49 lines
8.1 KiB
HTML
49 lines
8.1 KiB
HTML
<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="API documentation for the Rust `decl_derive` macro in crate `synstructure`."><meta name="keywords" content="rust, rustlang, rust-lang, decl_derive"><title>synstructure::decl_derive - Rust</title><link rel="stylesheet" type="text/css" href="../normalize.css"><link rel="stylesheet" type="text/css" href="../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" type="text/css" href="../dark.css"><link rel="stylesheet" type="text/css" href="../light.css" id="themeStyle"><script src="../storage.js"></script><noscript><link rel="stylesheet" href="../noscript.css"></noscript><link rel="shortcut icon" href="../favicon.ico"><style type="text/css">#crate-search{background-image:url("../down-arrow.svg");}</style></head><body class="rustdoc macro"><!--[if lte IE 8]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="sidebar-menu">☰</div><a href='../synstructure/index.html'><div class='logo-container'><img src='../rust-logo.png' alt='logo'></div></a><div class="sidebar-elems"><p class='location'><a href='index.html'>synstructure</a></p><script>window.sidebarCurrent = {name: 'decl_derive', ty: 'macro', relpath: ''};</script><script defer src="sidebar-items.js"></script></div></nav><div class="theme-picker"><button id="theme-picker" aria-label="Pick another theme!"><img src="../brush.svg" width="18" alt="Pick another theme!"></button><div id="theme-choices"></div></div><script src="../theme.js"></script><nav class="sub"><form class="search-form"><div class="search-container"><div><select id="crate-search"><option value="All crates">All crates</option></select><input class="search-input" name="search" disabled autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"></div><a id="settings-menu" href="../settings.html"><img src="../wheel.svg" width="18" alt="Change settings"></a></div></form></nav><section id="main" class="content"><h1 class='fqn'><span class='out-of-band'><span id='render-detail'><a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class='inner'>−</span>]</a></span><a class='srclink' href='../src/synstructure/macros.rs.html#88-108' title='goto source code'>[src]</a></span><span class='in-band'>Macro <a href='index.html'>synstructure</a>::<wbr><a class="macro" href=''>decl_derive</a></span></h1><div class="docblock type-decl hidden-by-usual-hider"><div class="example-wrap"><pre class="rust macro">
|
||
<span class="macro">macro_rules</span><span class="macro">!</span> <span class="ident">decl_derive</span> {
|
||
([<span class="macro-nonterminal">$</span><span class="macro-nonterminal">derives</span>:<span class="ident">ident</span> $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">derive_t</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>] <span class="op">=</span><span class="op">></span> $(<span class="attribute">#[$(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">attrs</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>]</span>)<span class="op">*</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">inner</span>:<span class="ident">path</span>) <span class="op">=</span><span class="op">></span> { ... };
|
||
}</pre></div>
|
||
</div><div class='docblock'><p>The <code>decl_derive!</code> macro declares a custom derive wrapper. It will parse the
|
||
incoming <code>TokenStream</code> into a <code>synstructure::Structure</code> object, and pass it
|
||
into the inner function.</p>
|
||
<p>Your inner function should take a <code>synstructure::Structure</code> by value, and
|
||
return a type implementing <code>synstructure::MacroResult</code>, for example:</p>
|
||
|
||
<div class="example-wrap"><pre class="rust rust-example-rendered">
|
||
<span class="kw">fn</span> <span class="ident">derive_simple</span>(<span class="ident">input</span>: <span class="ident">synstructure</span>::<span class="ident">Structure</span>) <span class="op">-</span><span class="op">></span> <span class="ident">proc_macro2</span>::<span class="ident">TokenStream</span> {
|
||
<span class="macro">unimplemented</span><span class="macro">!</span>()
|
||
}
|
||
|
||
<span class="kw">fn</span> <span class="ident">derive_result</span>(<span class="ident">input</span>: <span class="ident">synstructure</span>::<span class="ident">Structure</span>)
|
||
<span class="op">-</span><span class="op">></span> <span class="ident">syn</span>::<span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">proc_macro2</span>::<span class="ident">TokenStream</span><span class="op">></span>
|
||
{
|
||
<span class="macro">unimplemented</span><span class="macro">!</span>()
|
||
}</pre></div>
|
||
<h1 id="usage" class="section-header"><a href="#usage">Usage</a></h1><h3 id="without-attributes" class="section-header"><a href="#without-attributes">Without Attributes</a></h3>
|
||
<div class="example-wrap"><pre class="rust rust-example-rendered">
|
||
<span class="kw">fn</span> <span class="ident">derive_interesting</span>(<span class="ident">_input</span>: <span class="ident">synstructure</span>::<span class="ident">Structure</span>) <span class="op">-</span><span class="op">></span> <span class="ident">proc_macro2</span>::<span class="ident">TokenStream</span> {
|
||
<span class="ident">quote</span>::<span class="macro">quote</span><span class="macro">!</span> { ... }
|
||
}
|
||
|
||
<span class="macro">decl_derive</span><span class="macro">!</span>([<span class="ident">Interesting</span>] <span class="op">=</span><span class="op">></span> <span class="ident">derive_interesting</span>);</pre></div>
|
||
<h3 id="with-attributes" class="section-header"><a href="#with-attributes">With Attributes</a></h3>
|
||
<div class="example-wrap"><pre class="rust rust-example-rendered">
|
||
<span class="kw">fn</span> <span class="ident">derive_interesting</span>(<span class="ident">_input</span>: <span class="ident">synstructure</span>::<span class="ident">Structure</span>) <span class="op">-</span><span class="op">></span> <span class="ident">proc_macro2</span>::<span class="ident">TokenStream</span> {
|
||
<span class="ident">quote</span>::<span class="macro">quote</span><span class="macro">!</span> { ... }
|
||
}
|
||
|
||
<span class="macro">decl_derive</span><span class="macro">!</span>([<span class="ident">Interesting</span>, <span class="ident">attributes</span>(<span class="ident">interesting_ignore</span>)] <span class="op">=</span><span class="op">></span> <span class="ident">derive_interesting</span>);</pre></div>
|
||
<h3 id="decl-attributes--doc-comments" class="section-header"><a href="#decl-attributes--doc-comments">Decl Attributes & Doc Comments</a></h3>
|
||
<div class="example-wrap"><pre class="rust rust-example-rendered">
|
||
<span class="kw">fn</span> <span class="ident">derive_interesting</span>(<span class="ident">_input</span>: <span class="ident">synstructure</span>::<span class="ident">Structure</span>) <span class="op">-</span><span class="op">></span> <span class="ident">proc_macro2</span>::<span class="ident">TokenStream</span> {
|
||
<span class="ident">quote</span>::<span class="macro">quote</span><span class="macro">!</span> { ... }
|
||
}
|
||
|
||
<span class="macro">decl_derive</span><span class="macro">!</span> {
|
||
[<span class="ident">Interesting</span>] <span class="op">=</span><span class="op">></span>
|
||
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">some_lint</span>)]</span>
|
||
<span class="doccomment">/// Documentation Comments</span>
|
||
<span class="ident">derive_interesting</span>
|
||
}</pre></div>
|
||
<p><em>This macro is available if <code>synstructure</code> is built with the <code>"proc-macro"</code>
|
||
feature.</em></p>
|
||
</div></section><section id="search" class="content hidden"></section><section class="footer"></section><script>window.rootPath = "../";window.currentCrate = "synstructure";</script><script src="../aliases.js"></script><script src="../main.js"></script><script defer src="../search-index.js"></script></body></html> |