<!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 `Arguments` struct in crate `core`."><meta name="keywords" content="rust, rustlang, rust-lang, Arguments"><title>core::fmt::Arguments - Rust</title><link rel="stylesheet" type="text/css" href="../../normalize1.35.0.css"><link rel="stylesheet" type="text/css" href="../../rustdoc1.35.0.css" id="mainThemeStyle"><link rel="stylesheet" type="text/css" href="../../dark1.35.0.css"><link rel="stylesheet" type="text/css" href="../../light1.35.0.css" id="themeStyle"><script src="../../storage1.35.0.js"></script><noscript><link rel="stylesheet" href="../../noscript1.35.0.css"></noscript><link rel="shortcut icon" href="../../favicon1.35.0.ico"><style type="text/css">#crate-search{background-image:url("../../down-arrow1.35.0.svg");}</style></head><body class="rustdoc struct"><!--[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='../../core/index.html'><img src='../../rust-logo1.35.0.png' alt='logo' width='100'></a><p class='location'>Struct Arguments</p><div class="sidebar-elems"><div class="block items"><a class="sidebar-title" href="#implementations">Trait Implementations</a><div class="sidebar-links"><a href="#impl-Clone">Clone</a><a href="#impl-Copy">Copy</a><a href="#impl-Debug">Debug</a><a href="#impl-Display">Display</a></div><a class="sidebar-title" href="#synthetic-implementations">Auto Trait Implementations</a><div class="sidebar-links"><a href="#impl-Send">!Send</a><a href="#impl-Sync">!Sync</a></div><a class="sidebar-title" href="#blanket-implementations">Blanket Implementations</a><div class="sidebar-links"><a href="#impl-Any">Any</a><a href="#impl-Borrow">Borrow</a><a href="#impl-BorrowMut">BorrowMut</a><a href="#impl-From">From</a><a href="#impl-Into">Into</a><a href="#impl-TryFrom">TryFrom</a><a href="#impl-TryInto">TryInto</a></div></div><p class='location'><a href='../index.html'>core</a>::<wbr><a href='index.html'>fmt</a></p><script>window.sidebarCurrent = {name: 'Arguments', ty: 'struct', 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="../../brush1.35.0.svg" width="18" alt="Pick another theme!"></button><div id="theme-choices"></div></div><script src="../../theme1.35.0.js"></script><nav class="sub"><form class="search-form js-only"><div class="search-container"><div><select id="crate-search"><option value="All crates">All crates</option></select><input class="search-input" name="search" 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="../../wheel1.35.0.svg" width="18" alt="Change settings"></a></div></form></nav><section id="main" class="content"><h1 class='fqn'><span class='out-of-band'><span class='since' title='Stable since Rust version 1.0.0'>1.0.0</span><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/core/fmt/mod.rs.html#395-405' title='goto source code'>[src]</a></span><span class='in-band'>Struct <a href='../index.html'>core</a>::<wbr><a href='index.html'>fmt</a>::<wbr><a class="struct" href=''>Arguments</a></span></h1><div class="docblock type-decl hidden-by-usual-hider"><pre class='rust struct'>pub struct Arguments<'a> { /* fields omitted */ }</pre></div><div class='docblock'><p>This structure represents a safely precompiled version of a format string
and its arguments. This cannot be generated at runtime because it cannot
safely be done, so no constructors are given and the fields are private
to prevent modification.</p>
<p>The <a href="../../std/macro.format_args.html"><code>format_args!</code></a> macro will safely create an instance of this structure.
The macro validates the format string at compile-time so usage of the
<a href="../../std/fmt/fn.write.html"><code>write</code></a> and <a href="../../std/fmt/fn.format.html"><code>format</code></a> functions can be safely performed.</p>
<p>You can use the <code>Arguments<'a></code> that <a href="../../std/macro.format_args.html"><code>format_args!</code></a> returns in <code>Debug</code>
and <code>Display</code> contexts as seen below. The example also shows that <code>Debug</code>
and <code>Display</code> format to the same thing: the interpolated format string
in <code>format_args!</code>.</p>
<div class="example-wrap"><pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">debug</span> <span class="op">=</span> <span class="macro">format</span><span class="macro">!</span>(<span class="string">"{:?}"</span>, <span class="macro">format_args</span><span class="macro">!</span>(<span class="string">"{} foo {:?}"</span>, <span class="number">1</span>, <span class="number">2</span>));
<span class="kw">let</span> <span class="ident">display</span> <span class="op">=</span> <span class="macro">format</span><span class="macro">!</span>(<span class="string">"{}"</span>, <span class="macro">format_args</span><span class="macro">!</span>(<span class="string">"{} foo {:?}"</span>, <span class="number">1</span>, <span class="number">2</span>));
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="string">"1 foo 2"</span>, <span class="ident">display</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">display</span>, <span class="ident">debug</span>);<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=%23!%5Ballow(unused)%5D%0Afn%20main()%20%7B%0Alet%20debug%20%3D%20format!(%22%7B%3A%3F%7D%22%2C%20format_args!(%22%7B%7D%20foo%20%7B%3A%3F%7D%22%2C%201%2C%202))%3B%0Alet%20display%20%3D%20format!(%22%7B%7D%22%2C%20format_args!(%22%7B%7D%20foo%20%7B%3A%3F%7D%22%2C%201%2C%202))%3B%0Aassert_eq!(%221%20foo%202%22%2C%20display)%3B%0Aassert_eq!(display%2C%20debug)%3B%0A%7D">Run</a></pre></div>
</div><h2 id='implementations' class='small-section-header'>Trait Implementations<a href='#implementations' class='anchor'></a></h2><div id='implementations-list'><h3 id='impl-Copy' class='impl'><code class='in-band'>impl<'a> <a class="trait" href="../../core/marker/trait.Copy.html" title="trait core::marker::Copy">Copy</a> for <a class="struct" href="../../core/fmt/struct.Arguments.html" title="struct core::fmt::Arguments">Arguments</a><'a></code><a href='#impl-Copy' class='anchor'></a><a class='srclink' href='../../src/core/fmt/mod.rs.html#394' title='goto source code'>[src]</a></h3><div class='impl-items'></div><h3 id='impl-Clone' class='impl'><code class='in-band'>impl<'a> <a class="trait" href="../../core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a> for <a class="struct" href="../../core/fmt/struct.Arguments.html" title="struct core::fmt::Arguments">Arguments</a><'a></code><a href='#impl-Clone' class='anchor'></a><a class='srclink' href='../../src/core/fmt/mod.rs.html#394' title='goto source code'>[src]</a></h3><div class='impl-items'><h4 id='method.clone' class="method hidden"><code id='clone.v'>fn <a href='../../core/clone/trait.Clone.html#tymethod.clone' class='fnname'>clone</a>(&self) -> <a class="struct" href="../../core/fmt/struct.Arguments.html" title="struct core::fmt::Arguments">Arguments</a><'a></code><a class='srclink' href='../../src/core/fmt/mod.rs.html#394' title='goto source code'>[src]</a></h4><div class='docblock hidden'><p>Returns a copy of the value. <a href="../../core/clone/trait.Clone.html#tymethod.clone">Read more</a></p>
</div><h4 id='method.clone_from' class="method"><code id='clone_from.v'>fn <a href='../../core/clone/trait.Clone.html#method.clone_from' class='fnname'>clone_from</a>(&mut self, source: &Self)</code><a class='srclink' href='../../src/core/clone.rs.html#131-133' title='goto source code'>[src]</a></h4><div class='docblock'><p>Performs copy-assignment from <code>source</code>. <a href="../../core/clone/trait.Clone.html#method.clone_from">Read more</a></p>
</div></div><h3 id='impl-Debug' class='impl'><code class='in-band'>impl<'_> <a class="trait" href="../../core/fmt/trait.Debug.html" title="trait core::fmt::Debug">Debug</a> for <a class="struct" href="../../core/fmt/struct.Arguments.html" title="struct core::fmt::Arguments">Arguments</a><'_></code><a href='#impl-Debug' class='anchor'></a><a class='srclink' href='../../src/core/fmt/mod.rs.html#408-412' title='goto source code'>[src]</a></h3><div class='impl-items'><h4 id='method.fmt' class="method hidden"><code id='fmt.v'>fn <a href='../../core/fmt/trait.Debug.html#tymethod.fmt' class='fnname'>fmt</a>(&self, fmt: &mut <a class="struct" href="../../core/fmt/struct.Formatter.html" title="struct core::fmt::Formatter">Formatter</a>) -> <a class="type" href="../../core/fmt/type.Result.html" title="type core::fmt::Result">Result</a></code><a class='srclink' href='../../src/core/fmt/mod.rs.html#409-411' title='goto source code'>[src]</a></h4><div class='docblock hidden'><p>Formats the value using the given formatter. <a href="../../core/fmt/trait.Debug.html#tymethod.fmt">Read more</a></p>
</div></div><h3 id='impl-Display' class='impl'><code class='in-band'>impl<'_> <a class="trait" href="../../core/fmt/trait.Display.html" title="trait core::fmt::Display">Display</a> for <a class="struct" href="../../core/fmt/struct.Arguments.html" title="struct core::fmt::Arguments">Arguments</a><'_></code><a href='#impl-Display' class='anchor'></a><a class='srclink' href='../../src/core/fmt/mod.rs.html#415-419' title='goto source code'>[src]</a></h3><div class='impl-items'><h4 id='method.fmt-1' class="method hidden"><code id='fmt.v-1'>fn <a href='../../core/fmt/trait.Display.html#tymethod.fmt' class='fnname'>fmt</a>(&self, fmt: &mut <a class="struct" href="../../core/fmt/struct.Formatter.html" title="struct core::fmt::Formatter">Formatter</a>) -> <a class="type" href="../../core/fmt/type.Result.html" title="type core::fmt::Result">Result</a></code><a class='srclink' href='../../src/core/fmt/mod.rs.html#416-418' title='goto source code'>[src]</a></h4><div class='docblock hidden'><p>Formats the value using the given formatter. <a href="../../core/fmt/trait.Display.html#tymethod.fmt">Read more</a></p>
</div></div></div><h2 id='synthetic-implementations' class='small-section-header'>Auto Trait Implementations<a href='#synthetic-implementations' class='anchor'></a></h2><div id='synthetic-implementations-list'><h3 id='impl-Send' class='impl'><code class='in-band'>impl<'a> !<a class="trait" href="../../core/marker/trait.Send.html" title="trait core::marker::Send">Send</a> for <a class="struct" href="../../core/fmt/struct.Arguments.html" title="struct core::fmt::Arguments">Arguments</a><'a></code><a href='#impl-Send' class='anchor'></a></h3><div class='impl-items'></div><h3 id='impl-Sync' class='impl'><code class='in-band'>impl<'a> !<a class="trait" href="../../core/marker/trait.Sync.html" title="trait core::marker::Sync">Sync</a> for <a class="struct" href="../../core/fmt/struct.Arguments.html" title="struct core::fmt::Arguments">Arguments</a><'a></code><a href='#impl-Sync' class='anchor'></a></h3><div class='impl-items'></div></div><h2 id='blanket-implementations' class='small-section-header'>Blanket Implementations<a href='#blanket-implementations' class='anchor'></a></h2><div id='blanket-implementations-list'><h3 id='impl-Into' class='impl'><code class='in-band'>impl<T, U> <a class="trait" href="../../core/convert/trait.Into.html" title="trait core::convert::Into">Into</a> for T <span class="where fmt-newline">where<br> U: <a class="trait" href="../../core/convert/trait.From.html" title="trait core::convert::From">From</a><T>, </span></code><a href='#impl-Into' class='anchor'></a><a class='srclink' href='../../src/core/convert.rs.html#537-542' title='goto source code'>[src]</a></h3><div class='impl-items'><h4 id='method.into' class="method hidden"><code id='into.v'>fn <a href='../../core/convert/trait.Into.html#tymethod.into' class='fnname'>into</a>(Self) -> U</code><a class='srclink' href='../../src/core/convert.rs.html#539-541' title='goto source code'>[src]</a></h4><div class='docblock hidden'><p>Performs the conversion.</p>
</div></div><h3 id='impl-From' class='impl'><code class='in-band'>impl<T> <a class="trait" href="../../core/convert/trait.From.html" title="trait core::convert::From">From</a> for T</code><a href='#impl-From' class='anchor'></a><a class='srclink' href='../../src/core/convert.rs.html#546-548' title='goto source code'>[src]</a></h3><div class='impl-items'><h4 id='method.from' class="method hidden"><code id='from.v'>fn <a href='../../core/convert/trait.From.html#tymethod.from' class='fnname'>from</a>(T) -> T</code><a class='srclink' href='../../src/core/convert.rs.html#547' title='goto source code'>[src]</a></h4><div class='docblock hidden'><p>Performs the conversion.</p>
</div></div><h3 id='impl-TryInto' class='impl'><code class='in-band'>impl<T, U> <a class="trait" href="../../core/convert/trait.TryInto.html" title="trait core::convert::TryInto">TryInto</a> for T <span class="where fmt-newline">where<br> U: <a class="trait" href="../../core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><T>, </span></code><a href='#impl-TryInto' class='anchor'></a><a class='srclink' href='../../src/core/convert.rs.html#553-560' title='goto source code'>[src]</a></h3><div class='impl-items'><h4 id='associatedtype.Error' class="type"><code id='Error.t'>type <a href='../../core/convert/trait.TryInto.html#associatedtype.Error' class="type">Error</a> = <U as <a class="trait" href="../../core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><T>>::<a class="type" href="../../core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a></code></h4><div class='docblock'><p>The type returned in the event of a conversion error.</p>
</div><h4 id='method.try_into' class="method hidden"><code id='try_into.v'>fn <a href='../../core/convert/trait.TryInto.html#tymethod.try_into' class='fnname'>try_into</a>(Self) -> <a class="enum" href="../../core/result/enum.Result.html" title="enum core::result::Result">Result</a><U, <U as <a class="trait" href="../../core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><T>>::<a class="type" href="../../core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a>></code><a class='srclink' href='../../src/core/convert.rs.html#557-559' title='goto source code'>[src]</a></h4><div class='docblock hidden'><p>Performs the conversion.</p>
</div></div><h3 id='impl-TryFrom' class='impl'><code class='in-band'>impl<T, U> <a class="trait" href="../../core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a> for T <span class="where fmt-newline">where<br> U: <a class="trait" href="../../core/convert/trait.Into.html" title="trait core::convert::Into">Into</a><T>, </span></code><a href='#impl-TryFrom' class='anchor'></a><a class='srclink' href='../../src/core/convert.rs.html#565-571' title='goto source code'>[src]</a></h3><div class='impl-items'><h4 id='associatedtype.Error-1' class="type"><code id='Error.t-1'>type <a href='../../core/convert/trait.TryFrom.html#associatedtype.Error' class="type">Error</a> = <a class="enum" href="../../core/convert/enum.Infallible.html" title="enum core::convert::Infallible">Infallible</a></code></h4><div class='docblock'><p>The type returned in the event of a conversion error.</p>
</div><h4 id='method.try_from' class="method hidden"><code id='try_from.v'>fn <a href='../../core/convert/trait.TryFrom.html#tymethod.try_from' class='fnname'>try_from</a>(U) -> <a class="enum" href="../../core/result/enum.Result.html" title="enum core::result::Result">Result</a><T, <T as <a class="trait" href="../../core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><U>>::<a class="type" href="../../core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a>></code><a class='srclink' href='../../src/core/convert.rs.html#568-570' title='goto source code'>[src]</a></h4><div class='docblock hidden'><p>Performs the conversion.</p>
</div></div><h3 id='impl-Borrow' class='impl'><code class='in-band'>impl<T> <a class="trait" href="../../core/borrow/trait.Borrow.html" title="trait core::borrow::Borrow">Borrow</a> for T <span class="where fmt-newline">where<br> T: ?<a class="trait" href="../../core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>, </span></code><a href='#impl-Borrow' class='anchor'></a><a class='srclink' href='../../src/core/borrow.rs.html#213-215' title='goto source code'>[src]</a></h3><div class='impl-items'><h4 id='method.borrow' class="method hidden"><code id='borrow.v'>fn <a href='../../core/borrow/trait.Borrow.html#tymethod.borrow' class='fnname'>borrow</a>(&Self) -> &T</code><a class='srclink' href='../../src/core/borrow.rs.html#214' title='goto source code'>[src]</a></h4><div class='docblock hidden'><p>Immutably borrows from an owned value. <a href="../../core/borrow/trait.Borrow.html#tymethod.borrow">Read more</a></p>
</div></div><h3 id='impl-BorrowMut' class='impl'><code class='in-band'>impl<T> <a class="trait" href="../../core/borrow/trait.BorrowMut.html" title="trait core::borrow::BorrowMut">BorrowMut</a> for T <span class="where fmt-newline">where<br> T: ?<a class="trait" href="../../core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>, </span></code><a href='#impl-BorrowMut' class='anchor'></a><a class='srclink' href='../../src/core/borrow.rs.html#218-220' title='goto source code'>[src]</a></h3><div class='impl-items'><h4 id='method.borrow_mut' class="method hidden"><code id='borrow_mut.v'>fn <a href='../../core/borrow/trait.BorrowMut.html#tymethod.borrow_mut' class='fnname'>borrow_mut</a>(&mut Self) -> &mut T</code><a class='srclink' href='../../src/core/borrow.rs.html#219' title='goto source code'>[src]</a></h4><div class='docblock hidden'><p>Mutably borrows from an owned value. <a href="../../core/borrow/trait.BorrowMut.html#tymethod.borrow_mut">Read more</a></p>
</div></div><h3 id='impl-Any' class='impl'><code class='in-band'>impl<T> <a class="trait" href="../../core/any/trait.Any.html" title="trait core::any::Any">Any</a> for T <span class="where fmt-newline">where<br> T: 'static + ?<a class="trait" href="../../core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>, </span></code><a href='#impl-Any' class='anchor'></a><a class='srclink' href='../../src/core/any.rs.html#100-102' title='goto source code'>[src]</a></h3><div class='impl-items'><h4 id='method.type_id' class="method hidden"><code id='type_id.v'>fn <a href='../../core/any/trait.Any.html#tymethod.type_id' class='fnname'>type_id</a>(&Self) -> <a class="struct" href="../../core/any/struct.TypeId.html" title="struct core::any::TypeId">TypeId</a></code><a class='srclink' href='../../src/core/any.rs.html#101' title='goto source code'>[src]</a></h4><div class='docblock hidden'><p>Gets the <code>TypeId</code> of <code>self</code>. <a href="../../core/any/trait.Any.html#tymethod.type_id">Read more</a></p>
</div></div></div></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>⏎</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 = "core";</script><script src="../../aliases.js"></script><script src="../../main1.35.0.js"></script><script defer src="../../search-index.js"></script></body></html>
distrib
>
Mageia
>
7
>
armv7hl
>
media
>
core-release
>
by-pkgid
>
0c2243f8a1696816431e7210e991fa52
>
files
>
11120
