{"id":4906,"date":"2018-01-28T21:25:46","date_gmt":"2018-01-28T12:25:46","guid":{"rendered":"https:\/\/theolizer.com\/wordpress\/?p=4906"},"modified":"2018-03-04T03:32:00","modified_gmt":"2018-03-03T18:32:00","slug":"cpp-school2-16","status":"publish","type":"post","link":"https:\/\/theolizer.com\/cpp-school2\/cpp-school2-16\/","title":{"rendered":"\u7b2c16\u56de \u7d9a\u30fb\u53ef\u5909\u9577\u5f15\u6570\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8"},"content":{"rendered":"

\u3053\u3093\u306b\u3061\u306f\u3002\u7530\u539f\u3067\u3059\u3002<\/p>\n

\u4eca\u56de\u306f\u30d1\u30e9\u30e1\u30fc\u30bf\u30fb\u30d1\u30c3\u30af\u306e\u5c55\u958b\u65b9\u6cd5\u306b\u3064\u3044\u3066\u3082\u3046\u5c11\u3057\u89e3\u8aac\u3057\u307e\u3059\u3002\uff11\u3064\u306f\u30d1\u30e9\u30e1\u30fc\u30bf\u30fb\u30d1\u30c3\u30af\u3092\u52a0\u5de5\u3057\u3066\u5c55\u958b\u3067\u304d\u308b\u304a\u8a71\u3001\u3082\u3046\u4e00\u3064\u306f\u518d\u5e30\u3092\u4f7f\u308f\u306a\u3044\u3067\u95a2\u6570\u30d1\u30e9\u30e1\u30fc\u30bf\u30fb\u30d1\u30c3\u30af\u3092\u5c55\u958b\u3059\u308b\u65b9\u6cd5\u3067\u3059\u3002\u5f8c\u8005\u3092\u4f7f\u3048\u308b\u30b1\u30fc\u30b9\u3067\u306f\u4ed5\u7d44\u307f\u3092\u628a\u63e1\u3059\u308c\u3070\u518d\u5e30\u3088\u308a\u306f\u30e1\u30f3\u30c6\u30ca\u30f3\u30b9\u3057\u3084\u3059\u3044\u3088\u3046\u306b\u611f\u3058\u307e\u3059\u3002\uff08\u518d\u5e30\u306f\u3061\u3087\u3063\u3068\u96e3\u3057\u3044\u3067\u3059\u3057\u3002\uff09<\/p>\n

\uff11\uff0e\u30d1\u30e9\u30e1\u30fc\u30bf\u30fb\u30d1\u30c3\u30af\u306e\u52a0\u5de5\u306b\u3064\u3044\u3066<\/h3>\n

\u307e\u305a\u306f\u3001\u524d\u3005\u56de\u306e2-1.\u30d1\u30e9\u30e1\u30fc\u30bf\u30fb\u30d1\u30c3\u30af<\/a>\u3067\u8aac\u660e\u3057\u305f...<\/code>\u306e\u4ed8\u3051\u65b9\u306e\u30eb\u30fc\u30eb<\/a>\u306e2.\u30683.\u306e\u88dc\u8db3\u3067\u3059\u3002<\/p>\n

\u30b5\u30f3\u30d7\u30eb\u30fb\u30bd\u30fc\u30b9\u3082\u7b2c14\u56de\u306e\u3082\u306e\u3092\u4f7f\u3044\u307e\u3059\u304c\u3001\u89e3\u8aac\u3057\u3084\u3059\u3044\u3088\u3046\u5c11\u3057\u4fee\u6b63\u3057\u3066\u3044\u307e\u3059\u3002
\n\u2460\u6539\u884c\u306e\u305f\u3081printLogImpl()\u306bstd::cout << \"\\n\";<\/code>\u3092\u8ffd\u52a0\u3057\u307e\u3057\u305f\u3002
\n\u2461\u30d1\u30e9\u30e1\u30fc\u30bf\u540d\u3092\u3061\u3083\u3093\u3068\u4ed8\u3051\u307e\u3057\u305f\u3002
\n\u2462\u6642\u523b\u3092\u524a\u9664\u3057\u307e\u3057\u305f<\/p>\n

\r\n#include <iostream>\r\n \r\nvoid printLogImpl()\r\n{\r\n    std::cout << "\\n";\r\n}\r\n \r\ntemplate<typename tFirst, typename... tRest>\r\nvoid printLogImpl(tFirst first, tRest... rest)\r\n{\r\n    std::cout << first;\r\n    if (sizeof...(rest)) std::cout << ", ";\r\n    printLogImpl(rest...);\r\n}\r\n \r\ntemplate<typename... tTypes>\r\nvoid printLog(tTypes... iParams)\r\n{\r\n    printLogImpl(iParams...);\r\n}\r\n  \r\nint main()\r\n{\r\n    printLog(1, 1.2, "three");\r\n}\r\n<\/pre>\n
\r\n1, 1.2, three\r\n<\/pre>\n
1-1.\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30fb\u30d1\u30e9\u30e1\u30fc\u30bf\u30fb\u30d1\u30c3\u30af\u306e\u52a0\u5de5<\/span><\/h3>\n
\u30eb\u30fc\u30eb\u306f\u7c21\u5358\u3067\u3059\u3002\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30fb\u30d1\u30e9\u30e1\u30fc\u30bf\u30fb\u30d1\u30c3\u30af\u540d\u306b\u52a0\u5de5\u3092\u65bd\u3057\u3066\u3001\u5f8c\u308d\u306b...<\/code>\u3092\u4ed8\u3051\u308b\u3060\u3051\u3067\u3059\u3002<\/p>\n
\u5b9a\u756a\u306e\u52a0\u5de5\u3068\u3057\u3066\u306f\u3001const&\u3092\u8ffd\u52a0\u3059\u308b\u3082\u306e\u3067\u3059\u3002\u30d1\u30e9\u30e1\u30fc\u30bf\u3092const\u53c2\u7167\u3067\u53d7\u3051\u53d6\u308c\u3070\u3001\u4e00\u6642\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3001\u5909\u6570\u306e\u4e21\u65b9\u3092\u30b3\u30d4\u30fc\u305b\u305a\u306b\u53d7\u3051\u53d6\u308c\u307e\u3059\u3002
\n\u7b2c14\u56de\u306e\u30b5\u30f3\u30d7\u30eb\u306f\u305d\u308c\u3092\u8003\u616e\u3057\u3066\u3044\u307e\u305b\u3093\u306e\u3067\u3001\u5b9f\u306f\u30d1\u30e9\u30e1\u30fc\u30bf\u3092\u30b3\u30d4\u30fc\u3057\u3066\u53d7\u3051\u53d6\u3063\u3066\u3044\u307e\u3059\u3002
\nint\u578b\u7b49\u306e\u5834\u5408\u306f\u30b3\u30d4\u30fc\u3057\u305f\u65b9\u304c\u52b9\u7387\u304c\u826f\u3044\u306e\u3067\u554f\u984c\u306a\u3044\u3067\u3059\u304c\u3001\u30af\u30e9\u30b9\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3067\u30b5\u30a4\u30ba\u304c\u5927\u304d\u3044\u3088\u3046\u306a\u5834\u5408\u306f\u30b3\u30d4\u30fc\u306f\u9802\u3051\u307e\u305b\u3093\u3002\u3053\u306e\u3088\u3046\u306a\u3068\u304d\u306e\u305f\u3081\u306bconst\u53c2\u7167\u3092\u4f7f\u3044\u307e\u3059\u3002<\/p>\n
\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30fb\u30d1\u30e9\u30e1\u30fc\u30bf\u30fb\u30d1\u30c3\u30af\u540d\u306e\u5f8c\u308d\u306b const& \u3092\u8ffd\u52a0\u3057\u3001\u305d\u306e\u5f8c\u308d\u306b...<\/code>\u3092\u4ed8\u3051\u3066\u3044\u307e\u3059\u3002<\/p>\n
\r\n#include <iostream>\r\n \r\nvoid printLogImpl()\r\n{\r\n    std::cout << "\\n";\r\n}\r\n \r\ntemplate<typename tFirst, typename... tRest>\r\nvoid printLogImpl(tFirst const& first, tRest const&... rest)\r\n{\r\n    std::cout << first;\r\n    if (sizeof...(rest)) std::cout << ", ";\r\n    printLogImpl(rest...);\r\n}\r\n \r\ntemplate<typename... tTypes>\r\nvoid printLog(tTypes const&... iParams)\r\n{\r\n    printLogImpl(iParams...);\r\n}\r\n  \r\nint main()\r\n{\r\n    printLog(1, 1.2, "three");\r\n}\r\n<\/pre>\n
\u7d50\u679c\u306f\u540c\u3058\u306a\u306e\u3067\u898b\u305f\u76ee\u3067\u306f\u4f55\u304c\u5909\u308f\u3063\u305f\u304b\u5206\u304b\u308a\u307e\u305b\u3093\u306d\u3002
\n\u305d\u3053\u3067\u3001\u3044\u3064\u3082\u306eTYPENAME\u30de\u30af\u30ed\u3067\u578b\u3092\u8868\u793a\u3057\u3066\u307f\u307e\u3059\u3002\u305d\u306e\u969b\u3001\u7b2c11\u56de\u3067\u8aac\u660e\u3057\u305f<\/a>\u3088\u3046\u306b\u5358\u306bTYPENAME\u30de\u30af\u30ed\u306b\u6e21\u3059\u3068typeid()\u306e\u52b9\u679c\u306e\u305f\u3081\u3001const\u3084&\u304c\u6d88\u3048\u3066\u3057\u307e\u3044\u307e\u3059\u306e\u3067\u3001\u30c0\u30df\u30fc\u306e\u30af\u30e9\u30b9\u30fb\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\uff08Type<tType><\/code>\uff09\u3092\u4ecb\u3057\u307e\u3059\u3002<\/p>\n
\r\n#include <iostream>\r\n#include "typename.h"\r\n\r\ntemplate<typename tType>\r\nstruct Type { };\r\n\r\nvoid printLogImpl()\r\n{\r\n    std::cout << "\\n";\r\n}\r\n \r\ntemplate<typename tFirst, typename... tRest>\r\nvoid printLogImpl(tFirst const& first, tRest const&... rest)\r\n{\r\n    std::cout << first << "[" << TYPENAME(Type<decltype(first)>) << "]";\r\n    if (sizeof...(rest)) std::cout << ", ";\r\n    printLogImpl(rest...);\r\n}\r\n \r\ntemplate<typename... tTypes>\r\nvoid printLog(tTypes const&... iParams)\r\n{\r\n    printLogImpl(iParams...);\r\n}\r\n  \r\nint main()\r\n{\r\n    printLog(1, 1.2, "three");\r\n}\r\n<\/pre>\n
\r\n1[Type<int const&>], 1.2[Type<double const&>], three[Type<char const (&) [6]>]\r\n<\/pre>\n
\u56e0\u307f\u306bconst&\u3092\u8ffd\u52a0\u3057\u306a\u304b\u3063\u305f\u5834\u5408\u306e\u5b9f\u884c\u7d50\u679c\u306f\u6b21\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002const\u53c2\u7167\u306b\u306a\u3063\u3066\u3044\u307e\u305b\u3093\u306e\u3067\u30b3\u30d4\u30fc\u304c\u767a\u751f\u3057\u3066\u3044\u307e\u3059\u3002\uff08\u3068\u306f\u3044\u3048\u3001int\u578b\u3084\u30dd\u30a4\u30f3\u30bf\u578b\u306e\u30b3\u30d4\u30fc\u306f\u554f\u984c\u306a\u3044\u3067\u3059\u3002\u5927\u304d\u306a\u30af\u30e9\u30b9\u306a\u3069\u3092\u6e21\u3057\u305f\u6642\u306b\u30b3\u30d4\u30fc\u30b3\u30b9\u30c8\u304c\u6c17\u306b\u306a\u308a\u307e\u3059\u3002\uff09<\/p>\n
\r\n1[Type<int>], 1.2[Type<double>], three[Type<char const*>]\r\n<\/pre>\n
\n\u524d\u8005\u3067\u3001”three”\u3092const&\u3067\u53d7\u3051\u53d6\u308b\u3068\u578b\u304cchar const (&) [6]\u306b\u306a\u3063\u3066\u3044\u308b\u3053\u3068\u306b\u3061\u3087\u3063\u3068\u9a5a\u304f\u304b\u3082\u77e5\u308c\u307e\u305b\u3093\u3002
\n\u307e\u305a\u3001”three”\u306fchar\u578b\u306e\u914d\u5217\u3067\u3059\u3002\u6587\u5b57\u6570\u304c5\u6587\u5b57\u3067NULL\u7d42\u7aef\u306a\u306e\u30676\u6587\u5b57\u306e\u914d\u5217\u3068\u306a\u308a\u307e\u3059\u3002\u305d\u3057\u3066\u3001\u7b2c13\u56de\u3067\u89e3\u8aac\u3057\u305f\u3088\u3046\u306b\u914d\u5217\u306e\u53c2\u7167\u306f \u578b(&)[\u8981\u7d20\u6570]\u3068\u306a\u308a\u307e\u3059\u3002\u30ea\u30c6\u30e9\u30eb\u6587\u5b57\u306f\u5909\u66f4\u51fa\u6765\u307e\u305b\u3093\u306e\u3067\u3001”char const”\u578b\u3067\u3059\u3002\u5f93\u3063\u3066\u3001”char const (&)[6]”\u3068\u306a\u308a\u307e\u3059\u3002<\/p>\n
\u305d\u3057\u3066\u3001\u5f8c\u8005\u306econst\u53c2\u7167\u3067\u53d7\u3051\u53d6\u3089\u306a\u3044\u5834\u5408\u306f\u3001\u914d\u5217\u306f\u5148\u982d\u3078\u306e\u30dd\u30a4\u30f3\u30bf\u3067\u53d7\u3051\u53d6\u308a\u307e\u3059\u306e\u3067\u3001char const*\u3068\u306a\u308a\u307e\u3059\u3002
\n\u6587\u5b57\u5217\u81ea\u4f53\u306f\u30b3\u30d4\u30fc\u3057\u3066\u3044\u306a\u3044\u306e\u3067\u30b3\u30d4\u30fc\u30b3\u30b9\u30c8\u304c\u7121\u8996\u3067\u304d\u3066\u3057\u307e\u3044\u307e\u3059\u304c\u3001\u3082\u3057\u3001std::string\u3092\u6e21\u3057\u3066\u30b3\u30d4\u30fc\u3059\u308b\u3068\u30b3\u30d4\u30fc\u30b3\u30b9\u30c8\u304c\u6c17\u306b\u306a\u308a\u307e\u3059\u3002\uff08\u30d2\u30fc\u30d7\u30e1\u30e2\u30ea\u7372\u5f97\u30b3\u30b9\u30c8\u3082\u304b\u304b\u308a\u307e\u3059\u3057\u3002\uff09<\/p><\/blockquote>\n
Wandbox\u3067\u78ba\u8a8d\u3059\u308b\u3002<\/a><\/p>\n
1-2.\u95a2\u6570\u30d1\u30e9\u30e1\u30fc\u30bf\u30fb\u30d1\u30c3\u30af\u306e\u52a0\u5de5<\/h3>\n
\u30eb\u30fc\u30eb\u306f\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30fb\u30d1\u30e9\u30e1\u30fc\u30bf\u30fb\u30d1\u30c3\u30af\u306e\u52a0\u5de5\u3068\u540c\u3058\u3067\u3059\u3002\u95a2\u6570\u30d1\u30e9\u30e1\u30fc\u30bf\u30fb\u30d1\u30c3\u30af\u540d\u306b\u52a0\u5de5\u3092\u65bd\u3057\u3066\u3001\u5f8c\u308d\u306b...<\/code>\u3092\u4ed8\u3051\u308b\u3060\u3051\u3067\u3059\u3002<\/p>\n
\u3053\u306e\u52a0\u5de5\u306f\u3073\u3063\u304f\u308a\u9ad8\u5ea6\u306a\u52a0\u5de5\u304c\u3067\u304d\u307e\u3059\u3002\u4f8b\u3048\u3070\u95a2\u6570\u547c\u3073\u51fa\u3057\u3082\u3067\u304d\u307e\u3059\u3002
\n\u30b5\u30f3\u30d7\u30eb\u3092\u95a2\u6570\u547c\u3073\u51fa\u3057\u3067\u51e6\u7406\u3057\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n
\r\n#include <iostream>\r\n#include "typename.h"\r\n\r\ntemplate<typename tType>\r\nstruct Type { };\r\n\r\ntemplate<typename... tTypes>\r\nvoid printLogImpl(tTypes const&...)\r\n{\r\n}\r\n \r\ntemplate<typename... tTypes>\r\nvoid printLog(tTypes const&... iParams)\r\n{\r\n    printLogImpl(std::cout << iParams  << " [" << TYPENAME(Type<decltype(iParams)>) << "]\\n"...);\r\n}\r\n  \r\nint main()\r\n{\r\n    printLog(1, 1.2, "three");\r\n}\r\n<\/pre>\n
\u3053\u306e\u7d50\u679c\u306fWandbox\u306egcc\u3067\u306f\u6b21\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3057\u305f\u3002<\/p>\n
\r\nthree [Type<char const (&) [6]>]\r\n1.2 [Type<double const&>]\r\n1 [Type<int const&>]\r\n<\/pre>\n
Wandbox\u3067\u78ba\u8a8d\u3059\u308b\u3002<\/a><\/p>\n
\u671f\u5f85\u3057\u305f\u306e\u3068\u306f\u9806\u5e8f\u304c\u9006\u3067\u3059\u304c\u3001\u6e21\u3057\u305f\u30d1\u30e9\u30e1\u30fc\u30bf\u5168\u3066\u306b\u5bfe\u3057\u3066print()\u95a2\u6570\u304c\u547c\u3070\u308c\u3066\u3044\u307e\u3059\u3002
\nprintLogImpl()\u306fprintLog()\u3068\u540c\u3058\u5f62\u5f0f\u306a\u306e\u3067\u3001\u3044\u304f\u3089\u3067\u3082\u30d1\u30e9\u30e1\u30fc\u30bf\u3092\u6e21\u305b\u307e\u3059\u3002\u305d\u3053\u306b\u3001\u95a2\u6570\u30d1\u30e9\u30e1\u30fc\u30bf\u30fb\u30d1\u30c3\u30af\u3092\u52a0\u5de5\u3057\u3066\u6e21\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n
\u305d\u306e\u7d50\u679c\u3001main()\u95a2\u6570\u304b\u3089\u306eprintLog(1, 1.2, \"three\");<\/code>\u547c\u3073\u51fa\u3057\u306f\u3001\u30b3\u30f3\u30d1\u30a4\u30e9\u304c\u6b21\u306e\u3088\u3046\u306b\u5c55\u958b\u3057\u3001\u5168\u3066\u306e\u30d1\u30e9\u30e1\u30fc\u30bf\u304c\u51e6\u7406\u3055\u308c\u307e\u3059\u3002<\/p>\n
\r\nprintLogImpl\r\n(\r\n    std::cout << 1 << " [" << TYPENAME(Type<decltype(1)>) << "]\\n",\r\n    std::cout << 1.2 << " [" << TYPENAME(Type<decltype(1.2)>) << "]\\n",\r\n    std::cout << "three" << " [" << TYPENAME(Type<decltype("three")>) << "]\\n"\r\n);\r\n<\/pre>\n
\u3057\u304b\u3057\u3001\u9006\u306b\u306a\u3063\u3066\u3057\u307e\u3046\u306e\u306f\u4f55\u6545\u3067\u3057\u3087\u3046\uff1f
\n\u95a2\u6570\u547c\u3073\u51fa\u3057\u306e\u30d1\u30e9\u30e1\u30fc\u30bf\u306e\u8a55\u4fa1\u9806\u5e8f\u306f\u898f\u5b9a\u3055\u308c\u3066\u3044\u307e\u305b\u3093\u3002\u30b3\u30f3\u30d1\u30a4\u30e9\u3092\u66f8\u3044\u305f\u4eba\u304c\u81ea\u7531\u306b\u6c7a\u3081\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u30d1\u30e9\u30e1\u30fc\u30bf\u306f\u30b9\u30bf\u30c3\u30af\u306b\u7a4d\u307e\u308c\u308b\u51e6\u7406\u7cfb\u304c\u591a\u3044\u306e\u3067\u3059\u304c\u3001\u305d\u306e\u969b\u3001\u5f8c\uff08\u53f3\uff09\u304b\u3089\u9806\u306b\u7a4d\u3093\u3067\u3044\u304f\u3068\u3001\u6700\u521d\u306e\u30d1\u30e9\u30e1\u30fc\u30bf\u304c\u30a2\u30c9\u30ec\u30b9\u304c\u4e00\u756a\u82e5\u3044\u3068\u3053\u308d\u306b\u7a4d\u307e\u308c\u308b\u306e\u3067\u51e6\u7406\u3057\u3084\u3059\u3044\u3067\u3059\u3002\u305d\u306e\u305f\u3081\u3001\u5f8c\u304b\u3089\u9806\u306b\u7a4d\u3080\u51e6\u7406\u7cfb\u304c\u591a\u3044\u3067\u3059\u3002\u305d\u3057\u3066\u3001\u30b9\u30bf\u30c3\u30af\u306b\u7a4d\u3080\u76f4\u524d\u306b\u51e6\u7406\u3059\u308b\u3068\u90fd\u5408\u304c\u826f\u3044\u306e\u3067\u3059\u3002\u305d\u306e\u7d50\u679c\u3001\u95a2\u6570\u306b\u6e21\u3059\u30d1\u30e9\u30e1\u30fc\u30bf\u304c\u5f8c\u304b\u3089\u8a55\u4fa1\u3055\u308c\u308b\u51e6\u7406\u7cfb\u304c\u5c11\u306a\u304f\u3042\u308a\u307e\u305b\u3093\u3002<\/p>\n
\u3068\u3053\u308d\u3067\u3001\u3088\u304f\u898b\u308b\u3068\u518d\u5e30\u304c\u306a\u304f\u306a\u3063\u3066\u307e\u3059\u306d\u3002\u305d\u3046\u3001\u95a2\u6570\u30d1\u30e9\u30e1\u30fc\u30bf\u30fb\u30d1\u30c3\u30af\u3092\u5c55\u958b\u3059\u308b\u969b\u306b\u95a2\u6570\u547c\u51fa\u3057\u3059\u308b\u3088\u3046\u306b\u52a0\u5de5\u3059\u308c\u3070\u3001\u6e21\u3055\u308c\u305f\u5168\u3066\u306e\u30d1\u30e9\u30e1\u30fc\u30bf\u3092\u51e6\u7406\u3067\u304d\u308b\u308f\u3051\u3067\u3059\u3002\u306a\u3093\u3060\u518d\u5e30\u3057\u306a\u304f\u3066\u3082\u51e6\u7406\u3067\u304d\u308b\u306e\u3067\u3059\u306d\u3002<\/p>\n
\uff12\uff0e\u518d\u5e30\u3092\u4f7f\u308f\u306a\u3044\u3067\u95a2\u6570\u30d1\u30e9\u30e1\u30fc\u30bf\u30fb\u30d1\u30c3\u30af\u3092\u5c55\u958b\u3059\u308b\u65b9\u6cd5<\/h3>\n
1-2.\u306e\u95a2\u6570\u547c\u3073\u51fa\u3057\u3067\u5c55\u958b\u3059\u308b\u3068\u51e6\u7406\u9806\u5e8f\u304c\u51e6\u7406\u7cfb\u306b\u4f9d\u5b58\u3057\u3066\u3057\u307e\u3044\u3001\u591a\u304f\u306e\u51e6\u7406\u7cfb\u3067\u306f\u9006\u9806\u306b\u51e6\u7406\u3055\u308c\u3066\u3057\u307e\u3044\u307e\u3059\u3002\u3067\u304d\u308c\u3070\u3001\u51e6\u7406\u7cfb\u306b\u4f9d\u5b58\u305b\u305a\u982d\u304b\u3089\u9806\u756a\u306b\u51e6\u7406\u3057\u305f\u3044\u3067\u3059\u3002<\/p>\n
\u30cd\u30c3\u30c8\u3092\u63a2\u3057\u3066\u3044\u308b\u3068\u3042\u308a\u307e\u3057\u305f\uff01\uff01
\nC++\u306e\u30d1\u30e9\u30e1\u30fc\u30bf\u30d1\u30c3\u30af\u57fa\u790e&\u30d1\u30c3\u30af\u5c55\u958b\u30c6\u30af\u30cb\u30c3\u30af<\/a>\u306e\u8a18\u4e8b\u306b\u3088\u308b\u3068Swallow<\/a>\u3068\u547c\u3070\u308c\u308b\u30c6\u30af\u30cb\u30c3\u30af\uff08\u30a4\u30c7\u30aa\u30e0\uff1f\uff09\u3092\u4f7f\u3046\u3068\u304a\u624b\u8efd\u304b\u3064\u30b9\u30de\u30fc\u30c8\u306b\u5c55\u958b\u3067\u304d\u307e\u3059\u3002<\/p>\n
\u3053\u306e\u8a18\u4e8b\u3067\u306f\u3001std::initializer_list\u3092\u4f7f\u3063\u3066\u307e\u3059\u304c\u3001\u79c1\u3068\u3057\u3066\u306f\u914d\u5217\u3092\u521d\u671f\u5316\u3059\u308b\u65b9\u6cd5\u3092\u304a\u52e7\u3081\u3057\u307e\u3059\u3002\u8ffd\u52a0\u306e\u30a4\u30f3\u30af\u30eb\u30fc\u30c9\u4e0d\u8981\u3067\u3001\u5fc5\u8981\u306a\u90e8\u5206\u3060\u3051\u306b\u8a18\u8ff0\u3059\u308c\u3070\u826f\u3044\u306e\u3067\u304a\u624b\u8efd\u3067\u3059\u3057\u3001\u8a18\u8ff0\u91cf\u3082\u5c11\u306a\u3044\u3067\u3059\u304b\u3089\u898b\u901a\u3057\u3082\u826f\u3044\u3067\u3059\u3002<\/p>\n
2-1.Swallow\uff08\u98f2\u307f\u8fbc\u3080\uff09\u30c6\u30af\u30cb\u30c3\u30af\u306b\u3064\u3044\u3066<\/span><\/h4>\n
\u307e\u305a\u306f\u3001\u3042\u307e\u308a\u77e5\u3089\u308c\u3066\u3044\u306a\u3044 , \u30ab\u30f3\u30de\u6f14\u7b97\u5b50\u3067\u3059\u3002+ \u3084 – \u306a\u3069\u3068\u540c\u3058\u304f\u5f0f\u306e\u4e2d\u3067\u4f7f\u3048\u307e\u3059\u3002
\n, \u3067\u533a\u5207\u3063\u3066\u8907\u6570\u306e\u90e8\u5206\u5f0f\u3092\u66f8\u304f\u3053\u3068\u304c\u3067\u304d\u3001\u305d\u306e\u7d50\u679c\u306f\u6700\u5f8c\u306b\u66f8\u3044\u305f\u90e8\u5206\u5f0f\u306e\u5024\u3068\u306a\u308a\u307e\u3059\u3002<\/p>\n
\r\nint x = (1+2, 0);\r\nstd::cout << x << "\\n";\r\n<\/pre>\n
\u30ab\u30f3\u30de\u6f14\u7b97\u5b50\u306e\u512a\u5148\u9806\u4f4d\u306f\u975e\u5e38\u306b\u4f4e\u3044<\/a>\u306e\u3067\u591a\u304f\u306e\u5834\u5408\u3001()\u3067\u62ec\u3089\u306a\u3044\u3068\u30b3\u30f3\u30d1\u30a4\u30eb\u30a8\u30e9\u30fc\u306b\u306a\u3063\u305f\u308a\u3001\u610f\u56f3\u3057\u306a\u3044\u7d50\u679c\u306b\u306a\u3063\u305f\u308a\u3057\u307e\u3059\u306e\u3067\u3001\u6ce8\u610f\u304c\u5fc5\u8981\u3067\u3059\u3002<\/p>\n
\r\n0\r\n<\/pre>\n
\uff08\u4e0a\u8a18\u306e\u5f0f\u306fgcc\u3067\u306f\u300c\u30ab\u30f3\u30de\u306e\u5de6\u5074\u306f\u4f55\u306e\u52b9\u679c\u3082\u306a\u3044\u300d\u306e\u610f\u5473\u306e\u8b66\u544a\u304c\u3067\u307e\u3059\u3002\u305d\u306e\u901a\u308a\u3067\u3059\u306d\u3002\u3067\u3082\u3001\u4eca\u306f\u6c17\u306b\u3057\u306a\u3044\u3067\u304f\u3060\u3055\u3044\u3002\uff09<\/p>\n
\u3055\u3066\u3001\u4e0a\u8a18\u306e 1+2 \u306e\u90e8\u5206\u306b\u5f0f\u3092\u66f8\u3051\u308b\u3068\u3044\u3046\u3053\u3068\u306f\u3001\u95a2\u6570\u3092\u547c\u3073\u51fa\u3057\u305f\u308a\u3001std::cout << 123<\/code>\u3068\u66f8\u3044\u305f\u308a\u3067\u304d\u307e\u3059\u3002\u5f8c\u8005\u306f\u6587\u306e\u3088\u3046\u306b\u898b\u3048\u307e\u3059\u304c\u3001\u5f0f\u3067\u3059\u3002 std::ostream\u306eoperator<<()<\/code>\u3068\u3044\u3046\u95a2\u6570\u3092\u547c\u3073\u51fa\u3057\u307e\u3059\u3002\u3053\u306e\u95a2\u6570\u306fstd::ostream\u306e\u53c2\u7167\u3092\u8fd4\u5374\u3057\u307e\u3059\u3002<\/p>\n
\r\nint x = (std::cout << 1+2 << "\\n", 0);\r\nstd::cout << x << "\\n";\r\n<\/pre>\n
x\u3092(std::cout << 1+2 << \"\\n\", 0)<\/code>\u3067\u521d\u671f\u5316\u3057\u307e\u3059\u3002\u305d\u306e\u6642\u3001std::cout << 1+2 << \"\\n\"<\/code>\u304c\u5b9f\u884c\u3055\u308c\u3001\u305d\u306e\u5f8c\u30ab\u30f3\u30de\u306e\u53f3\u5074\u306e\u50240\u304cx\u306b\u521d\u671f\u8a2d\u5b9a\u3055\u308c\u307e\u3059\u3002<\/p>\n
\r\n3\r\n0\r\n<\/pre>\n
\uff08\u56e0\u307f\u306b\u3001\u4eca\u5ea6\u306f\u30ab\u30f3\u30de\u306e\u5de6\u5074\u306f\u305d\u308c\u306a\u308a\u306b\u51e6\u7406\u3092\u3057\u3066\u3044\u308b\u306e\u3067\u300c\u4f55\u306e\u52b9\u679c\u3082\u306a\u3044\u300d\u8b66\u544a\u306f\u3067\u307e\u305b\u3093\u3002\uff09<\/p>\n
\u6b21\u306b\u3001\u914d\u5217\u306e\u521d\u671f\u5316\u306f\u6b21\u306e\u3088\u3046\u306b\u66f8\u3051\u307e\u3059\u306d\u3002<\/p>\n
\r\nint dummy[]\r\n{\r\n    1,\r\n    2,\r\n    3\r\n};\r\n<\/pre>\n
\u3053\u308c\u306e\u5404\u8981\u7d20\uff081, 2, 3\uff09\u306e\u90e8\u5206\u306b\u5148\u7a0b\u306e\u30ab\u30f3\u30de\u6f14\u7b97\u5b50\u3092\u306f\u3081\u8fbc\u3093\u3067\u307f\u307e\u3059\u3002<\/p>\n
\r\nint dummy[]\r\n{\r\n    (std::cout << 10 << "\\n", 1),\r\n    (std::cout << 20 << "\\n", 2),\r\n    (std::cout << 30 << "\\n", 3)\r\n};\r\nfor (auto x : dummy)\r\n{\r\n    std::cout << x << "\\n";\r\n}\r\n<\/pre>\n
\r\n10\r\n20\r\n30\r\n1\r\n2\r\n3\r\n<\/pre>\n
\u3053\u306e\u3088\u3046\u306b\u5b9f\u884c\u9806\u5e8f\u306f\u5b9a\u7fa9\u9806\u3068\u306a\u308a\u307e\u3059\u3002\u3053\u308c\u306f\u914d\u5217\u306e\u521d\u671f\u5316\u5b50\u306e\u8a55\u4fa1\u9806\u3067\u3059\u306e\u3067\u6a19\u6e96\u898f\u683c\u4e0a\u4fdd\u8a3c\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n
\u3055\u3066\u3001\u3053\u306edummy\u306f\u5b9f\u4f53\u306b\u540d\u524d\u3092\u4ed8\u3051\u3066\u3044\u308b\u306e\u3067\u5c11\u3057\u9b31\u9676\u3057\u3044\u3067\u3059\u3002\u4f3c\u305f\u3088\u3046\u306a\u8907\u6570\u306e\u51e6\u7406\u3092\u540c\u3058{}\u30d6\u30ed\u30c3\u30af\u5185\u3067\u5b9f\u88c5\u3059\u308b\u5834\u5408\u3001\u7570\u306a\u308b\u540d\u524d\u3092\u4ed8\u3051\u305f\u308a\u3001{}\u30d6\u30ed\u30c3\u30af\u3067\u6539\u3081\u3066\u56f2\u3093\u3060\u308a\u3059\u308b\u3053\u3068\u306b\u306a\u308a\u307e\u3059\u3002
\nint[]{1, 2, 3};<\/code>\u304c\u3067\u304d\u308c\u3070\u826f\u3044\u306e\u3067\u3059\u304c\u3001\u3053\u308c\u306f\u3069\u3046\u3084\u3089\u3067\u304d\u306a\u3044\u3088\u3046\u3067\u3059\u3002
\n\u3057\u304b\u3057\u3001\u578b\u540d\u306b\u540d\u524d\u3092\u3064\u3051\u308c\u3070\u826f\u3044\u307f\u305f\u3044\u3067\u3059\u3002\uff08\u578b\u540d\u306f\u4f7f\u3044\u56de\u3057\u3067\u304d\u307e\u3059\u3002\uff09<\/p>\n
\r\nusing swallow=int[];\r\nswallow\r\n{\r\n    (std::cout << 10 << "\\n", 0),\r\n    (std::cout << 20 << "\\n", 0),\r\n    (std::cout << 30 << "\\n", 0)\r\n};\r\n<\/pre>\n
gcc\u3067\u306f\u8b66\u544a\u306f\u3067\u306a\u3044\u306e\u3067\u3059\u304c\u3001clang\u3067\u306f\u300c\u914d\u5217\u3092\u5b9a\u7fa9\u3057\u305f\u3051\u3069\u4f7f\u3063\u3066\u3044\u306a\u3044\u300d\u65e8\u306e\u8b66\u544a\u304c\u3067\u308b\u3088\u3046\u3067\u3059\u3002\u78ba\u304b\u306b\u305d\u306e\u901a\u308a\u3067\u3059\u306d\u3002void\u3067\u30ad\u30e3\u30b9\u30c8\u3059\u308b\u3053\u3068\u3067\u8b66\u544a\u3092\u6d88\u305b\u307e\u3059\u3002C\u8a00\u8a9e\u30b9\u30bf\u30a4\u30eb\u306e\u30ad\u30e3\u30b9\u30c8\u306f\u3042\u307e\u308a\u4f7f\u308f\u306a\u3044\u65b9\u304c\u3088\u3044\u306e\u3067\u3059\u304c\u3001\u30ad\u30e3\u30b9\u30c8\u3057\u305f\u7d50\u679c\u3092\u4f7f\u3046\u308f\u3051\u3067\u306f\u306a\u3044\u306e\u3067\u30b9\u30c3\u30ad\u30ea\u8a18\u8ff0\u3059\u308b\u305f\u3081\u306bC\u30b9\u30bf\u30a4\u30eb\u3067\u30ad\u30e3\u30b9\u30c8\u3057\u3066\u307e\u3059\u3002<\/p>\n
\r\n#include <iostream>\r\n\r\nint main()\r\n{\r\n    using swallow=int[];\r\n    (void)swallow\r\n    {\r\n        (std::cout << 10 << "\\n", 0),\r\n        (std::cout << 20 << "\\n", 0),\r\n        (std::cout << 30 << "\\n", 0)\r\n    };\r\n}\r\n<\/pre>\n
\r\n10\r\n20\r\n30\r\n<\/pre>\n
Wandbox\u3067\u78ba\u8a8d\u3059\u308b\u3002<\/a><\/p>\n
2-2.Swallow\u30c6\u30af\u30cb\u30c3\u30af\u3092\u4f7f\u3063\u3066\u95a2\u6570\u30d1\u30e9\u30e1\u30fc\u30bf\u30fb\u30d1\u30c3\u30af\u3092\u5c55\u958b\u3059\u308b<\/h4>\n
\u3053\u3053\u307e\u3067\u898b\u308c\u3070\u3060\u3044\u305f\u3044\u898b\u5f53\u304c\u4ed8\u304f\u304b\u3068\u601d\u3044\u307e\u3059\u304c\u3001\u95a2\u6570\u30d1\u30e9\u30e1\u30fc\u30bf\u30fb\u30d1\u30c3\u30af\u3092\u4e0a\u8a18\u30c6\u30af\u30cb\u30c3\u30af\u306b\u3066\u5c55\u958b\u3057\u3066\u307f\u307e\u3059\u3002<\/p>\n
\r\n#include <iostream>\r\n#include "typename.h"\r\n\r\ntemplate<typename tType>\r\nstruct Type { };\r\n \r\ntemplate<typename... tTypes>\r\nvoid printLog(tTypes const&... iParams)\r\n{\r\n    using swallow = int[];\r\n    (void)swallow\r\n    {\r\n        (std::cout << iParams  << " [" << TYPENAME(Type<decltype(iParams)>) << "]\\n", 0)...\r\n    };\r\n}\r\n  \r\nint main()\r\n{\r\n    printLog(1, 1.2, "three");\r\n}\r\n<\/pre>\n
\r\n1 [Type<int const&>]\r\n1.2 [Type<double const&>]\r\nthree [Type<char const (&) [6]>]\r\n<\/pre>\n
\u30ab\u30f3\u30de\u533a\u5207\u308a\u3067\uff11\u884c\u306b\u53ce\u3081\u308b\u3053\u3068\u3082\u3067\u304d\u307e\u3059\u3002\uff08TYPENAME\u304c\u3042\u308b\u3068\u898b\u306b\u304f\u3044\u306e\u3067\u524a\u9664\uff09<\/p>\n
\r\n#include <iostream>\r\n\r\ntemplate<typename... tTypes>\r\nvoid printLog(tTypes const&... iParams)\r\n{\r\n    bool first=true;\r\n    using swallow = int[];\r\n    (void)swallow\r\n    {\r\n        (std::cout << (first?"":", ") << iParams, first=false, 0)...\r\n    };\r\n    std::cout << "\\n";\r\n}\r\n  \r\nint main()\r\n{\r\n    printLog(1, 1.2, "three");\r\n}\r\n<\/pre>\n
\r\n1, 1.2, three\r\n<\/pre>\n
Wandbox\u3067\u78ba\u8a8d\u3059\u308b\u3002<\/a><\/p>\n
\uff13\uff0e\u307e\u3068\u3081<\/h3>\n
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