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2018-08-22 17:04:13 +00:00
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<h1 class='fqn'><span class='in-band'>Function <a href='../index.html'>serde_json</a>::<wbr><a href='index.html'>de</a>::<wbr><a class="fn" href=''>from_str</a></span><span class='out-of-band'><span id='render-detail'>
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</span><a class='srclink' href='../../src/serde_json/de.rs.html#2260-2265' title='goto source code'>[src]</a></span></h1>
<pre class='rust fn'>pub fn from_str&lt;'a, T&gt;(s: &amp;'a <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.str.html">str</a>) -&gt; <a class="type" href="../../serde_json/type.Result.html" title="type serde_json::Result">Result</a>&lt;T&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;T: <a class="trait" href="../../serde/de/trait.Deserialize.html" title="trait serde::de::Deserialize">Deserialize</a>&lt;'a&gt;,&nbsp;</span></pre><div class='docblock'><p>Deserialize an instance of type <code>T</code> from a string of JSON text.</p>
<h1 id="errors" class="section-header"><a href="#errors">Errors</a></h1>
<p>This conversion can fail if the structure of the input does not match the
structure expected by <code>T</code>, for example if <code>T</code> is a struct type but the input
contains something other than a JSON map. It can also fail if the structure
is correct but <code>T</code>'s implementation of <code>Deserialize</code> decides that something
is wrong with the data, for example required struct fields are missing from
the JSON map or some number is too big to fit in the expected primitive
type.</p>
<pre class="rust rust-example-rendered">
<span class="attribute">#[<span class="ident">macro_use</span>]</span>
<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">serde_derive</span>;
<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">serde</span>;
<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">serde_json</span>;
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Deserialize</span>, <span class="ident">Debug</span>)]</span>
<span class="kw">struct</span> <span class="ident">User</span> {
<span class="ident">fingerprint</span>: <span class="ident">String</span>,
<span class="ident">location</span>: <span class="ident">String</span>,
}
<span class="kw">fn</span> <span class="ident">main</span>() {
<span class="comment">// The type of `j` is `&amp;str`</span>
<span class="kw">let</span> <span class="ident">j</span> <span class="op">=</span> <span class="string">&quot;{
\&quot;fingerprint\&quot;: \&quot;0xF9BA143B95FF6D82\&quot;,
\&quot;location\&quot;: \&quot;Menlo Park, CA\&quot;
}&quot;</span>;
<span class="kw">let</span> <span class="ident">u</span>: <span class="ident">User</span> <span class="op">=</span> <span class="ident">serde_json</span>::<span class="ident">from_str</span>(<span class="ident">j</span>).<span class="ident">unwrap</span>();
<span class="macro">println</span><span class="macro">!</span>(<span class="string">&quot;{:#?}&quot;</span>, <span class="ident">u</span>);
}</pre>
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