[#FA6D558C8D31B60CA4166BD1C5E72A6645C904D8]

<div id="FA6D558C8D31B60CA4166BD1C5E72A6645C904D8">
    <div>
        <h2>Function <a href="#">params_base</a>::
contains</h2>
        <p><span>Return true if a matching key exists</span></p>


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    <div>
        <h3>Synopsis</h3>
        <div>
            <code>
                            </code>
        </div>
        <pre class="source-code cpp">
            bool
contains(
    core::string_view key,
    ignore_case_param ic = = {}) const noexcept;
        </pre>
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    <div>
        <h3>Description</h3>
        <p><span>This function examines the parameters</span> <span>in the container to find a match for</span>
<span>the specified key.</span>
<span>The comparison is performed as if all</span>
<span>escaped characters were decoded first.</span></p>

<h3>Example</h3>
<code>
assert( url_view( "?first=John&last=Doe" ).params().contains( "first" ) );
</code>
<h3>Complexity</h3>
<p><span>Linear in `this->buffer().size()`.</span></p>

<h3>Exception Safety</h3>
<p><span>Throws nothing.</span></p>


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