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Diffstat (limited to 'docs/posts/2021-10-02/cpp-you-can-use-keywords-in-attributes')
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1 files changed, 24 insertions, 24 deletions
diff --git a/docs/posts/2021-10-02/cpp-you-can-use-keywords-in-attributes/index.html b/docs/posts/2021-10-02/cpp-you-can-use-keywords-in-attributes/index.html index 7261530..38c34aa 100644 --- a/docs/posts/2021-10-02/cpp-you-can-use-keywords-in-attributes/index.html +++ b/docs/posts/2021-10-02/cpp-you-can-use-keywords-in-attributes/index.html @@ -15,7 +15,7 @@ <link href="https://blog.nsfisis.dev/custom.css" rel="stylesheet"> <link rel="icon" href="https://blog.nsfisis.dev/favicon.svg"> - <meta name="generator" content="Hugo 0.88.1" /> + <meta name="generator" content="Hugo 0.102.1" /> </head> @@ -47,26 +47,26 @@ 元 URL: <a href="https://qiita.com/nsfisis/items/94090937bcf860cfa93b">https://qiita.com/nsfisis/items/94090937bcf860cfa93b</a></p> <hr> <p>タイトル落ち。まずはこのコードを見て欲しい。</p> -<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4"><code class="language-cpp" data-lang="cpp"><span style="color:#75715e">#include</span> <span style="color:#75715e"><iostream></span><span style="color:#75715e"> -</span><span style="color:#75715e"></span> -<span style="color:#a6e22e">[[alignas]] [[alignof]] [[and]] [[and_eq]] [[asm]] [[auto]] [[bitand]]</span> -<span style="color:#a6e22e">[[bitor]] [[bool]] [[break]] [[case]] [[catch]] [[char]] [[char16_t]]</span> -<span style="color:#a6e22e">[[char32_t]] [[class]] [[compl]] [[const]] [[const_cast]] [[constexpr]]</span> -<span style="color:#a6e22e">[[continue]] [[decltype]] [[default]] [[delete]] [[do]] [[double]]</span> -<span style="color:#a6e22e">[[dynamic_cast]] [[else]] [[enum]] [[explicit]] [[export]] [[extern]] [[false]]</span> -<span style="color:#a6e22e">[[final]] [[float]] [[for]] [[friend]] [[goto]] [[if]] [[inline]] [[int]]</span> -<span style="color:#a6e22e">[[long]] [[mutable]] [[namespace]] [[new]] [[noexcept]] [[not]] [[not_eq]]</span> -<span style="color:#a6e22e">[[nullptr]] [[operator]] [[or]] [[or_eq]] [[override]] [[private]]</span> -<span style="color:#a6e22e">[[protected]] [[public]] [[register]] [[reinterpret_cast]] [[return]] [[short]]</span> -<span style="color:#a6e22e">[[signed]] [[sizeof]] [[static]] [[static_assert]] [[static_cast]] [[struct]]</span> -<span style="color:#a6e22e">[[switch]] [[template]] [[this]] [[thread_local]] [[throw]] [[true]] [[try]]</span> -<span style="color:#a6e22e">[[typedef]] [[typeid]] [[typename]] [[union]] [[unsigned]]</span> -<span style="color:#a6e22e">[[virtual]] [[void]] [[volatile]] [[wchar_t]] [[while]] [[xor]] [[xor_eq]]</span> -<span style="color:#75715e">// [[using]] -</span><span style="color:#75715e"></span><span style="color:#66d9ef">int</span> main() { - std<span style="color:#f92672">::</span>cout <span style="color:#f92672"><<</span> <span style="color:#e6db74">"Hello, World!"</span> <span style="color:#f92672"><<</span> std<span style="color:#f92672">::</span>endl; -} -</code></pre></div><blockquote> +<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-cpp" data-lang="cpp"><span style="display:flex;"><span><span style="color:#75715e">#include</span> <span style="color:#75715e"><iostream></span><span style="color:#75715e"> +</span></span></span><span style="display:flex;"><span><span style="color:#75715e"></span> +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">[[alignas]] [[alignof]] [[and]] [[and_eq]] [[asm]] [[auto]] [[bitand]]</span> +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">[[bitor]] [[bool]] [[break]] [[case]] [[catch]] [[char]] [[char16_t]]</span> +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">[[char32_t]] [[class]] [[compl]] [[const]] [[const_cast]] [[constexpr]]</span> +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">[[continue]] [[decltype]] [[default]] [[delete]] [[do]] [[double]]</span> +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">[[dynamic_cast]] [[else]] [[enum]] [[explicit]] [[export]] [[extern]] [[false]]</span> +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">[[final]] [[float]] [[for]] [[friend]] [[goto]] [[if]] [[inline]] [[int]]</span> +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">[[long]] [[mutable]] [[namespace]] [[new]] [[noexcept]] [[not]] [[not_eq]]</span> +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">[[nullptr]] [[operator]] [[or]] [[or_eq]] [[override]] [[private]]</span> +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">[[protected]] [[public]] [[register]] [[reinterpret_cast]] [[return]] [[short]]</span> +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">[[signed]] [[sizeof]] [[static]] [[static_assert]] [[static_cast]] [[struct]]</span> +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">[[switch]] [[template]] [[this]] [[thread_local]] [[throw]] [[true]] [[try]]</span> +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">[[typedef]] [[typeid]] [[typename]] [[union]] [[unsigned]]</span> +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">[[virtual]] [[void]] [[volatile]] [[wchar_t]] [[while]] [[xor]] [[xor_eq]]</span> +</span></span><span style="display:flex;"><span><span style="color:#75715e">// [[using]] +</span></span></span><span style="display:flex;"><span><span style="color:#75715e"></span><span style="color:#66d9ef">int</span> main() { +</span></span><span style="display:flex;"><span> std<span style="color:#f92672">::</span>cout <span style="color:#f92672"><<</span> <span style="color:#e6db74">"Hello, World!"</span> <span style="color:#f92672"><<</span> std<span style="color:#f92672">::</span>endl; +</span></span><span style="display:flex;"><span>} +</span></span></code></pre></div><blockquote> <p>コンパイラのバージョン $ clang++ –version Apple clang version 11.0.0 (clang-1100.0.33.8) @@ -92,9 +92,9 @@ $ clang++ –std=c++17 hoge.cpp</p> <p>同サイトの [keywords のページ] (<a href="https://en.cppreference.com/w/cpp/keyword">https://en.cppreference.com/w/cpp/keyword</a>) から一覧を拝借し、上のコードが出来上がった (C++17 においてキーワードでないものなど、一部省いている)。 大量の警告 (unknown attribute ‘〇〇’ ignored) がコンパイラから出力されるが、コンパイルできる。</p> <p>上のコードでは <code>[[using]]</code> をコメントアウトしているが、これは <code>using</code> キーワードのみ属性構文の中で意味を持つからであり、このコメントアウトを外すとコンパイルに失敗する。</p> -<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4"><code class="language-cpp" data-lang="cpp"><span style="color:#75715e">// using の例 -</span><span style="color:#75715e"></span><span style="color:#a6e22e">[[using foo: attr1, attr2]] int x; // [[foo::attr1, foo::attr2]]</span> <span style="color:#960050;background-color:#1e0010">の糖衣構文</span> -</code></pre></div><p>C++17 の仕様も見てみる (正確には標準化前のドラフト)。</p> +<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-cpp" data-lang="cpp"><span style="display:flex;"><span><span style="color:#75715e">// using の例 +</span></span></span><span style="display:flex;"><span><span style="color:#75715e"></span><span style="color:#a6e22e">[[using foo: attr1, attr2]] int x; // [[foo::attr1, foo::attr2]]</span> <span style="color:#960050;background-color:#1e0010">の糖衣構文</span> +</span></span></code></pre></div><p>C++17 の仕様も見てみる (正確には標準化前のドラフト)。</p> <p>引用元: <a href="https://timsong-cpp.github.io/cppwp/n4659/dcl.attr#grammar-4">https://timsong-cpp.github.io/cppwp/n4659/dcl.attr#grammar-4</a></p> <blockquote> <p>If a keyword or an alternative token that satisfies the syntactic requirements of an identifier is contained in an attribute-token, it is considered an identifier.</p> |