<!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="The `Error` trait allows `Deserialize` implementations to create descriptive error messages belonging to the `Deserializer` against which they are currently running."><title>Error in serde::de - Rust</title><linkrel="preload"as="font"type="font/woff2"crossoriginhref="../../static.files/SourceSerif4-Regular-46f98efaafac5295.ttf.woff2"><linkrel="preload"as="font"type="font/woff2"crossoriginhref="../../static.files/FiraSans-Regular-018c141bf0843ffd.woff2"><linkrel="preload"as="font"type="font/woff2"crossoriginhref="../../static.files/FiraSans-Medium-8f9a781e4970d388.woff2"><linkrel="preload"as="font"type="font/woff2"crossoriginhref="../../static.files/SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2"><linkrel="preload"as="font"type="font/woff2"crossoriginhref="../../static.files/SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2"><linkrel="stylesheet"href="../../static.files/normalize-76eba96aa4d2e634.css"><linkrel="stylesheet"href="../../static.files/rustdoc-5bc39a1768837dd0.css"><metaname="rustdoc-vars"data-root-path="../../"data-static-root-path="../../static.files/"data-current-crate="serde"data-themes=""data-resource-suffix=""data-rustdoc-version="1.77.0 (aedd173a2 2024-03-17)"data-channel="1.77.0"data-search-js="search-dd67cee4cfa65049.js"data-settings-js="settings-4313503d2e1961c2.js"><scriptsrc="../../static.files/storage-4c98445ec4002617.js"></script><scriptdefersrc="sidebar-items.js"></script><scriptdefersrc="../../static.files/main-48f368f3872407c8.js"></script><noscript><linkrel="stylesheet"href="../../static.files/noscript-04d5337699b92874.css"></noscript><linkrel="alternate icon"type="image/png"href="../../static.files/favicon-16x16-8b506e7a72182f1c.png"><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 trait"><!--[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></nav><navclass="sidebar"><divclass="sidebar-crate"><h2><ahref="../../serde/index.html">serde</a><spanclass="version">1.0.197</span></h2></div><h2class="location"><ahref="#">Error</a></h2><divclass="sidebar-elems"><section><h3><ahref="#required-methods">Required Methods</a></h3><ulclass="block"><li><ahref="#tymethod.custom">custom</a></li></ul><h3><ahref="#provided-methods">Provided Methods</a></h3><ulclass="block"><li><ahref="#method.duplicate_field">duplicate_field</a></li><li><ahref="#method.invalid_length">invalid_length</a></li><li><ahref="#method.invalid_type">invalid_type</a></li><li><ahref="#method.invalid_value">invalid_value</a></li><li><ahref="#method.missing_field">missing_field</a></li><li><ahref="#method.unknown_field">unknown_field</a></li><li><ahref="#method.unknown_variant">unknown_variant</a></li></ul><h3><ahref="#object-safety">Object Safety</a></h3><h3><ahref="#implementors">Implementors</a></h3></section><h2><ahref="index.html">In serde::de</a></h2></div></nav><divclass="sidebar-resizer"></div>
<main><divclass="width-limiter"><navclass="sub"><formclass="search-form"><span></span><divid="sidebar-button"tabindex="-1"><ahref="../../serde/all.html"title="show sidebar"></a></div><inputclass="search-input"name="search"aria-label="Run search in the documentation"autocomplete="off"spellcheck="false"placeholder="Click or press ‘S’ to search, ‘?’ for more options…"type="search"><divid="help-button"tabindex="-1"><ahref="../../help.html"title="help">?</a></div><divid="settings-menu"tabindex="-1"><ahref="../../settings.html"title="settings"><imgwidth="22"height="22"alt="Change settings"src="../../static.files/wheel-7b819b6101059cd0.svg"></a></div></form></nav><sectionid="main-content"class="content"><divclass="main-heading"><h1>Trait <ahref="../index.html">serde</a>::<wbr><ahref="index.html">de</a>::<wbr><aclass="trait"href="#">Error</a><buttonid="copy-path"title="Copy item path to clipboard"><imgsrc="../../static.files/clipboard-7571035ce49a181d.svg"width="19"height="18"alt="Copy item path"></button></h1><spanclass="out-of-band"><aclass="src"href="../../src/serde/de/mod.rs.html#301">source</a> · <buttonid="toggle-all-docs"title="collapse all docs">[<span>−</span>]</button></span></div><preclass="rust item-decl"><code>pub trait Error: <aclass="trait"href="https://doc.rust-lang.org/1.77.0/core/marker/trait.Sized.html"title="trait core::marker::Sized">Sized</a> + <aclass="trait"href="https://doc.rust-lang.org/1.77.0/core/error/trait.Error.html"title="trait core::error::Error">StdError</a> {
T: <aclass="trait"href="https://doc.rust-lang.org/1.77.0/core/fmt/trait.Display.html"title="trait core::fmt::Display">Display</a>,</div></h4></section></summary><divclass="docblock"><p>Raised when there is general error when deserializing a type.</p>
</div></details></div><h2id="provided-methods"class="section-header">Provided Methods<ahref="#provided-methods"class="anchor">§</a></h2><divclass="methods"><detailsclass="toggle method-toggle"open><summary><sectionid="method.invalid_type"class="method"><aclass="src rightside"href="../../src/serde/de/mod.rs.html#301">source</a><h4class="code-header">fn <ahref="#method.invalid_type"class="fn">invalid_type</a>(unexp: <aclass="enum"href="enum.Unexpected.html"title="enum serde::de::Unexpected">Unexpected</a><'_>, exp: &dyn <aclass="trait"href="trait.Expected.html"title="trait serde::de::Expected">Expected</a>) -> Self</h4></section></summary><divclass="docblock"><p>Raised when a <code>Deserialize</code> receives a type different from what it was
expecting.</p>
<p>The <code>unexp</code> argument provides information about what type was received.
This is the type that was present in the input file or other source data
of the Deserializer.</p>
<p>The <code>exp</code> argument provides information about what type was being
expected. This is the type that is written in the program.</p>
<p>For example if we try to deserialize a String out of a JSON file
containing an integer, the unexpected type is the integer and the
expected type is the string.</p>
</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.invalid_value"class="method"><aclass="src rightside"href="../../src/serde/de/mod.rs.html#301">source</a><h4class="code-header">fn <ahref="#method.invalid_value"class="fn">invalid_value</a>(unexp: <aclass="enum"href="enum.Unexpected.html"title="enum serde::de::Unexpected">Unexpected</a><'_>, exp: &dyn <aclass="trait"href="trait.Expected.html"title="trait serde::de::Expected">Expected</a>) -> Self</h4></section></summary><divclass="docblock"><p>Raised when a <code>Deserialize</code> receives a value of the right type but that
is wrong for some other reason.</p>
<p>The <code>unexp</code> argument provides information about what value was received.
This is the value that was present in the input file or other source
data of the Deserializer.</p>
<p>The <code>exp</code> argument provides information about what value was being
expected. This is the type that is written in the program.</p>
<p>For example if we try to deserialize a String out of some binary data
that is not valid UTF-8, the unexpected value is the bytes and the
</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.invalid_length"class="method"><aclass="src rightside"href="../../src/serde/de/mod.rs.html#301">source</a><h4class="code-header">fn <ahref="#method.invalid_length"class="fn">invalid_length</a>(len: <aclass="primitive"href="https://doc.rust-lang.org/1.77.0/std/primitive.usize.html">usize</a>, exp: &dyn <aclass="trait"href="trait.Expected.html"title="trait serde::de::Expected">Expected</a>) -> Self</h4></section></summary><divclass="docblock"><p>Raised when deserializing a sequence or map and the input data contains
</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.unknown_variant"class="method"><aclass="src rightside"href="../../src/serde/de/mod.rs.html#301">source</a><h4class="code-header">fn <ahref="#method.unknown_variant"class="fn">unknown_variant</a>(variant: &<aclass="primitive"href="https://doc.rust-lang.org/1.77.0/std/primitive.str.html">str</a>, expected: &'static [&'static <aclass="primitive"href="https://doc.rust-lang.org/1.77.0/std/primitive.str.html">str</a>]) -> Self</h4></section></summary><divclass="docblock"><p>Raised when a <code>Deserialize</code> enum type received a variant with an
</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.unknown_field"class="method"><aclass="src rightside"href="../../src/serde/de/mod.rs.html#301">source</a><h4class="code-header">fn <ahref="#method.unknown_field"class="fn">unknown_field</a>(field: &<aclass="primitive"href="https://doc.rust-lang.org/1.77.0/std/primitive.str.html">str</a>, expected: &'static [&'static <aclass="primitive"href="https://doc.rust-lang.org/1.77.0/std/primitive.str.html">str</a>]) -> Self</h4></section></summary><divclass="docblock"><p>Raised when a <code>Deserialize</code> struct type received a field with an
</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.missing_field"class="method"><aclass="src rightside"href="../../src/serde/de/mod.rs.html#301">source</a><h4class="code-header">fn <ahref="#method.missing_field"class="fn">missing_field</a>(field: &'static <aclass="primitive"href="https://doc.rust-lang.org/1.77.0/std/primitive.str.html">str</a>) -> Self</h4></section></summary><divclass="docblock"><p>Raised when a <code>Deserialize</code> struct type expected to receive a required
</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.duplicate_field"class="method"><aclass="src rightside"href="../../src/serde/de/mod.rs.html#301">source</a><h4class="code-header">fn <ahref="#method.duplicate_field"class="fn">duplicate_field</a>(field: &'static <aclass="primitive"href="https://doc.rust-lang.org/1.77.0/std/primitive.str.html">str</a>) -> Self</h4></section></summary><divclass="docblock"><p>Raised when a <code>Deserialize</code> struct type received more than one of the
