| <!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="The `Error` trait allows `Deserialize` implementations to create descriptive error messages belonging to the `Deserializer` against which they are currently running."><meta name="keywords" content="rust, rustlang, rust-lang, Error"><title>Error in serde::de - Rust</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><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="../../ayu.css" disabled><link rel="stylesheet" type="text/css" href="../../dark.css" disabled><link rel="stylesheet" type="text/css" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script src="../../crates.js"></script><script defer src="../../main.js"></script> |
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| </a><h2 class="location">Trait Error</h2><div class="sidebar-elems"><div class="block items"><h3 class="sidebar-title"><a href="#required-methods">Required Methods</a></h3><div class="sidebar-links"><a href="#tymethod.custom">custom</a></div><h3 class="sidebar-title"><a href="#provided-methods">Provided Methods</a></h3><div class="sidebar-links"><a href="#method.duplicate_field">duplicate_field</a><a href="#method.invalid_length">invalid_length</a><a href="#method.invalid_type">invalid_type</a><a href="#method.invalid_value">invalid_value</a><a href="#method.missing_field">missing_field</a><a href="#method.unknown_field">unknown_field</a><a href="#method.unknown_variant">unknown_variant</a></div><h3 class="sidebar-title"><a href="#implementors">Implementors</a></h3></div><h2 class="location">Other items in<br><a href="../index.html">serde</a>::<wbr><a href="index.html">de</a></h2><div id="sidebar-vars" data-name="Error" data-ty="trait" data-relpath=""></div><script defer src="sidebar-items.js"></script></div></nav><main><div class="width-limiter"><div class="sub-container"><a class="sub-logo-container" href="../../serde/index.html"><img class="rust-logo" src="../../rust-logo.png" alt="logo"></a><nav class="sub"><div class="theme-picker"><button id="theme-picker" aria-label="Pick another theme!" aria-haspopup="menu" title="themes"><img width="18" height="18" alt="Pick another theme!" src="../../brush.svg"></button><div id="theme-choices" role="menu"></div></div><form class="search-form"><div class="search-container"><div> |
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| <h1 class="fqn"><span class="in-band">Trait <a href="../index.html">serde</a>::<wbr><a href="index.html">de</a>::<wbr><a class="trait" href="#">Error</a><button id="copy-path" onclick="copy_path(this)" title="Copy item path to clipboard"><img src="../../clipboard.svg" width="19" height="18" alt="Copy item path"></button></span></h1><span class="out-of-band"> |
| <a class="srclink" href="../../src/serde/de/mod.rs.html#297" title="goto source code">source</a> · |
| <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class="inner">−</span>]</a></span></div> |
| <div class="docblock item-decl"><pre class="rust trait"><code>pub trait Error: <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a> + <a class="trait" href="https://doc.rust-lang.org/nightly/std/error/trait.Error.html" title="trait std::error::Error">StdError</a> { |
| fn <a href="#tymethod.custom" class="fnname">custom</a><T>(msg: T) -> Self<br> <span class="where">where<br> T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/fmt/trait.Display.html" title="trait core::fmt::Display">Display</a></span>; |
| |
| fn <a href="#method.invalid_type" class="fnname">invalid_type</a>(unexp: <a class="enum" href="enum.Unexpected.html" title="enum serde::de::Unexpected">Unexpected</a><'_>, exp: &dyn <a class="trait" href="trait.Expected.html" title="trait serde::de::Expected">Expected</a>) -> Self { ... } |
| <div class="item-spacer"></div> fn <a href="#method.invalid_value" class="fnname">invalid_value</a>(unexp: <a class="enum" href="enum.Unexpected.html" title="enum serde::de::Unexpected">Unexpected</a><'_>, exp: &dyn <a class="trait" href="trait.Expected.html" title="trait serde::de::Expected">Expected</a>) -> Self { ... } |
| <div class="item-spacer"></div> fn <a href="#method.invalid_length" class="fnname">invalid_length</a>(len: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.usize.html">usize</a>, exp: &dyn <a class="trait" href="trait.Expected.html" title="trait serde::de::Expected">Expected</a>) -> Self { ... } |
| <div class="item-spacer"></div> fn <a href="#method.unknown_variant" class="fnname">unknown_variant</a>(variant: &<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.str.html">str</a>, expected: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.slice.html">&'static [</a>&'static <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.str.html">str</a><a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.slice.html">]</a>) -> Self { ... } |
| <div class="item-spacer"></div> fn <a href="#method.unknown_field" class="fnname">unknown_field</a>(field: &<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.str.html">str</a>, expected: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.slice.html">&'static [</a>&'static <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.str.html">str</a><a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.slice.html">]</a>) -> Self { ... } |
| <div class="item-spacer"></div> fn <a href="#method.missing_field" class="fnname">missing_field</a>(field: &'static <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.str.html">str</a>) -> Self { ... } |
| <div class="item-spacer"></div> fn <a href="#method.duplicate_field" class="fnname">duplicate_field</a>(field: &'static <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.str.html">str</a>) -> Self { ... } |
| }</code></pre></div><details class="rustdoc-toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>The <code>Error</code> trait allows <code>Deserialize</code> implementations to create descriptive |
| error messages belonging to the <code>Deserializer</code> against which they are |
| currently running.</p> |
| <p>Every <code>Deserializer</code> declares an <code>Error</code> type that encompasses both |
| general-purpose deserialization errors as well as errors specific to the |
| particular deserialization format. For example the <code>Error</code> type of |
| <code>serde_json</code> can represent errors like an invalid JSON escape sequence or an |
| unterminated string literal, in addition to the error cases that are part of |
| this trait.</p> |
| <p>Most deserializers should only need to provide the <code>Error::custom</code> method |
| and inherit the default behavior for the other methods.</p> |
| <h2 id="example-implementation" class="section-header"><a href="#example-implementation">Example implementation</a></h2> |
| <p>The <a href="https://serde.rs/data-format.html">example data format</a> presented on the website shows an error |
| type appropriate for a basic JSON data format.</p> |
| </div></details><h2 id="required-methods" class="small-section-header">Required methods<a href="#required-methods" class="anchor"></a></h2><div class="methods"><details class="rustdoc-toggle" open><summary><div id="tymethod.custom" class="method has-srclink"><div class="rightside"><a class="srclink" href="../../src/serde/de/mod.rs.html#297" title="goto source code">source</a></div><h4 class="code-header">fn <a href="#tymethod.custom" class="fnname">custom</a><T>(msg: T) -> Self <span class="where fmt-newline">where<br> T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/fmt/trait.Display.html" title="trait core::fmt::Display">Display</a>, </span></h4></div></summary><div class="docblock"><p>Raised when there is general error when deserializing a type.</p> |
| <p>The message should not be capitalized and should not end with a period.</p> |
| |
| <div class='information'><div class='tooltip edition' data-edition="2018">ⓘ</div></div><div class="example-wrap"><pre class="rust rust-example-rendered edition"><code><span class="kw">use</span> <span class="ident">serde::de</span>::{<span class="self">self</span>, <span class="ident">Deserialize</span>, <span class="ident">Deserializer</span>}; |
| |
| <span class="kw">impl</span><span class="op"><</span><span class="lifetime">'de</span><span class="op">></span> <span class="ident">Deserialize</span><span class="op"><</span><span class="lifetime">'de</span><span class="op">></span> <span class="kw">for</span> <span class="ident">IpAddr</span> { |
| <span class="kw">fn</span> <span class="ident">deserialize</span><span class="op"><</span><span class="ident">D</span><span class="op">></span>(<span class="ident">deserializer</span>: <span class="ident">D</span>) -> <span class="prelude-ty">Result</span><span class="op"><</span><span class="self">Self</span>, <span class="ident">D::Error</span><span class="op">></span> |
| <span class="kw">where</span> |
| <span class="ident">D</span>: <span class="ident">Deserializer</span><span class="op"><</span><span class="lifetime">'de</span><span class="op">></span>, |
| { |
| <span class="kw">let</span> <span class="ident">s</span> <span class="op">=</span> <span class="ident">String::deserialize</span>(<span class="ident">deserializer</span>)<span class="question-mark">?</span>; |
| <span class="ident">s</span>.<span class="ident">parse</span>().<span class="ident">map_err</span>(<span class="ident">de::Error::custom</span>) |
| } |
| }</code></pre></div> |
| </div></details></div><h2 id="provided-methods" class="small-section-header">Provided methods<a href="#provided-methods" class="anchor"></a></h2><div class="methods"><details class="rustdoc-toggle" open><summary><div id="method.invalid_type" class="method has-srclink"><div class="rightside"><a class="srclink" href="../../src/serde/de/mod.rs.html#297" title="goto source code">source</a></div><h4 class="code-header">fn <a href="#method.invalid_type" class="fnname">invalid_type</a>(unexp: <a class="enum" href="enum.Unexpected.html" title="enum serde::de::Unexpected">Unexpected</a><'_>, exp: &dyn <a class="trait" href="trait.Expected.html" title="trait serde::de::Expected">Expected</a>) -> Self</h4></div></summary><div class="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><details class="rustdoc-toggle" open><summary><div id="method.invalid_value" class="method has-srclink"><div class="rightside"><a class="srclink" href="../../src/serde/de/mod.rs.html#297" title="goto source code">source</a></div><h4 class="code-header">fn <a href="#method.invalid_value" class="fnname">invalid_value</a>(unexp: <a class="enum" href="enum.Unexpected.html" title="enum serde::de::Unexpected">Unexpected</a><'_>, exp: &dyn <a class="trait" href="trait.Expected.html" title="trait serde::de::Expected">Expected</a>) -> Self</h4></div></summary><div class="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 |
| expected value is a string.</p> |
| </div></details><details class="rustdoc-toggle" open><summary><div id="method.invalid_length" class="method has-srclink"><div class="rightside"><a class="srclink" href="../../src/serde/de/mod.rs.html#297" title="goto source code">source</a></div><h4 class="code-header">fn <a href="#method.invalid_length" class="fnname">invalid_length</a>(len: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.usize.html">usize</a>, exp: &dyn <a class="trait" href="trait.Expected.html" title="trait serde::de::Expected">Expected</a>) -> Self</h4></div></summary><div class="docblock"><p>Raised when deserializing a sequence or map and the input data contains |
| too many or too few elements.</p> |
| <p>The <code>len</code> argument is the number of elements encountered. The sequence |
| or map may have expected more arguments or fewer arguments.</p> |
| <p>The <code>exp</code> argument provides information about what data was being |
| expected. For example <code>exp</code> might say that a tuple of size 6 was |
| expected.</p> |
| </div></details><details class="rustdoc-toggle" open><summary><div id="method.unknown_variant" class="method has-srclink"><div class="rightside"><a class="srclink" href="../../src/serde/de/mod.rs.html#297" title="goto source code">source</a></div><h4 class="code-header">fn <a href="#method.unknown_variant" class="fnname">unknown_variant</a>(variant: &<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.str.html">str</a>, expected: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.slice.html">&'static [</a>&'static <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.str.html">str</a><a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.slice.html">]</a>) -> Self</h4></div></summary><div class="docblock"><p>Raised when a <code>Deserialize</code> enum type received a variant with an |
| unrecognized name.</p> |
| </div></details><details class="rustdoc-toggle" open><summary><div id="method.unknown_field" class="method has-srclink"><div class="rightside"><a class="srclink" href="../../src/serde/de/mod.rs.html#297" title="goto source code">source</a></div><h4 class="code-header">fn <a href="#method.unknown_field" class="fnname">unknown_field</a>(field: &<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.str.html">str</a>, expected: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.slice.html">&'static [</a>&'static <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.str.html">str</a><a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.slice.html">]</a>) -> Self</h4></div></summary><div class="docblock"><p>Raised when a <code>Deserialize</code> struct type received a field with an |
| unrecognized name.</p> |
| </div></details><details class="rustdoc-toggle" open><summary><div id="method.missing_field" class="method has-srclink"><div class="rightside"><a class="srclink" href="../../src/serde/de/mod.rs.html#297" title="goto source code">source</a></div><h4 class="code-header">fn <a href="#method.missing_field" class="fnname">missing_field</a>(field: &'static <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.str.html">str</a>) -> Self</h4></div></summary><div class="docblock"><p>Raised when a <code>Deserialize</code> struct type expected to receive a required |
| field with a particular name but that field was not present in the |
| input.</p> |
| </div></details><details class="rustdoc-toggle" open><summary><div id="method.duplicate_field" class="method has-srclink"><div class="rightside"><a class="srclink" href="../../src/serde/de/mod.rs.html#297" title="goto source code">source</a></div><h4 class="code-header">fn <a href="#method.duplicate_field" class="fnname">duplicate_field</a>(field: &'static <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.str.html">str</a>) -> Self</h4></div></summary><div class="docblock"><p>Raised when a <code>Deserialize</code> struct type received more than one of the |
| same field.</p> |
| </div></details></div><h2 id="implementors" class="small-section-header">Implementors<a href="#implementors" class="anchor"></a></h2><div class="item-list" id="implementors-list"><div id="impl-Error" class="impl has-srclink"><div class="rightside"><a class="srclink" href="../../src/serde/de/value.rs.html#61-82" title="goto source code">source</a></div><a href="#impl-Error" class="anchor"></a><h3 class="code-header in-band">impl <a class="trait" href="trait.Error.html" title="trait serde::de::Error">Error</a> for <a class="struct" href="value/struct.Error.html" title="struct serde::de::value::Error">Error</a></h3></div></div><script type="text/javascript" src="../../implementors/serde/de/trait.Error.js" async></script></section><section id="search" class="content hidden"></section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="serde" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.60.0-nightly (1bd4fdc94 2022-01-12)" ></div> |
| </body></html> |
