u306f\u6700\u4e0b\u4f4d\u30d3\u30c3\u30c8\u304c\u5fc5\u305a0\u306b\u306a\u308a\u307e\u3059\u30026<\/ol>\n<\/li>\n<\/ol>\n
                 <\/p>\n
                  \u6700\u4e0b\u4f4d\u30d3\u30c3\u30c8\u3092\u307f\u308b\u3053\u3068\u3067\u3001\u4e0a\u8a18\u306e1.\u304b2.\u304b\u304c\u5224\u5b9a\u3067\u304d\u307e\u3059\u3002<\/ol>\n
                  \u6b21\u306b\u3001kind\u30d5\u30a3\u30fc\u30eb\u30c9\u3082union\u3067\u3059\u3002\u3053\u306e\u30d5\u30a3\u30fc\u30eb\u30c9\u306e\u8b58\u5225\u306b\u4f7f\u7528\u3055\u308c\u308b\u30bf\u30b0\uff081\u30d0\u30a4\u30c8\uff09\u306f\u4e0b\u8a18\u306e\u3088\u3046\u306b\u5b9a\u7fa9\u3055\u308c\u3001flags.flag\u306b\u683c\u7d0d\u3055\u308c\u307e\u3059\u3002<\/p>\n
                  impl<\/span> ObjKind<\/span> {<\/span>\r\n    pub<\/span> const<\/span> FLOAT<\/span>:<\/span> u8<\/span> =<\/span> 3<\/span>;<\/span>\r\n    pub<\/span> const<\/span> MODULE<\/span>:<\/span> u8<\/span> =<\/span> 5<\/span>;<\/span>\r\n    pub<\/span> const<\/span> CLASS<\/span>:<\/span> u8<\/span> =<\/span> 20<\/span>;<\/span>\r\n    pub<\/span> const<\/span> STRING<\/span>:<\/span> u8<\/span> =<\/span> 6<\/span>;<\/span>\r\n    pub<\/span> const<\/span> ARRAY<\/span>:<\/span> u8<\/span> =<\/span> 7<\/span>;<\/span>\r\n    \/\/ \u4ee5\u4e0b\u7565<\/span>\r\n}<\/span>\r\n<\/code><\/pre>\n
                  \u4f8b\u3048\u3070\u3001RValue\u3092\u30bf\u30b0\u306b\u5fdc\u3058\u3066String\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3068\u3057\u3066\u6271\u3044\u3001\u5185\u90e8\u306eString\u306e\u53c2\u7167\u3092\u53d6\u5f97\u3059\u308b\u95a2\u6570\u306f\u4e0b\u8a18\u306e\u3088\u3046\u306b\u306a\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n
                      \/\/ \u5b89\u5168\u306b\u30a2\u30af\u30bb\u30b9\u3059\u308b\u305f\u3081\u306b\u307e\u305akind()\u95a2\u6570\u3067\u30bf\u30b0\u3092\u53d6\u5f97\u3057\u3066\u5206\u5c90\u3059\u308b<\/span>\r\n    match<\/span> self<\/span>.kind<\/span>()<\/span> {<\/span>\r\n        ObjKind<\/span>::<\/span>STRING<\/span> =><\/span> {<\/span>\r\n            \/\/ \u4e2d\u306e\u30c7\u30fc\u30bf\u3092\u53d6\u308a\u51fa\u3059<\/span>\r\n            let<\/span> s<\/span>:<\/span> &<\/span>String<\/span> =<\/span> unsafe<\/span> {<\/span> &*<\/span>self<\/span>.kind.string<\/span> };<\/span>\r\n            \/\/ \u306a\u3093\u304b\u51e6\u7406\u3059\u308b<\/span>\r\n        }<\/span>\r\n        \/\/ \u4ee5\u4e0b\u7565<\/span>\r\n    }<\/span>\r\n\r\nimpl<\/span> RValue<\/span> {<\/span>\r\n    \/\/ \u30bf\u30b0\u3092\u53d6\u308a\u51fa\u3059\u95a2\u6570<\/span>\r\n    fn<\/span> kind<\/span>(<\/span>&<\/span>self<\/span>)<\/span> -><\/span> u8<\/span> {<\/span>\r\n        let<\/span> flag<\/span> =<\/span> unsafe<\/span> {<\/span> self<\/span>.flags.flag<\/span> };<\/span>\r\n        \/\/ \u3046\u3063\u304b\u308aGC\u7528\u306e\u30dd\u30a4\u30f3\u30bf\u3092\u8aad\u307e\u306a\u3044\u3088\u3046\u306b\u6700\u4e0b\u4f4d\u30d3\u30c3\u30c8\u304c1\u304b\u78ba\u8a8d<\/span>\r\n        assert<\/span>!<\/span>(<\/span>flag<\/span> &<\/span> 0b1<\/span> ==<\/span> 1<\/span>);<\/span>\r\n        (<\/span>flag<\/span> >><\/span> 8<\/span>)<\/span> as<\/span> u8<\/span>\r\n    }<\/span>\r\n\r\n    \/\/ \u30ac\u30fc\u30d9\u30b8\u30b3\u30ec\u30af\u30bf\u304b\u3089\u547c\u3070\u308c\u308b\u30c7\u30b9\u30c8\u30e9\u30af\u30bf<\/span>\r\n    fn<\/span> free<\/span>(<\/span>&<\/span>mut<\/span> self<\/span>)<\/span> {<\/span>\r\n        unsafe<\/span> {<\/span>\r\n            match<\/span> self<\/span>.kind<\/span>()<\/span> {<\/span>\r\n                ObjKind<\/span>::<\/span>MODULE<\/span> =><\/span> ManuallyDrop<\/span>::<\/span>drop<\/span>(<\/span>&<\/span>mut<\/span> self<\/span>.kind.module<\/span>),<\/span>\r\n                ObjKind<\/span>::<\/span>CLASS<\/span> =><\/span> ManuallyDrop<\/span>::<\/span>drop<\/span>(<\/span>&<\/span>mut<\/span> self<\/span>.kind.module<\/span>),<\/span>\r\n                ObjKind<\/span>::<\/span>STRING<\/span> =><\/span> ManuallyDrop<\/span>::<\/span>drop<\/span>(<\/span>&<\/span>mut<\/span> self<\/span>.kind.string<\/span>),<\/span>\r\n                ObjKind<\/span>::<\/span>ARRAY<\/span> =><\/span> ManuallyDrop<\/span>::<\/span>drop<\/span>(<\/span>&<\/span>mut<\/span> self<\/span>.kind.array<\/span>),<\/span>\r\n                \/\/ \u4ee5\u4e0b\u7565<\/span>\r\n                _<\/span> =><\/span> {}<\/span>\r\n            }<\/span>\r\n            self<\/span>.flags.next<\/span> =<\/span> None<\/span>;<\/span>\r\n            self<\/span>.var_table<\/span> =<\/span> None<\/span>;<\/span>\r\n        }<\/span>\r\n    }<\/span>\r\n}<\/span>\r\n<\/code><\/pre>\n
                  \u307e\u3068\u3081<\/h1>\n
                  Rust\u306eunion\u3092\u6982\u8aac\u3057\u3001\u81ea\u4f5c\u51e6\u7406\u7cfb\u3067\u3069\u306e\u3088\u3046\u306b\u4f7f\u3063\u3066\u3044\u308b\u304b\u3092\u4f8b\u3068\u3057\u3066\u6319\u3052\u307e\u3057\u305f\u3002union\u306f\u5371\u967a\u306a\u3046\u3048\u306b\u4f7f\u3046\u306e\u304c\u9762\u5012\u306a\u306e\u3067\u3001\u3088\u307b\u3069\u306e\u3053\u3068\u304c\u306a\u3044\u9650\u308a\u306fenum\u3092\u4f7f\u3044\u307e\u3057\u3087\u3046\u3002<\/p>\n
                  \n
                  Rust\u3067\u306fstruct\u3084enum\u306f\u3044\u308f\u3086\u308b\u4e88\u7d04\u8a9e\uff08Strict keywords\uff09\u3067\u5909\u6570\u540d\u3084\u95a2\u6570\u540d\u306b\u306f\u4f7f\u3048\u306a\u3044\u3002\u304c\u3001union\u306f”Weak” keywords\u3068\u306a\u3063\u3066\u3044\u3066\u3001\u5909\u6570\u540d\u306b\u3082\u95a2\u6570\u540d\u306b\u3082\u4f7f\u3048\u308b\u3002\u53c2\u8003\uff1aThe Rust reference: Keywords\u00a0\u21a9<\/p>\n
                  \u53b3\u5bc6\u306b\u306funion\u306e\u30e1\u30e2\u30ea\u30ec\u30a4\u30a2\u30a6\u30c8\u306f”unspecified”\u306a\u306e\u3067f1\u3068f2\u304c\u540c\u4e00\u306e\u30e1\u30e2\u30ea\u30a2\u30c9\u30ec\u30b9\u306b\u5272\u308a\u5f53\u3066\u3089\u308c\u308b\u4fdd\u8a3c\u306f\u306a\u3044\uff08\u3088\u3046\u306a\u6c17\u304c\u3059\u308b\uff09\u3002\u30ec\u30a4\u30a2\u30a6\u30c8\u3092\u660e\u793a\u3057\u305f\u3044\u5834\u5408\u306f#[repr(C)]\u30a2\u30c8\u30ea\u30d3\u30e5\u30fc\u30c8\u3092\u4f7f\u7528\u3059\u308b\u3002\u00a0\u21a9<\/p>\n
                  \u4f8b\u793a\u3057\u305f\u30b3\u30fc\u30c9\u306f\u6b63\u3057\u304f\u52d5\u4f5c\u3059\u308b\u304c\u3001\u4e00\u822c\u7684\u306b\u306funion\u306e\u30c7\u30fc\u30bf\u304c\u3069\u306e\u30d5\u30a3\u30fc\u30eb\u30c9\u3068\u3057\u3066\u66f8\u304d\u8fbc\u307e\u308c\u305f\u304b\u306f\u9759\u7684\u306b\u78ba\u5b9a\u3067\u304d\u305a\u3001\u8aa4\u3063\u305f\u30d5\u30a3\u30fc\u30eb\u30c9\u3068\u3057\u3066\u8aad\u307f\u8fbc\u3093\u3067\u3057\u307e\u3046\u3068\u5927\u60e8\u4e8b\u306b\u306a\u308b\u3002\u00a0\u21a9<\/p>\n
                  \u610f\u56f3\u7684\u306bf32\u3067\u66f8\u304d\u8fbc\u3093\u3060\u3082\u306e\u3092u32\u3067\u8aad\u307f\u51fa\u3059\u3001\u3068\u3044\u3046\u5834\u5408\u3082\u3042\u308b\u3002\u00a0\u21a9<\/p>\n
                  RValue\u3068\u3044\u3046\u69cb\u9020\u4f53\u540d\u306fCRuby\u306b\u5408\u308f\u305b\u3066\u540d\u4ed8\u3051\u305f\u3002\u3061\u306a\u307f\u306bCRuby\u306eRValue\u306f\uff0864\u30d3\u30c3\u30c8\u30a2\u30fc\u30ad\u30c6\u30af\u30c1\u30e3\u306e\u5834\u5408\uff0940\u30d0\u30a4\u30c8\u3002\u306a\u304aRValue\u306f\u5e38\u306b\u30d2\u30fc\u30d7\u4e0a\u306b\u78ba\u4fdd\u3055\u308c\u308b\u304c\u3001Vec\u3084Box\u3068\u306f\u7570\u306a\u308aRust\u306e\u30a2\u30ed\u30b1\u30fc\u30bf\u3067\u306f\u306a\u304f\u3001ruruby \u672c\u4f53\u306b\u3042\u308b\u72ec\u81ea\u5b9f\u88c5\u30a2\u30ed\u30b1\u30fc\u30bf\u306b\u3088\u308a\u751f\u6210\u3055\u308c\u308b\u3002\u4e0d\u8981\u3068\u306a\u3063\u305fRValue\u306e\u30c7\u30b9\u30c8\u30e9\u30af\u30bf\u51e6\u7406\u306f\u72ec\u81ea\u5b9f\u88c5\u306e\u30ac\u30d9\u30fc\u30b8\u30b3\u30ec\u30af\u30bf\u304c\u884c\u3046\u3002\u00a0\u21a9<\/p>\n
                  Option<NonNull>\u3067\u306fNonNull>\u304cnull\u306b\u306a\u3089\u306a\u3044\u3053\u3068\u304c\u4fdd\u8a3c\u3055\u308c\u3066\u3044\u308b\u306e\u3067\u3001null\u304cOption::None\u306b\u5272\u308a\u5f53\u3066\u3089\u308c\u3001Option<NonNull>\u306f*mut RValue\u3068\u540c\u3058\u30e1\u30e2\u30ea\u30b5\u30a4\u30ba\u306b\u306a\u308b\u3002\u305d\u3057\u3066RValue\u306e\u5148\u982d\u30a2\u30c9\u30ec\u30b9\u306f\u5e38\u306b8\u30d0\u30a4\u30c8\u30a2\u30e9\u30a4\u30f3\u3055\u308c\u3066\u3044\u308b\u306e\u3067\u3001\u6700\u4e0b\u4f4d3\u30d3\u30c3\u30c8\u306f\u5e38\u306b0\u306b\u306a\u308b\u306f\u305a\u2026\u2026\u3000\u3057\u304b\u3057\u3088\u304f\u8003\u3048\u308b\u3068null\u306e\u30d3\u30c3\u30c8\u8868\u73fe\u306e\u6700\u4e0b\u4f4d\u30d3\u30c3\u30c8\u304c0\u3067\u3042\u308b\u4fdd\u8a3c\u304c\u4ed5\u69d8\u4e0a\u306f\u306a\u3044\u6c17\u304c\u3059\u308b\u2026\u3000\u8a73\u3057\u3044\u4eba\u8ab0\u304b\u6559\u3048\u3066\u304f\u3060\u3055\u3044\u3002\u00a0\u21a9<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"
                  \u3053\u306e\u8a18\u4e8b\u306fRust Advent Calendar 2021\u306e7\u65e5\u76ee\u306e\u8a18\u4e8b\u3067\u3059\u3002 TLDR Rust\u306eunio […]<\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-45738","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"yoast_head":"\n- Blog - Silicon Cloud<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.silicloud.com\/zh\/blog\/45738-2\/\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:description\" content=\"\u3053\u306e\u8a18\u4e8b\u306fRust Advent Calendar 2021\u306e7\u65e5\u76ee\u306e\u8a18\u4e8b\u3067\u3059\u3002 TLDR Rust\u306eunio […]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.silicloud.com\/zh\/blog\/45738-2\/\" \/>\n<meta property=\"og:site_name\" content=\"Blog - Silicon Cloud\" \/>\n<meta property=\"article:published_time\" content=\"2023-12-19T00:49:29+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2024-04-29T01:35:00+00:00\" \/>\n<meta name=\"author\" content=\"\u6587, \u7fd4\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u4f5c\u8005\" \/>\n\t<meta name=\"twitter:data1\" content=\"\u6587, \u7fd4\" \/>\n\t<meta name=\"twitter:label2\" content=\"\u9884\u8ba1\u9605\u8bfb\u65f6\u95f4\" \/>\n\t<meta name=\"twitter:data2\" content=\"2 \u5206\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/45738-2\/\",\"url\":\"https:\/\/www.silicloud.com\/zh\/blog\/45738-2\/\",\"name\":\"- Blog - Silicon Cloud\",\"isPartOf\":{\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/#website\"},\"datePublished\":\"2023-12-19T00:49:29+00:00\",\"dateModified\":\"2024-04-29T01:35:00+00:00\",\"author\":{\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/#\/schema\/person\/64d5cc7727fffbff2f9a2a8da1de3e5c\"},\"inLanguage\":\"zh-Hans\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.silicloud.com\/zh\/blog\/45738-2\/\"]}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/#website\",\"url\":\"https:\/\/www.silicloud.com\/zh\/blog\/\",\"name\":\"Blog - Silicon Cloud\",\"description\":\"\",\"inLanguage\":\"zh-Hans\"},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/#\/schema\/person\/64d5cc7727fffbff2f9a2a8da1de3e5c\",\"name\":\"\u6587, \u7fd4\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"zh-Hans\",\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/920c3d673e0bccacc98e5e6b7149bb3c22edd8d39cb753e5d7d7e471498118a1?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/920c3d673e0bccacc98e5e6b7149bb3c22edd8d39cb753e5d7d7e471498118a1?s=96&d=mm&r=g\",\"caption\":\"\u6587, \u7fd4\"},\"url\":\"https:\/\/www.silicloud.com\/zh\/blog\/author\/wenxiang\/\"},{\"@type\":\"ImageObject\",\"inLanguage\":\"zh-Hans\",\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/45738-2\/#local-main-organization-logo\",\"url\":\"\",\"contentUrl\":\"\",\"caption\":\"Blog - Silicon Cloud\"}]}<\/script>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"- Blog - Silicon Cloud","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.silicloud.com\/zh\/blog\/45738-2\/","og_locale":"zh_CN","og_type":"article","og_description":"\u3053\u306e\u8a18\u4e8b\u306fRust Advent Calendar 2021\u306e7\u65e5\u76ee\u306e\u8a18\u4e8b\u3067\u3059\u3002 TLDR Rust\u306eunio […]","og_url":"https:\/\/www.silicloud.com\/zh\/blog\/45738-2\/","og_site_name":"Blog - Silicon Cloud","article_published_time":"2023-12-19T00:49:29+00:00","article_modified_time":"2024-04-29T01:35:00+00:00","author":"\u6587, \u7fd4","twitter_card":"summary_large_image","twitter_misc":{"\u4f5c\u8005":"\u6587, \u7fd4","\u9884\u8ba1\u9605\u8bfb\u65f6\u95f4":"2 \u5206"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/www.silicloud.com\/zh\/blog\/45738-2\/","url":"https:\/\/www.silicloud.com\/zh\/blog\/45738-2\/","name":"- Blog - Silicon Cloud","isPartOf":{"@id":"https:\/\/www.silicloud.com\/zh\/blog\/#website"},"datePublished":"2023-12-19T00:49:29+00:00","dateModified":"2024-04-29T01:35:00+00:00","author":{"@id":"https:\/\/www.silicloud.com\/zh\/blog\/#\/schema\/person\/64d5cc7727fffbff2f9a2a8da1de3e5c"},"inLanguage":"zh-Hans","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.silicloud.com\/zh\/blog\/45738-2\/"]}]},{"@type":"WebSite","@id":"https:\/\/www.silicloud.com\/zh\/blog\/#website","url":"https:\/\/www.silicloud.com\/zh\/blog\/","name":"Blog - Silicon Cloud","description":"","inLanguage":"zh-Hans"},{"@type":"Person","@id":"https:\/\/www.silicloud.com\/zh\/blog\/#\/schema\/person\/64d5cc7727fffbff2f9a2a8da1de3e5c","name":"\u6587, \u7fd4","image":{"@type":"ImageObject","inLanguage":"zh-Hans","@id":"https:\/\/www.silicloud.com\/zh\/blog\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/920c3d673e0bccacc98e5e6b7149bb3c22edd8d39cb753e5d7d7e471498118a1?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/920c3d673e0bccacc98e5e6b7149bb3c22edd8d39cb753e5d7d7e471498118a1?s=96&d=mm&r=g","caption":"\u6587, \u7fd4"},"url":"https:\/\/www.silicloud.com\/zh\/blog\/author\/wenxiang\/"},{"@type":"ImageObject","inLanguage":"zh-Hans","@id":"https:\/\/www.silicloud.com\/zh\/blog\/45738-2\/#local-main-organization-logo","url":"","contentUrl":"","caption":"Blog - Silicon Cloud"}]}},"_links":{"self":[{"href":"https:\/\/www.silicloud.com\/zh\/blog\/wp-json\/wp\/v2\/posts\/45738","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.silicloud.com\/zh\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.silicloud.com\/zh\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.silicloud.com\/zh\/blog\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/www.silicloud.com\/zh\/blog\/wp-json\/wp\/v2\/comments?post=45738"}],"version-history":[{"count":2,"href":"https:\/\/www.silicloud.com\/zh\/blog\/wp-json\/wp\/v2\/posts\/45738\/revisions"}],"predecessor-version":[{"id":84474,"href":"https:\/\/www.silicloud.com\/zh\/blog\/wp-json\/wp\/v2\/posts\/45738\/revisions\/84474"}],"wp:attachment":[{"href":"https:\/\/www.silicloud.com\/zh\/blog\/wp-json\/wp\/v2\/media?parent=45738"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.silicloud.com\/zh\/blog\/wp-json\/wp\/v2\/categories?post=45738"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.silicloud.com\/zh\/blog\/wp-json\/wp\/v2\/tags?post=45738"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}