boost/libs/proto/doc/reference/literal.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
  Copyright 2012 Eric Niebler

  Distributed under the Boost
  Software License, Version 1.0. (See accompanying
  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  -->
<header name="boost/proto/literal.hpp">
  <para>
    The
    <computeroutput><classname alt="boost::proto::literal">proto::literal&lt;&gt;</classname></computeroutput>
    terminal wrapper, and the
    <computeroutput><functionname alt="boost::proto::lit">proto::lit()</functionname></computeroutput>
    function for creating
    <computeroutput><classname alt="boost::proto::literal">proto::literal&lt;&gt;</classname></computeroutput>
    wrappers.
  </para>
  <namespace name="boost">
    <namespace name="proto">
      <struct name="literal">
        <template>
          <template-type-parameter name="T"/>
          <template-type-parameter name="Domain">
            <default><classname>proto::default_domain</classname></default>
          </template-type-parameter>
        </template>
        <inherit>
          <type>
  <classname>proto::extends</classname>&lt;<classname>proto::basic_expr</classname>&lt;<classname>proto::tag::terminal</classname>, <classname>proto::term</classname>&lt; T &gt; &gt;, proto::literal&lt;T, Domain&gt;, Domain&gt;</type>
        </inherit>
        <purpose>A simple wrapper for a terminal, provided for ease of use.</purpose>
        <description>
          <para>
            A simple wrapper for a terminal, provided for ease of use. In all cases,
            <computeroutput>proto::literal&lt;X&gt; l(x);</computeroutput> is equivalent to
            <computeroutput><classname>proto::terminal</classname>&lt;X&gt;::type l = {x};</computeroutput>.
          </para>
          <para>
            The <computeroutput>Domain</computeroutput> template parameter defaults to
            <computeroutput><classname>proto::default_domain</classname></computeroutput>.
          </para>
        </description>
        <typedef name="X">
          <purpose>For exposition only</purpose>
          <type><classname>proto::basic_expr</classname>&lt;<classname>proto::tag::terminal</classname>, <classname>proto::term</classname>&lt; T &gt; &gt;</type>
        </typedef>
        <typedef name="value_type">
          <type>typename <classname>proto::result_of::value</classname>&lt;X&gt;::type</type>
        </typedef>
        <typedef name="reference">
          <type>typename <classname>proto::result_of::value</classname>&lt;X &amp;&gt;::type</type>
        </typedef>
        <typedef name="const_reference">
          <type>typename <classname>proto::result_of::value</classname>&lt;X const &amp;&gt;::type</type>
        </typedef>
        <method-group name="public member functions">
          <method name="get">
            <type>reference</type>
            <returns>
              <computeroutput><functionname>proto::value</functionname>(*this)</computeroutput>
            </returns>
          </method>
          <method name="get" cv="const">
            <type>const_reference</type>
            <returns>
              <computeroutput><functionname>proto::value</functionname>(*this)</computeroutput>
            </returns>
          </method>
        </method-group>
        <constructor/>
        <constructor>
          <template>
            <template-type-parameter name="U"/>
          </template>
          <parameter name="u">
            <paramtype>U &amp;</paramtype>
          </parameter>
        </constructor>
        <constructor>
          <template>
            <template-type-parameter name="U"/>
          </template>
          <parameter name="u">
            <paramtype>U const &amp;</paramtype>
          </parameter>
        </constructor>
        <constructor>
          <template>
            <template-type-parameter name="U"/>
          </template>
          <parameter name="u">
            <paramtype><classname>proto::literal</classname>&lt; U, Domain &gt; const &amp;</paramtype>
          </parameter>
        </constructor>
      </struct>
      
      <!-- proto::lit() -->
      <overloaded-function name="lit">
        <signature>
          <type><classname>proto::literal</classname>&lt; T &amp; &gt; const</type>
          <template>
            <template-type-parameter name="T"/>
          </template>
          <parameter name="t">
            <paramtype>T &amp;</paramtype>
            <description>
              <para>The object to wrap.</para>
            </description>
          </parameter>
        </signature>
        <signature>
          <type><classname>proto::literal</classname>&lt; T const &amp; &gt; const</type>
          <template>
            <template-type-parameter name="T"/>
          </template>
          <parameter name="t">
            <paramtype>T const &amp;</paramtype>
          </parameter>
        </signature>
        <purpose>A helper function for creating a <computeroutput>
          <classname alt="proto::literal">proto::literal&lt;&gt;</classname></computeroutput> wrapper.
        </purpose>
        <returns>
          <para>
            <computeroutput><classname>proto::literal</classname>&lt;T &amp;&gt;(t)</computeroutput>
          </para>
        </returns>
        <throws>
          <simpara>Will not throw.</simpara>
        </throws>
        <notes>
          <para>The returned value holds the argument by reference. </para>
        </notes>
      </overloaded-function>
    </namespace>
  </namespace>
</header>