[#F12F3704ABD60420DD4E4B6563C5FDDCC968F44D]

<div id="F12F3704ABD60420DD4E4B6563C5FDDCC968F44D">
    <div>
        <h2>Class params_ref</h2>
        <p><span>A view representing query parameters in a URL</span></p>


    </div>

    <div>
        <h3>Synopsis</h3>
        <div>
            <code>
                            </code>
        </div>
        <pre class="source-code cpp">
            class params_ref
    : public params_base;
        </pre>
    </div>

    <div>
            <div>
                <h3> Types</h3>
                    </div>
    <div>
            <h3>Types</h3>
            </div>
    <div>
                <h3> Member Functions</h3>
                    </div>
                    </div>

    <div>
        <h3>Description</h3>
        <p><span>Objects of this type are used to interpret</span> <span>the query parameters as a bidirectional view</span>
<span>of key/value pairs.</span>
<span>The view does not retain ownership of the</span>
<span>elements and instead references the original</span>
<span>url. The caller is responsible for ensuring</span>
<span>that the lifetime of the referenced url</span>
<span>extends until it is no longer referenced.</span>
<span>The view is modifiable; calling non-const</span>
<span>members causes changes to the referenced</span>
<span>url.</span></p>

<p><span></span></p>

<p><span>Percent escapes in strings returned when</span>
<span>dereferencing iterators are automatically</span>
<span>decoded.</span>
<span>Reserved characters in strings supplied</span>
<span>to modifier functions are automatically</span>
<span>percent-escaped.</span></p>

<h3>Example</h3>
<code>
url u( "?first=John&last=Doe" );

params_ref p = u.params();
</code>
<h3>Iterator Invalidation</h3>
<p><span>Changes to the underlying character buffer</span>
<span>can invalidate iterators which reference it.</span>
<span>Modifications made through the container</span>
<span>invalidate some or all iterators:</span>
<span></span></p>

<li><span>append</span>
<span>: Only `end()`.</span></li>
<li><span>assign</span>
<span>,</span>
<span>clear</span>
<span>,        `operator=` : All elements.</span></li>
<li><span>erase</span>
<span>: Erased elements and all</span>
<span>elements after (including `end()`).</span></li>
<li><span>insert</span>
<span>: All elements at or after</span>
<span>the insertion point (including `end()`).</span></li>
<li><span>replace</span>
<span>,</span>
<span>set</span>
<span>: Modified</span>
<span>elements and all elements</span>
<span>after (including `end()`).</span></li>

    </div>

</div>