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<span class=k>using</span><span class=w> </span><span class=n>json_serializer</span><span class=w> </span><span class=o>=</span><span class=w> </span><span class=n>JSONSerializer</span><span class=o>&lt;</span><span class=n>T</span><span class=p>,</span><span class=w> </span><span class=n>SFINAE</span><span class=o>&gt;</span><span class=p>;</span>
</code></pre></div> <h2 id=template-parameters>Template parameters<a class=headerlink href=#template-parameters title="Permanent link">&para;</a></h2> <dl> <dt><code>T</code></dt> <dd>type to convert; will be used in the <code>to_json</code>/<code>from_json</code> functions</dd> <dt><code>SFINAE</code></dt> <dd>type to add compile type checks via <abbr title="Substitution failure is not an error">SFINAE</abbr>; usually <code class=highlight><span class=kt>void</span></code></dd> </dl> <h2 id=notes>Notes<a class=headerlink href=#notes title="Permanent link">&para;</a></h2> <h3 id=default-type>Default type<a class=headerlink href=#default-type title="Permanent link">&para;</a></h3> <p>The default values for <code>json_serializer</code> is <a href=../../adl_serializer/ ><code>adl_serializer</code></a>.</p> <h3 id=requirements>Requirements<a class=headerlink href=#requirements title="Permanent link">&para;</a></h3> <p>A custom serializer must provide <code class=highlight><span class=k>static</span><span class=w> </span><span class=kt>void</span><span class=w> </span><span class=n>to_json</span><span class=p>(</span><span class=n>basic_json</span><span class=o>&amp;</span><span class=p>,</span><span class=w> </span><span class=n>T</span><span class=p>)</span></code> for every type it serializes, and either <code class=highlight><span class=k>static</span><span class=w> </span><span class=kt>void</span><span class=w> </span><span class=n>from_json</span><span class=p>(</span><span class=k>const</span><span class=w> </span><span class=n>basic_json</span><span class=o>&amp;</span><span class=p>,</span><span class=w> </span><span class=n>T</span><span class=o>&amp;</span><span class=p>)</span></code> or <code class=highlight><span class=k>static</span><span class=w> </span><span class=n>T</span><span class=w> </span><span class=n>from_json</span><span class=p>(</span><span class=k>const</span><span class=w> </span><span class=n>basic_json</span><span class=o>&amp;</span><span class=p>)</span></code> for every type it deserializes. See <a href=../../../features/types/template_parameters/#jsonserializer>Template Parameter Requirements</a>.</p> <h2 id=examples>Examples<a class=headerlink href=#examples title="Permanent link">&para;</a></h2> <details class=example> <summary>Example</summary> <p>The example below shows how a conversion of a non-default-constructible type is implemented via a specialization of the <code>adl_serializer</code>.</p> <div class=highlight><pre><span></span><code><span class=cp>#include</span><span class=w> </span><span class=cpf>&lt;iostream&gt;</span>
<span class=cp>#include</span><span class=w> </span><span class=cpf>&lt;nlohmann/json.hpp&gt;</span>