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<!DOCTYPE HTML>
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Variant attributes
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<!-- Title -->
<h1>
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<a href="." >Variant attributes</a>
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<h1 id="variant-attributes"><a name="variant-attributes" class="plugin-anchor" href="#variant-attributes"><i class="fa fa-link" aria-hidden="true"></i></a>Variant attributes</h1>
<ul>
<li><h5 id="rename"><a name="rename" class="plugin-anchor" href="#rename"><i class="fa fa-link" aria-hidden="true"></i></a><code>#[serde(rename = "name")]</code> </h5>
<p>Serialize and deserialize this variant with the given name instead of its Rust
name.</p>
<p>Allows specifying independent names for serialization vs deserialization:</p>
<ul>
<li><code>#[serde(rename(serialize = "ser_name"))]</code></li>
<li><code>#[serde(rename(deserialize = "de_name"))]</code></li>
<li><code>#[serde(rename(serialize = "ser_name", deserialize = "de_name"))]</code></li>
</ul>
</li>
<li><h5 id="alias"><a name="alias" class="plugin-anchor" href="#alias"><i class="fa fa-link" aria-hidden="true"></i></a><code>#[serde(alias = "name")]</code> </h5>
<p>Deserialize this variant from the given name <em>or</em> from its Rust name. May be
repeated to specify multiple possible names for the same variant.</p>
</li>
<li><h5 id="rename_all"><a name="rename_all" class="plugin-anchor" href="#rename_all"><i class="fa fa-link" aria-hidden="true"></i></a><code>#[serde(rename_all = "...")]</code> </h5>
<p>Rename all the fields of this struct variant according to the given case
convention. The possible values are <code>"lowercase"</code>, <code>"UPPERCASE"</code>,
<code>"PascalCase"</code>, <code>"camelCase"</code>, <code>"snake_case"</code>, <code>"SCREAMING_SNAKE_CASE"</code>,
<code>"kebab-case"</code>, <code>"SCREAMING-KEBAB-CASE"</code>.</p>
<p>Allows specifying independent cases for serialization vs deserialization:</p>
<ul>
<li><code>#[serde(rename_all(serialize = "..."))]</code></li>
<li><code>#[serde(rename_all(deserialize = "..."))]</code></li>
<li><code>#[serde(rename_all(serialize = "...", deserialize = "..."))]</code></li>
</ul>
</li>
<li><h5 id="skip"><a name="skip" class="plugin-anchor" href="#skip"><i class="fa fa-link" aria-hidden="true"></i></a><code>#[serde(skip)]</code> </h5>
<p>Never serialize or deserialize this variant.</p>
</li>
<li><h5 id="skip_serializing"><a name="skip_serializing" class="plugin-anchor" href="#skip_serializing"><i class="fa fa-link" aria-hidden="true"></i></a><code>#[serde(skip_serializing)]</code> </h5>
<p>Never serialize this variant. Trying to serialize this variant is treated as
an error.</p>
</li>
<li><h5 id="skip_deserializing"><a name="skip_deserializing" class="plugin-anchor" href="#skip_deserializing"><i class="fa fa-link" aria-hidden="true"></i></a><code>#[serde(skip_deserializing)]</code> </h5>
<p>Never deserialize this variant.</p>
</li>
<li><h5 id="serialize_with"><a name="serialize_with" class="plugin-anchor" href="#serialize_with"><i class="fa fa-link" aria-hidden="true"></i></a><code>#[serde(serialize_with = "path")]</code> </h5>
<p>Serialize this variant using a function that is different from its
implementation of <code>Serialize</code>. The given function must be callable as
<code>fn<S>(&FIELD0, &FIELD1, ..., S) -> Result<S::Ok, S::Error> where S:
Serializer</code>, although it may also be generic over the <code>FIELD{n}</code> types.
Variants used with <code>serialize_with</code> are not required to be able to derive
<code>Serialize</code>.</p>
<p><code>FIELD{n}</code> exists for every field of the variant. So a unit variant has just
the <code>S</code> argument, and tuple/struct variants have an argument for every field.</p>
</li>
<li><h5 id="deserialize_with"><a name="deserialize_with" class="plugin-anchor" href="#deserialize_with"><i class="fa fa-link" aria-hidden="true"></i></a><code>#[serde(deserialize_with = "path")]</code> </h5>
<p>Deserialize this variant using a function that is different from its
implementation of <code>Deserialize</code>. The given function must be callable as
<code>fn<'de, D>(D) -> Result<FIELDS, D::Error> where D: Deserializer<'de></code>,
although it may also be generic over the elements of <code>FIELDS</code>. Variants used
with <code>deserialize_with</code> are not required be able to derive <code>Deserialize</code>.</p>
<p><code>FIELDS</code> is a tuple of all fields of the variant. A unit variant will have
<code>()</code> as its <code>FIELDS</code> type.</p>
</li>
<li><h5 id="with"><a name="with" class="plugin-anchor" href="#with"><i class="fa fa-link" aria-hidden="true"></i></a><code>#[serde(with = "module")]</code> </h5>
<p>Combination of <code>serialize_with</code> and <code>deserialize_with</code>. Serde will use
<code>$module::serialize</code> as the <code>serialize_with</code> function and
<code>$module::deserialize</code> as the <code>deserialize_with</code> function.</p>
</li>
<li><h5 id="bound"><a name="bound" class="plugin-anchor" href="#bound"><i class="fa fa-link" aria-hidden="true"></i></a><code>#[serde(bound = "T: MyTrait")]</code> </h5>
<p>Where-clause for the <code>Serialize</code> and/or <code>Deserialize</code> impls. This replaces any
trait bounds inferred by Serde for the current variant.</p>
<p>Allows specifying independent bounds for serialization vs deserialization:</p>
<ul>
<li><code>#[serde(bound(serialize = "T: MySerTrait"))]</code></li>
<li><code>#[serde(bound(deserialize = "T: MyDeTrait"))]</code></li>
<li><code>#[serde(bound(serialize = "T: MySerTrait", deserialize = "T: MyDeTrait"))]</code></li>
</ul>
</li>
<li><h5 id="borrow"><a name="borrow" class="plugin-anchor" href="#borrow"><i class="fa fa-link" aria-hidden="true"></i></a><code>#[serde(borrow)]</code> and <code>#[serde(borrow = "'a + 'b + ...")]</code> </h5>
<p>Borrow data for this field from the deserializer by using zero-copy
deserialization. See <a href="lifetimes.html#borrowing-data-in-a-derived-impl">this example</a>.
Only allowed on a newtype variant (a tuple variant with only one field).</p>
</li>
<li><h5 id="other"><a name="other" class="plugin-anchor" href="#other"><i class="fa fa-link" aria-hidden="true"></i></a><code>#[serde(other)]</code> </h5>
<p>Deserialize this variant if the enum tag is anything other than the tag of one
of the other variants in this enum. Only allowed on a unit variant inside of
an internally tagged or adjacently tagged enum.</p>
<p>For example if we have an internally tagged enum with <code>serde(tag = "variant")</code>
containing variants <code>A</code>, <code>B</code>, and <code>Unknown</code> marked <code>serde(other)</code>, the
<code>Unknown</code> variant would be deserialized any time the <code>"variant"</code> field of the
input is neither <code>"A"</code> nor <code>"B"</code>.</p>
</li>
<li><h5 id="untagged"><a name="untagged" class="plugin-anchor" href="#untagged"><i class="fa fa-link" aria-hidden="true"></i></a><code>#[serde(untagged)]</code> </h5>
<p>Irrespective of the <a href="enum-representations.html">enum representation</a>, serialize
and deserialize this variant as untagged, i.e. simply as the variant's data
with no record of the variant name.</p>
<p>Untagged variants must be ordered last in the enum definition.</p>
</li>
</ul>
</section>
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