{"blog_url":"https://djann-prog.hatenablog.com/","type":"rich","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fdjann-prog.hatenablog.com%2Fentry%2F2015%2F07%2F25%2F162313\" title=\"\u305d\u308c\u3067\u3082decltype\u306e\u6319\u52d5\u306f\u8b0e\u3067\u3042\u308b - \u4e26\u30b2\u30fc\u30e0\u30d7\u30ed\u30b0\u30e9\u30de\u306e\u66f8\u304d\u6368\u3066\u5834\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","description":"\u8cb4\u65b9\u306f\u3053\u3046\u3044\u3046\u4eba\u3067\u3059\u306d\uff1fdjann\u3067\u3059\u3002 depot\u306b\u306f\u73fe\u5728with_state_value\u3068\u3044\u3046\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u304c\u5b58\u5728\u3059\u308b\u3002boost\u306b\u5b58\u5728\u3057\u3001C++17\u3067\u6a19\u6e96\u5165\u308a\u3055\u308c\u308b\u3068\u3044\u308f\u308c\u3066\u3044\u308boptional\u306e\u8868\u9762\u7684\u306a\u6982\u5ff5\u3092\u53d6\u308a\u5165\u308c\u305f\u3082\u306e\u3067\u3001\u6307\u5b9a\u3057\u305f\u578b\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3068\u3001\u305d\u306e\u6709\u52b9\u72b6\u614b\u3092\u4fdd\u6301\u3059\u308b\u3082\u306e\u3060\u3002\u4f8b depot::with_state_value<int> val; if ( val ){ // unreachable. std::cout << \"available : \" << *val << std::endl; } else { std::cout << \"unavailable.\" << s\u2026","provider_name":"Hatena Blog","version":"1.0","provider_url":"https://hatena.blog","url":"https://djann-prog.hatenablog.com/entry/2015/07/25/162313","height":"190","image_url":null,"author_name":"djann","width":"100%","published":"2015-07-25 16:23:13","title":"\u305d\u308c\u3067\u3082decltype\u306e\u6319\u52d5\u306f\u8b0e\u3067\u3042\u308b","categories":["C++","\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0","\u96d1\u8a18"],"author_url":"https://blog.hatena.ne.jp/djann/","blog_title":"\u4e26\u30b2\u30fc\u30e0\u30d7\u30ed\u30b0\u30e9\u30de\u306e\u66f8\u304d\u6368\u3066\u5834"}