boost-react-native-bundle
Version:
Boost library as in https://sourceforge.net/projects/boost/files/boost/1.57.0/
228 lines (226 loc) • 10.9 kB
text/xml
<!--
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/transform/default.hpp">
<namespace name="boost">
<namespace name="proto">
<struct name="_default">
<template>
<template-type-parameter name="Grammar">
<default><replaceable>unspecified</replaceable></default>
</template-type-parameter>
</template>
<inherit><classname>proto::transform</classname>< _default<Grammar> ></inherit>
<purpose>A <conceptname>PrimitiveTransform</conceptname> that gives expressions their
usual C++ behavior</purpose>
<description>
<para>
For the complete description of the behavior of the <computeroutput>proto::_default</computeroutput>
transform, see the documentation for the nested <computeroutput>
<classname>proto::_default::impl<></classname>
</computeroutput> class template.
</para>
<para>
When used without specifying a <computeroutput>Grammar</computeroutput> parameter,
<computeroutput>proto::_default</computeroutput> behaves as if the parameter were
<computeroutput>proto::_default<></computeroutput>.
</para>
</description>
<struct name="impl">
<template>
<template-type-parameter name="Expr"/>
<template-type-parameter name="State"/>
<template-type-parameter name="Data"/>
</template>
<inherit><type><classname>proto::transform_impl</classname><Expr, State, Data></type></inherit>
<typedef name="Tag">
<purpose>For exposition only</purpose>
<type>typename Expr::tag_type</type>
</typedef>
<data-member name="s_expr" specifiers="static">
<purpose>For exposition only</purpose>
<type>Expr</type>
</data-member>
<data-member name="s_state" specifiers="static">
<purpose>For exposition only</purpose>
<type>State</type>
</data-member>
<data-member name="s_data" specifiers="static">
<purpose>For exposition only</purpose>
<type>Data</type>
</data-member>
<typedef name="result_type">
<type><emphasis>see-below</emphasis></type>
<description>
<itemizedlist>
<listitem>
<para>
If <computeroutput>Tag</computeroutput> corresponds to a unary prefix operator,
then the result type is
<programlisting>decltype(
OP Grammar()(<functionname>proto::child</functionname>(s_expr), s_state, s_data)
)</programlisting>
</para>
</listitem>
<listitem>
<para>
If <computeroutput>Tag</computeroutput> corresponds to a unary postfix operator,
then the result type is
<programlisting>decltype(
Grammar()(<functionname>proto::child</functionname>(s_expr), s_state, s_data) OP
)</programlisting>
</para>
</listitem>
<listitem>
<para>
If <computeroutput>Tag</computeroutput> corresponds to a binary infix operator,
then the result type is
<programlisting>decltype(
Grammar()(<functionname>proto::left</functionname>(s_expr), s_state, s_data) OP
Grammar()(<functionname>proto::right</functionname>(s_expr), s_state, s_data)
)</programlisting>
</para>
</listitem>
<listitem>
<para>
If <computeroutput>Tag</computeroutput> is <computeroutput>
<classname>proto::tag::subscript</classname>
</computeroutput>,
then the result type is
<programlisting>decltype(
Grammar()(<functionname>proto::left</functionname>(s_expr), s_state, s_data) [
Grammar()(<functionname>proto::right</functionname>(s_expr), s_state, s_data) ]
)</programlisting>
</para>
</listitem>
<listitem>
<para>
If <computeroutput>Tag</computeroutput> is <computeroutput>
<classname>proto::tag::if_else_</classname>
</computeroutput>,
then the result type is
<programlisting>decltype(
Grammar()(<functionname>proto::child_c</functionname><0>(s_expr), s_state, s_data) ?
Grammar()(<functionname>proto::child_c</functionname><1>(s_expr), s_state, s_data) :
Grammar()(<functionname>proto::child_c</functionname><2>(s_expr), s_state, s_data)
)</programlisting>
</para>
</listitem>
<listitem>
<para>
If <computeroutput>Tag</computeroutput> is <computeroutput>
<classname>proto::tag::function</classname>
</computeroutput>,
then the result type is
<programlisting>decltype(
Grammar()(<functionname>proto::child_c</functionname><0>(s_expr), s_state, s_data) (
Grammar()(<functionname>proto::child_c</functionname><1>(s_expr), s_state, s_data),
...
Grammar()(<functionname>proto::child_c</functionname><N>(s_expr), s_state, s_data) )
)</programlisting>
</para>
</listitem>
</itemizedlist>
</description>
</typedef>
<description>
<para>
Let <computeroutput><computeroutput>OP</computeroutput></computeroutput> be the C++ operator
corresponding to <computeroutput>Expr::proto_tag</computeroutput>. (For example, if
<computeroutput>Tag</computeroutput> is <computeroutput>
<classname>proto::tag::plus</classname></computeroutput>, let <computeroutput>
<computeroutput>OP</computeroutput></computeroutput> be <computeroutput>+</computeroutput>.)
</para>
</description>
<method-group name="public member functions">
<method name="operator()" cv="const">
<type>result_type</type>
<parameter name="expr">
<paramtype>typename impl::expr_param</paramtype>
</parameter>
<parameter name="state">
<paramtype>typename impl::state_param</paramtype>
</parameter>
<parameter name="data">
<paramtype>typename impl::data_param</paramtype>
</parameter>
<description>
<computeroutput>
<classname>proto::_default</classname><Grammar>::impl<Expr, State, Data>::operator()
</computeroutput> returns the following:
<itemizedlist>
<listitem>
<para>
If <computeroutput>Tag</computeroutput> corresponds to a unary prefix operator,
then return
<programlisting>OP Grammar()(<functionname>proto::child</functionname>(expr), state, data)</programlisting>
</para>
</listitem>
<listitem>
<para>
If <computeroutput>Tag</computeroutput> corresponds to a unary postfix operator,
then return
<programlisting>Grammar()(<functionname>proto::child</functionname>(expr), state, data) OP</programlisting>
</para>
</listitem>
<listitem>
<para>
If <computeroutput>Tag</computeroutput> corresponds to a binary infix operator,
then return
<programlisting>Grammar()(<functionname>proto::left</functionname>(expr), state, data) OP
Grammar()(<functionname>proto::right</functionname>(expr), state, data)</programlisting>
</para>
</listitem>
<listitem>
<para>
If <computeroutput>Tag</computeroutput> is <computeroutput>
<classname>proto::tag::subscript</classname>
</computeroutput>,
then return
<programlisting>Grammar()(<functionname>proto::left</functionname>(expr), state, data) [
Grammar()(<functionname>proto::right</functionname>(expr), state, data) ]</programlisting>
</para>
</listitem>
<listitem>
<para>
If <computeroutput>Tag</computeroutput> is <computeroutput>
<classname>proto::tag::if_else_</classname>
</computeroutput>,
then return
<programlisting>Grammar()(<functionname>proto::child_c</functionname><0>(expr), state, data) ?
Grammar()(<functionname>proto::child_c</functionname><1>(expr), state, data) :
Grammar()(<functionname>proto::child_c</functionname><2>(expr), state, data)</programlisting>
</para>
</listitem>
<listitem>
<para>
If <computeroutput>Tag</computeroutput> is <computeroutput>
<classname>proto::tag::function</classname>
</computeroutput>,
then return
<programlisting>Grammar()(<functionname>proto::child_c</functionname><0>(expr), state, data) (
Grammar()(<functionname>proto::child_c</functionname><1>(expr), state, data),
...
Grammar()(<functionname>proto::child_c</functionname><N>(expr), state, data) )</programlisting>
</para>
</listitem>
</itemizedlist>
</description>
</method>
</method-group>
<description>
<para>
The behavior of this class is specified in terms of the C++0x <computeroutput>decltype</computeroutput>
keyword. In systems where this keyword is not available, Proto uses the Boost.Typeof library to
approximate the behavior.
</para>
</description>
</struct>
</struct>
</namespace>
</namespace>
</header>