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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="Convert a `T` into `serde_json::Value` which is an enum that can represent any valid JSON data."><title>to_value in serde_json - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-6b053e98.ttf.woff2,FiraSans-Regular-0fe48ade.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" crossorigin href="../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../static.files/normalize-9960930a.css"><link rel="stylesheet" href="../static.files/rustdoc-42caa33d.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="1.84.1 (e71f9a9a9 2025-01-27)" data-channel="1.84.1" data-search-js="search-92e6798f.js" data-settings-js="settings-0f613d39.js" ><script src="../static.files/storage-59e33391.js"></script><script defer src="sidebar-items.js"></script><script defer src="../static.files/main-5f194d8c.js"></script><noscript><link rel="stylesheet" href="../static.files/noscript-893ab5e7.css"></noscript><link rel="alternate icon" type="image/png" href="../static.files/favicon-32x32-6580c154.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]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle" title="show sidebar"></button></nav><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../serde_json/index.html">serde_<wbr>json</a><span class="version">1.0.133</span></h2></div><div class="sidebar-elems"><section id="rustdoc-toc"><h2 class="location"><a href="#">to_<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"></div><main><div class="width-limiter"><rustdoc-search></rustdoc-search><section id="main-content" class="content"><div class="main-heading"><span class="rustdoc-breadcrumbs"><a href="index.html">serde_json</a></span><h1>Function <span class="fn">to_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#988-993">Source</a> </span></div><pre class="rust item-decl"><code>pub fn to_value&lt;T&gt;(value: T) -&gt; <a class="enum" href="https://doc.rust-lang.org/1.84.1/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;<a class="enum" href="enum.Value.html" title="enum serde_json::Value">Value</a>, <a class="struct" href="struct.Error.html" title="struct serde_json::Error">Error</a>&gt;<div class="where">where
T: <a class="trait" href="../serde/ser/trait.Serialize.html" title="trait serde::ser::Serialize">Serialize</a>,</div></code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Convert a <code>T</code> into <code>serde_json::Value</code> which is an enum that can represent
any valid JSON data.</p>
<h2 id="example"><a class="doc-anchor" href="#example">§</a>Example</h2>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>serde::Serialize;
<span class="kw">use </span>serde_json::json;
<span class="kw">use </span>std::error::Error;
<span class="attr">#[derive(Serialize)]
</span><span class="kw">struct </span>User {
fingerprint: String,
location: String,
}
<span class="kw">fn </span>compare_json_values() -&gt; <span class="prelude-ty">Result</span>&lt;(), Box&lt;<span class="kw">dyn </span>Error&gt;&gt; {
<span class="kw">let </span>u = User {
fingerprint: <span class="string">"0xF9BA143B95FF6D82"</span>.to_owned(),
location: <span class="string">"Menlo Park, CA"</span>.to_owned(),
};
<span class="comment">// The type of `expected` is `serde_json::Value`
</span><span class="kw">let </span>expected = <span class="macro">json!</span>({
<span class="string">"fingerprint"</span>: <span class="string">"0xF9BA143B95FF6D82"</span>,
<span class="string">"location"</span>: <span class="string">"Menlo Park, CA"</span>,
});
<span class="kw">let </span>v = serde_json::to_value(u).unwrap();
<span class="macro">assert_eq!</span>(v, expected);
<span class="prelude-val">Ok</span>(())
}</code></pre></div>
<h2 id="errors"><a class="doc-anchor" href="#errors">§</a>Errors</h2>
<p>This conversion can fail if <code>T</code>s implementation of <code>Serialize</code> decides to
fail, or if <code>T</code> contains a map with non-string keys.</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>std::collections::BTreeMap;
<span class="kw">fn </span>main() {
<span class="comment">// The keys in this map are vectors, not strings.
</span><span class="kw">let </span><span class="kw-2">mut </span>map = BTreeMap::new();
map.insert(<span class="macro">vec!</span>[<span class="number">32</span>, <span class="number">64</span>], <span class="string">"x86"</span>);
<span class="macro">println!</span>(<span class="string">"{}"</span>, serde_json::to_value(map).unwrap_err());
}</code></pre></div>
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