{"url":"https://secret-garden.hatenablog.com/entry/2019/12/16/001023","author_url":"https://blog.hatena.ne.jp/osyo-manga/","provider_url":"https://hatena.blog","title":"\u3010\u4e00\u4eba C++20 Advent Calendar 2019\u3011dynamic_cast \u304c constexpr \u306b\u5bfe\u5fdc\u301016\u65e5\u76ee\u3011","blog_url":"https://secret-garden.hatenablog.com/","height":"190","image_url":null,"published":"2019-12-16 00:10:23","width":"100%","provider_name":"Hatena Blog","type":"rich","blog_title":"Secret Garden(Instrumental)","categories":["C++","C++20"],"version":"1.0","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fsecret-garden.hatenablog.com%2Fentry%2F2019%2F12%2F16%2F001023\" title=\"\u3010\u4e00\u4eba C++20 Advent Calendar 2019\u3011dynamic_cast \u304c constexpr \u306b\u5bfe\u5fdc\u301016\u65e5\u76ee\u3011 - Secret Garden(Instrumental)\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","author_name":"osyo-manga","description":"\u4e00\u4eba C++20 Advent Calendar 2019 16\u65e5\u76ee\u306e\u8a18\u4e8b\u306b\u306a\u308a\u307e\u3059\u3002 dynamic_cast \u304c constexpr \u306b\u5bfe\u5fdc dynamic_cast \u304c constexpr \u306b\u5bfe\u5fdc\u3057\u307e\u3057\u305f\u3002 #include <iostream> struct A { virtual void dummy(){} }; struct B : A { constexpr B(int value) : value(value) {} virtual int get() { return value; } int value; }; struct C {}; int main(){ stati\u2026"}