{"height":"190","published":"2022-12-19 11:55:25","type":"rich","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Ftarao.hatenablog.com%2Fentry%2Fsubtyping-polarity\" title=\"\u90e8\u5206\u578b\u306b\u304a\u3051\u308b\u5909\u6027\u3068\u6975\u6027 - \u306a\u305cScala\u306e\u5909\u6027\u306f+\u3084-\u3067\u6307\u5b9a\u3059\u308b\u306e\u304b - \u8cb3\u4f70\u4f0d\u62fe\u9678\u591c\u65e5\u8a18\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","blog_title":"\u8cb3\u4f70\u4f0d\u62fe\u9678\u591c\u65e5\u8a18","author_name":"tarao","categories":["lang","scala","article"],"description":"\u3053\u306e\u8a18\u4e8b\u306fScala Advent Calendar 2022\u306e19\u65e5\u76ee\u3067\u3059.Scala\u3067\u306f\u30b8\u30a7\u30cd\u30ea\u30c3\u30af\u578b\u306e\u5909\u6027(variance)\u306f+\u3084-\u3067\u6307\u5b9a\u3057\u307e\u3059\u304c, \u4ed6\u306e\u8a00\u8a9e(\u305f\u3068\u3048\u3070, C#, Kotlin)\u3067\u306fout\u3084in\u3060\u3063\u305f\u308a\u3057\u307e\u3059. \u3053\u306e\u8a18\u4e8b\u3067\u306f\u5909\u6027\u306e\u610f\u5473\u3092\u6574\u7406\u3057\u3066, \u306a\u305cScala\u3067\u306f+/-\u306e\u8a18\u53f7\u3092\u4f7f\u3046\u306e\u304b\u8aac\u660e\u3057\u307e\u3059.\u8ffd\u8a18\u305f\u3060\u3057, \u3053\u3053\u3067\u8aac\u660e\u3057\u3066\u3044\u308b\u5185\u5bb9\u306f\u57fa\u672c\u7684\u306bC#\u3084Kotlin\u3067\u3082\u6210\u7acb\u3059\u308b(\u306f\u305a\u306a)\u306e\u3067\u300c\u306a\u305c\u3053\u308c\u3089\u306e\u8a00\u8a9e\u3067\u306f+/-\u306e\u8a18\u53f7\u3092\u4f7f\u308f\u306a\u3044\u306e\u304b\u300d\u3092\u8aac\u660e\u3059\u308b\u3082\u306e\u3067\u306f\u3042\u308a\u307e\u305b\u3093. \u500b\u4eba\u7684\u306b\u306f+/-\u306e\u65b9\u304c\u308f\u304b\u308a\u3084\u3059\u3044\u3068\u601d\u3046\u3057, out/in\u306e\u8a18\u6cd5\u306f\u6271\u3063\u3066\u3044\u308b\u6982\u5ff5\u304c\u7c21\u5358\u3067\u3042\u308b\u304b\u306e\u3088\u3046\u306a\u8aa4\u2026","blog_url":"https://tarao.hatenablog.com/","image_url":"https://cdn-ak.f.st-hatena.com/images/fotolife/t/tarao/20221219/20221219115117.png","version":"1.0","author_url":"https://blog.hatena.ne.jp/tarao/","title":"\u90e8\u5206\u578b\u306b\u304a\u3051\u308b\u5909\u6027\u3068\u6975\u6027 - \u306a\u305cScala\u306e\u5909\u6027\u306f+\u3084-\u3067\u6307\u5b9a\u3059\u308b\u306e\u304b","url":"https://tarao.hatenablog.com/entry/subtyping-polarity","provider_url":"https://hatena.blog","provider_name":"Hatena Blog","width":"100%"}