<!DOCTYPE html><htmllang="en"><head><metacharset="utf-8"><metaname="viewport"content="width=device-width, initial-scale=1.0"><metaname="generator"content="rustdoc"><metaname="description"content="Behavior of arguments when they are encountered while parsing"><title>ArgAction in clap - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-46f98efaafac5295.ttf.woff2,FiraSans-Regular-018c141bf0843ffd.woff2,FiraSans-Medium-8f9a781e4970d388.woff2,SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2,SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/${f}">`).join(""))</script><linkrel="stylesheet"href="../static.files/normalize-76eba96aa4d2e634.css"><linkrel="stylesheet"href="../static.files/rustdoc-dd39b87e5fcfba68.css"><metaname="rustdoc-vars"data-root-path="../"data-static-root-path="../static.files/"data-current-crate="clap"data-themes=""data-resource-suffix=""data-rustdoc-version="1.80.0 (051478957 2024-07-21)"data-channel="1.80.0"data-search-js="search-d52510db62a78183.js"data-settings-js="settings-4313503d2e1961c2.js"><scriptsrc="../static.files/storage-118b08c4c78b968e.js"></script><scriptdefersrc="sidebar-items.js"></script><scriptdefersrc="../static.files/main-20a3ad099b048cf2.js"></script><noscript><linkrel="stylesheet"href="../static.files/noscript-df360f571f6edeae.css"></noscript><linkrel="alternate icon"type="image/png"href="../static.files/favicon-32x32-422f7d1d52889060.png"><linkrel="icon"type="image/svg+xml"href="../static.files/favicon-2c020d218678b618.svg"></head><bodyclass="rustdoc enum"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><navclass="mobile-topbar"><buttonclass="sidebar-menu-toggle"title="show sidebar"></button><aclass="logo-container"href="../clap/index.html"><imgsrc="https://raw.githubusercontent.com/clap-rs/clap/master/assets/clap.png"alt=""></a></nav><navclass="sidebar"><divclass="sidebar-crate"><aclass="logo-container"href="../clap/index.html"><imgsrc="https://raw.githubusercontent.com/clap-rs/clap/master/assets/clap.png"alt="logo"></a><h2><ahref="../clap/index.html">clap</a><spanclass="version">4.5.11</span></h2></div><h2class="location"><ahref="#">ArgAction</a></h2><divclass="sidebar-elems"><section><h3><ahref="#variants">Variants</a></h3><ulclass="block variant"><li><ahref="#variant.Append">Append</a></li><li><ahref="#variant.Count">Count</a></li><li><ahref="#variant.Help">Help</a></li><li><ahref="#variant.HelpLong">HelpLong</a></li><li><ahref="#variant.HelpShort">HelpShort</a></li><li><ahref="#variant.Set">Set</a></li><li><ahref="#variant.SetFalse">SetFalse</a></li><li><ahref="#variant.SetTrue">SetTrue</a></li><li><ahref="#variant.Version">Version</a></li></ul><h3><ahref="#implementations">Methods</a></h3><ulclass="block method"><li><ahref="#method.takes_values">takes_values</a></li></ul><h3><ahref="#trait-implementations">Trait Implementations</a></h3><ulclass="block trait-implementation"><li><ahref="#impl-Clone-for-ArgAction">Clone</a></li><li><ahref="#impl-Debug-for-ArgAction">Debug</a></li><li><ahref="#impl-IntoResettable%3CArgAction%3E-for-ArgAction">IntoResettable<ArgAction></a></li><li><ahref="#impl-IntoResettable%3CArgAction%3E-for-Option%3CArgAction%3E">IntoResettable<ArgAction></a></li></ul><h3><ahref="#synthetic-implementations">Auto Trait Implementations</a></h3><ulclass="block synthetic-implementation"><li><ahref="#impl-Freeze-for-ArgAction">Freeze</a></li><li><ahref="#impl-RefUnwindSafe-for-ArgAction">RefUnwindSafe</a></li><li><ahref="#impl-Send-for-ArgAction">Send</a></li><li><ahref="#impl-Sync-for-ArgAction">Sync</a></li><li><ahref="#impl-Unpin-for-ArgAction">Unpin</a></li><li><ahref="#impl-UnwindSafe-for-ArgAction">UnwindSafe</a></li></ul><h3><ahref="#blanket-implementations">Blanket Implementations</a></h3><ulclass="blockbla
}</code></pre><detailsclass="toggle top-doc"open><summaryclass="hideme"><span>Expand description</span></summary><divclass="docblock"><p>Behavior of arguments when they are encountered while parsing</p>
</div></details><h2id="variants"class="variants section-header">Variants (Non-exhaustive)<ahref="#variants"class="anchor">§</a></h2><detailsclass="toggle non-exhaustive"><summaryclass="hideme"><span>This enum is marked as non-exhaustive</span></summary><divclass="docblock">Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.</div></details><divclass="variants"><sectionid="variant.Set"class="variant"><ahref="#variant.Set"class="anchor">§</a><h3class="code-header">Set</h3></section><divclass="docblock"><p>When encountered, store the associated value(s) in <ahref="struct.ArgMatches.html"title="struct clap::ArgMatches"><code>ArgMatches</code></a></p>
<p><strong>NOTE:</strong> If the argument has previously been seen, it will result in a
<ahref="struct.Command.html#method.args_override_self"title="method clap::Command::args_override_self"><code>Command::args_override_self(true)</code></a> is set.</p>
</div><sectionid="variant.Append"class="variant"><ahref="#variant.Append"class="anchor">§</a><h3class="code-header">Append</h3></section><divclass="docblock"><p>When encountered, store the associated value(s) in <ahref="struct.ArgMatches.html"title="struct clap::ArgMatches"><code>ArgMatches</code></a></p>
</div><sectionid="variant.SetTrue"class="variant"><ahref="#variant.SetTrue"class="anchor">§</a><h3class="code-header">SetTrue</h3></section><divclass="docblock"><p>When encountered, act as if <code>"true"</code> was encountered on the command-line</p>
<p>If no <ahref="struct.Arg.html#method.default_value"title="method clap::Arg::default_value"><code>default_value</code></a> is set, it will be <code>false</code>.</p>
<p>No value is allowed. To optionally accept a value, see
<ahref="struct.Command.html#method.args_override_self"title="method clap::Command::args_override_self"><code>Command::args_override_self(true)</code></a> is set.</p>
<p>You can use <ahref="builder/trait.TypedValueParser.html#method.map"title="method clap::builder::TypedValueParser::map"><code>TypedValueParser::map</code></a> to have the
</div><sectionid="variant.SetFalse"class="variant"><ahref="#variant.SetFalse"class="anchor">§</a><h3class="code-header">SetFalse</h3></section><divclass="docblock"><p>When encountered, act as if <code>"false"</code> was encountered on the command-line</p>
<p>If no <ahref="struct.Arg.html#method.default_value"title="method clap::Arg::default_value"><code>default_value</code></a> is set, it will be <code>true</code>.</p>
<p>No value is allowed. To optionally accept a value, see
<ahref="struct.Command.html#method.args_override_self"title="method clap::Command::args_override_self"><code>Command::args_override_self(true)</code></a> is set.</p>
</div><sectionid="variant.Count"class="variant"><ahref="#variant.Count"class="anchor">§</a><h3class="code-header">Count</h3></section><divclass="docblock"><p>When encountered, increment a <code>u8</code> counter starting from <code>0</code>.</p>
<p>If no <ahref="struct.Arg.html#method.default_value"title="method clap::Arg::default_value"><code>default_value</code></a> is set, it will be <code>0</code>.</p>
<p>No value is allowed. To optionally accept a value, see
<p>Depending on the flag, <ahref="struct.Command.html#method.print_long_help"title="method clap::Command::print_long_help"><code>Command::print_long_help</code></a> may be shown</p>
<p>Depending on the flag, <ahref="struct.Command.html#method.long_version"title="method clap::Command::long_version"><code>Command::long_version</code></a> may be shown</p>
<p><ahref="struct.Arg.html#method.default_values"title="method clap::Arg::default_values"><code>default_values</code></a> and [<code>env</code>][super::Arg::env] may still be
<code><ahref="https://doc.rust-lang.org/1.80.0/core/convert/trait.From.html"title="trait core::convert::From">From</a><T> for U</code> chooses to do.</p>
</div></details></div></details><detailsclass="toggle implementors-toggle"><summary><sectionid="impl-ToOwned-for-T"class="impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.80.0/src/alloc/borrow.rs.html#83-85">source</a><ahref="#impl-ToOwned-for-T"class="anchor">§</a><h3class="code-header">impl<T><aclass="trait"href="https://doc.rust-lang.org/1.80.0/alloc/borrow/trait.ToOwned.html"title="trait alloc::borrow::ToOwned">ToOwned</a> for T<divclass="where">where
T: <aclass="trait"href="https://doc.rust-lang.org/1.80.0/core/clone/trait.Clone.html"title="trait core::clone::Clone">Clone</a>,</div></h3></section></summary><divclass="impl-items"><detailsclass="toggle"open><summary><sectionid="associatedtype.Owned"class="associatedtype trait-impl"><ahref="#associatedtype.Owned"class="anchor">§</a><h4class="code-header">type <ahref="https://doc.rust-lang.org/1.80.0/alloc/borrow/trait.ToOwned.html#associatedtype.Owned"class="associatedtype">Owned</a> = T</h4></section></summary><divclass='docblock'>The resulting type after obtaining ownership.</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.to_owned"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.80.0/src/alloc/borrow.rs.html#88">source</a><ahref="#method.to_owned"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.80.0/alloc/borrow/trait.ToOwned.html#tymethod.to_owned"class="fn">to_owned</a>(&self) -> T</h4></section></summary><divclass='docblock'>Creates owned data from borrowed data, usually by cloning. <ahref="https://doc.rust-lang.org/1.80.0/alloc/borrow/trait.ToOwned.html#tymethod.to_owned">Read more</a></div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.clone_into"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.80.0/src/alloc/borrow.rs.html#92">source</a><ahref="#method.clone_into"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.80.0/alloc/borrow/trait.ToOwned.html#method.clone_into"class="fn">clone_into</a>(&self, target: <aclass="primitive"href="https://doc.rust-lang.org/1.80.0/std/primitive.reference.html">&mut T</a>)</h4></section></summary><divclass='docblock'>Uses borrowed data to replace owned data, usually by cloning. <ahref="https://doc.rust-lang.org/1.80.0/alloc/borrow/trait.ToOwned.html#method.clone_into">Read more</a></div></details></div></details><detailsclass="toggle implementors-toggle"><summary><sectionid="impl-TryFrom%3CU%3E-for-T"class="impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.80.0/src/core/convert/mod.rs.html#805-807">source</a><ahref="#impl-TryFrom%3CU%3E-for-T"class="anchor">§</a><h3class="code-header">impl<T, U><aclass="trait"href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><U> for T<divclass="where">where
U: <aclass="trait"href="https://doc.rust-lang.org/1.80.0/core/convert/trait.Into.html"title="trait core::convert::Into">Into</a><T>,</div></h3></section></summary><divclass="impl-items"><detailsclass="toggle"open><summary><sectionid="associatedtype.Error"class="associatedtype trait-impl"><ahref="#associatedtype.Error"class="anchor">§</a><h4class="code-header">type <ahref="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html#associatedtype.Error"class="associatedtype">Error</a> = <aclass="enum"href="https://doc.rust-lang.org/1.80.0/core/convert/enum.Infallible.html"title="enum core::convert::Infallible">Infallible</a></h4></section></summary><divclass='docblock'>The type returned in the event of a conversion error.</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.try_from"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.80.0/src/core/convert/mod.rs.html#812">source</a><ahref="#method.try_from"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html#tymethod.try_from"class="fn">try_from</a>(value: U) -><aclass="enum"href="https://doc.rust-lang.org/1.80.0/core/result/enum.Result.html"title="enum core::result::Result">Result</a><T, <T as <aclass="trait"href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><U>>::<aclass="associatedtype"href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html#associatedtype.Error"title="type core::convert::TryFrom::Error">Error</a>></h4></section></summary><divclass='docblock'>Performs the conversion.</div></details></div></details><detailsclass="toggle implementors-toggle"><summary><sectionid="impl-TryInto%3CU%3E-for-T"class="impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.80.0/src/core/convert/mod.rs.html#790-792">source</a><ahref="#impl-TryInto%3CU%3E-for-T"class="anchor">§</a><h3class="code-header">impl<T, U><aclass="trait"href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryInto.html"title="trait core::convert::TryInto">TryInto</a><U> for T<divclass="where">where
U: <aclass="trait"href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><T>,</div></h3></section></summary><divclass="impl-items"><detailsclass="toggle"open><summary><sectionid="associatedtype.Error-1"class="associatedtype trait-impl"><ahref="#associatedtype.Error-1"class="anchor">§</a><h4class="code-header">type <ahref="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryInto.html#associatedtype.Error"class="associatedtype">Error</a> = <U as <aclass="trait"href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><T>>::<aclass="associatedtype"href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html#associatedtype.Error"title="type core::convert::TryFrom::Error">Error</a></h4></section></summary><divclass='docblock'>The type returned in the event of a conversion error.</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.try_into"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.80.0/src/core/convert/mod.rs.html#797">source</a><ahref="#method.try_into"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryInto.html#tymethod.try_into"class="fn">try_into</a>(self) -><aclass="enum"href="https://doc.rust-lang.org/1.80.0/core/result/enum.Result.html"title="enum core::result::Result">Result</a><U, <U as <aclass="trait"href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><T>>::<aclass="associatedtype"href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html#associatedtype.Error"title="type core::convert::TryFrom::Error">Error</a>></h4></section></summary><divclass='docblock'>Performs the conversion.</div></details></div></details></div></section></div></main></body></html>
