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30 lines
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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="Interpret a `serde_json::Value` as an instance of type `T`."><title>from_value in serde_json - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-6b053e98.ttf.woff2,FiraSans-Italic-81dc35de.woff2,FiraSans-Regular-0fe48ade.woff2,FiraSans-MediumItalic-ccf7e434.woff2,FiraSans-Medium-e1aa3f0a.woff2,SourceCodePro-Regular-8badfe75.ttf.woff2,SourceCodePro-Semibold-aa29a496.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2"href="../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../static.files/normalize-9960930a.css"><link rel="stylesheet" href="../static.files/rustdoc-ca0dd0c4.css"><meta name="rustdoc-vars" data-root-path="../" data-static-root-path="../static.files/" data-current-crate="serde_json" data-themes="" data-resource-suffix="" data-rustdoc-version="1.93.1 (01f6ddf75 2026-02-11) (Arch Linux rust 1:1.93.1-1)" data-channel="1.93.1" data-search-js="search-9e2438ea.js" data-stringdex-js="stringdex-a3946164.js" data-settings-js="settings-c38705f0.js" ><script src="../static.files/storage-e2aeef58.js"></script><script defer src="sidebar-items.js"></script><script defer src="../static.files/main-a410ff4d.js"></script><noscript><link rel="stylesheet" href="../static.files/noscript-263c88ec.css"></noscript><link rel="alternate icon" type="image/png" href="../static.files/favicon-32x32-eab170b8.png"><link rel="icon" type="image/svg+xml" href="../static.files/favicon-044be391.svg"></head><body class="rustdoc fn"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><rustdoc-topbar><h2><a href="#">from_value</a></h2></rustdoc-topbar><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../serde_json/index.html">serde_<wbr>json</a><span class="version">1.0.149</span></h2></div><div class="sidebar-elems"><section id="rustdoc-toc"><h2 class="location"><a href="#">from_<wbr>value</a></h2><h3><a href="#">Sections</a></h3><ul class="block top-toc"><li><a href="#example" title="Example">Example</a></li><li><a href="#errors" title="Errors">Errors</a></li></ul></section><div id="rustdoc-modnav"><h2 class="in-crate"><a href="index.html">In crate serde_<wbr>json</a></h2></div></div></nav><div class="sidebar-resizer" title="Drag to resize sidebar"></div><main><div class="width-limiter"><section id="main-content" class="content"><div class="main-heading"><div class="rustdoc-breadcrumbs"><a href="index.html">serde_json</a></div><h1>Function <span class="fn">from_<wbr>value</span> <button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><rustdoc-toolbar></rustdoc-toolbar><span class="sub-heading"><a class="src" href="../src/serde_json/value/mod.rs.html#1037-1042">Source</a> </span></div><pre class="rust item-decl"><code>pub fn from_value<T>(value: <a class="enum" href="enum.Value.html" title="enum serde_json::Value">Value</a>) -> <a class="enum" href="https://doc.rust-lang.org/1.93.1/core/result/enum.Result.html" title="enum core::result::Result">Result</a><T, <a class="struct" href="struct.Error.html" title="struct serde_json::Error">Error</a>><div class="where">where
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T: <a class="trait" href="../serde_core/de/trait.DeserializeOwned.html" title="trait serde_core::de::DeserializeOwned">DeserializeOwned</a>,</div></code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Interpret a <code>serde_json::Value</code> as an instance of type <code>T</code>.</p>
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<h2 id="example"><a class="doc-anchor" href="#example">§</a>Example</h2>
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<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>serde::Deserialize;
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<span class="kw">use </span>serde_json::json;
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<span class="attr">#[derive(Deserialize, Debug)]
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</span><span class="kw">struct </span>User {
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fingerprint: String,
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location: String,
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}
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<span class="kw">fn </span>main() {
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<span class="comment">// The type of `j` is `serde_json::Value`
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</span><span class="kw">let </span>j = <span class="macro">json!</span>({
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<span class="string">"fingerprint"</span>: <span class="string">"0xF9BA143B95FF6D82"</span>,
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<span class="string">"location"</span>: <span class="string">"Menlo Park, CA"
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</span>});
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<span class="kw">let </span>u: User = serde_json::from_value(j).unwrap();
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<span class="macro">println!</span>(<span class="string">"{:#?}"</span>, u);
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}</code></pre></div><h2 id="errors"><a class="doc-anchor" href="#errors">§</a>Errors</h2>
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<p>This conversion can fail if the structure of the Value does not match the
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structure expected by <code>T</code>, for example if <code>T</code> is a struct type but the Value
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contains something other than a JSON map. It can also fail if the structure
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is correct but <code>T</code>’s implementation of <code>Deserialize</code> decides that something
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is wrong with the data, for example required struct fields are missing from
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the JSON map or some number is too big to fit in the expected primitive
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type.</p>
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</div></details></section></div></main></body></html> |