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HPC-Tools-for-Quantum-Computing


			
				
					
						
						
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							<!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 `proc_macro2` crate."><meta name="keywords" content="rust, rustlang, rust-lang, proc_macro2"><title>proc_macro2 - 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></head><body class="rustdoc mod"><!--[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">&#9776;</div><p class='location'>Crate proc_macro2</p><div class="sidebar-elems"><div class="block items"><ul><li><a href="#modules">Modules</a></li><li><a href="#structs">Structs</a></li><li><a href="#enums">Enums</a></li></ul></div><p class='location'></p><script>window.sidebarCurrent = {name: 'proc_macro2', ty: 'mod', relpath: '../'};</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 js-only"><div class="search-container"><input class="search-input" name="search" autocomplete="off" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><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='in-band'>Crate <a class="mod" href=''>proc_macro2</a></span><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'>&#x2212;</span>]</a></span><a class='srclink' href='../src/proc_macro2/lib.rs.html#1-1075' title='goto source code'>[src]</a></span></h1><div class='docblock'><p>A &quot;shim crate&quot; intended to multiplex the <a href="https://doc.rust-lang.org/proc_macro/"><code>proc_macro</code></a> API on to stable
Rust.</p>
<p>Procedural macros in Rust operate over the upstream
<a href="https://doc.rust-lang.org/proc_macro/struct.TokenStream.html"><code>proc_macro::TokenStream</code></a> type. This type currently is quite
conservative and exposed no internal implementation details. Nightly
compilers, however, contain a much richer interface. This richer interface
allows fine-grained inspection of the token stream which avoids
stringification/re-lexing and also preserves span information.</p>
<p>The upcoming APIs added to <a href="https://doc.rust-lang.org/proc_macro/"><code>proc_macro</code></a> upstream are the foundation for
productive procedural macros in the ecosystem. To help prepare the ecosystem
for using them this crate serves to both compile on stable and nightly and
mirrors the API-to-be. The intention is that procedural macros which switch
to use this crate will be trivially able to switch to the upstream
<code>proc_macro</code> crate once its API stabilizes.</p>
<p>In the meantime this crate also has a <code>nightly</code> Cargo feature which
enables it to reimplement itself with the unstable API of <a href="https://doc.rust-lang.org/proc_macro/"><code>proc_macro</code></a>.
This'll allow immediate usage of the beneficial upstream API, particularly
around preserving span information.</p>
<h1 id="unstable-features" class="section-header"><a href="#unstable-features">Unstable Features</a></h1>
<p><code>proc-macro2</code> supports exporting some methods from <code>proc_macro</code> which are
currently highly unstable, and may not be stabilized in the first pass of
<code>proc_macro</code> stabilizations. These features are not exported by default.
Minor versions of <code>proc-macro2</code> may make breaking changes to them at any
time.</p>
<p>To enable these features, the <code>procmacro2_semver_exempt</code> config flag must be
passed to rustc.</p>
<pre><code class="language-sh">RUSTFLAGS='--cfg procmacro2_semver_exempt' cargo build
</code></pre>
<p>Note that this must not only be done for your crate, but for any crate that
depends on your crate. This infectious nature is intentional, as it serves
as a reminder that you are outside of the normal semver guarantees.</p>
</div><h2 id='modules' class='section-header'><a href="#modules">Modules</a></h2>
<table>
                       <tr class=' module-item'>
                           <td><a class="mod" href="token_stream/index.html"
                                  title='mod proc_macro2::token_stream'>token_stream</a></td>
                           <td class='docblock-short'>
                                <p>Public implementation details for the <code>TokenStream</code> type, such as iterators.</p>

                           </td>
                       </tr></table><h2 id='structs' class='section-header'><a href="#structs">Structs</a></h2>
<table>
                       <tr class=' module-item'>
                           <td><a class="struct" href="struct.Group.html"
                                  title='struct proc_macro2::Group'>Group</a></td>
                           <td class='docblock-short'>
                                <p>A delimited token stream.</p>

                           </td>
                       </tr>
                       <tr class=' module-item'>
                           <td><a class="struct" href="struct.Ident.html"
                                  title='struct proc_macro2::Ident'>Ident</a></td>
                           <td class='docblock-short'>
                                <p>A word of Rust code, which may be a keyword or legal variable name.</p>

                           </td>
                       </tr>
                       <tr class=' module-item'>
                           <td><a class="struct" href="struct.LexError.html"
                                  title='struct proc_macro2::LexError'>LexError</a></td>
                           <td class='docblock-short'>
                                <p>Error returned from <code>TokenStream::from_str</code>.</p>

                           </td>
                       </tr>
                       <tr class=' module-item'>
                           <td><a class="struct" href="struct.Literal.html"
                                  title='struct proc_macro2::Literal'>Literal</a></td>
                           <td class='docblock-short'>
                                <p>A literal string (<code>&quot;hello&quot;</code>), byte string (<code>b&quot;hello&quot;</code>), character (<code>'a'</code>),
byte character (<code>b'a'</code>), an integer or floating point number with or without
a suffix (<code>1</code>, <code>1u8</code>, <code>2.3</code>, <code>2.3f32</code>).</p>

                           </td>
                       </tr>
                       <tr class=' module-item'>
                           <td><a class="struct" href="struct.Punct.html"
                                  title='struct proc_macro2::Punct'>Punct</a></td>
                           <td class='docblock-short'>
                                <p>An <code>Punct</code> is an single punctuation character like <code>+</code>, <code>-</code> or <code>#</code>.</p>

                           </td>
                       </tr>
                       <tr class=' module-item'>
                           <td><a class="struct" href="struct.Span.html"
                                  title='struct proc_macro2::Span'>Span</a></td>
                           <td class='docblock-short'>
                                <p>A region of source code, along with macro expansion information.</p>

                           </td>
                       </tr>
                       <tr class=' module-item'>
                           <td><a class="struct" href="struct.TokenStream.html"
                                  title='struct proc_macro2::TokenStream'>TokenStream</a></td>
                           <td class='docblock-short'>
                                <p>An abstract stream of tokens, or more concretely a sequence of token trees.</p>

                           </td>
                       </tr></table><h2 id='enums' class='section-header'><a href="#enums">Enums</a></h2>
<table>
                       <tr class=' module-item'>
                           <td><a class="enum" href="enum.Delimiter.html"
                                  title='enum proc_macro2::Delimiter'>Delimiter</a></td>
                           <td class='docblock-short'>
                                <p>Describes how a sequence of token trees is delimited.</p>

                           </td>
                       </tr>
                       <tr class=' module-item'>
                           <td><a class="enum" href="enum.Spacing.html"
                                  title='enum proc_macro2::Spacing'>Spacing</a></td>
                           <td class='docblock-short'>
                                <p>Whether an <code>Punct</code> is followed immediately by another <code>Punct</code> or followed by
another token or whitespace.</p>

                           </td>
                       </tr>
                       <tr class=' module-item'>
                           <td><a class="enum" href="enum.TokenTree.html"
                                  title='enum proc_macro2::TokenTree'>TokenTree</a></td>
                           <td class='docblock-short'>
                                <p>A single token or a delimited sequence of token trees (e.g. <code>[1, (), ..]</code>).</p>

                           </td>
                       </tr></table></section><section id="search" class="content hidden"></section><section class="footer"></section><aside id="help" class="hidden"><div><h1 class="hidden">Help</h1><div class="shortcuts"><h2>Keyboard Shortcuts</h2><dl><dt><kbd>?</kbd></dt><dd>Show this help dialog</dd><dt><kbd>S</kbd></dt><dd>Focus the search field</dd><dt><kbd>↑</kbd></dt><dd>Move up in search results</dd><dt><kbd>↓</kbd></dt><dd>Move down in search results</dd><dt><kbd>↹</kbd></dt><dd>Switch tab</dd><dt><kbd>&#9166;</kbd></dt><dd>Go to active search result</dd><dt><kbd>+</kbd></dt><dd>Expand all sections</dd><dt><kbd>-</kbd></dt><dd>Collapse all sections</dd></dl></div><div class="infos"><h2>Search Tricks</h2><p>Prefix searches with a type followed by a colon (e.g. <code>fn:</code>) to restrict the search to a given type.</p><p>Accepted types are: <code>fn</code>, <code>mod</code>, <code>struct</code>, <code>enum</code>, <code>trait</code>, <code>type</code>, <code>macro</code>, and <code>const</code>.</p><p>Search functions by type signature (e.g. <code>vec -> usize</code> or <code>* -> vec</code>)</p><p>Search multiple things at once by splitting your query with comma (e.g. <code>str,u8</code> or <code>String,struct:Vec,test</code>)</p></div></div></aside><script>window.rootPath = "../";window.currentCrate = "proc_macro2";</script><script src="../aliases.js"></script><script src="../main.js"></script><script defer src="../search-index.js"></script></body></html>