1 <?xml version=
"1.0" encoding=
"utf-8"?>
3 Copyright 2012 Eric Niebler
5 Distributed under the Boost
6 Software License, Version 1.0. (See accompanying
7 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
9 <header name=
"boost/proto/context/null.hpp">
12 <computeroutput><classname alt=
"boost::proto::context::null_context">proto::context::null_context
<></classname></computeroutput>,
13 an evaluation context for
14 <computeroutput><functionname alt=
"boost::proto::eval">proto::eval()
</functionname></computeroutput>
15 that simply evaluates each child expression, doesn't combine the results at all, and returns void.
17 <namespace name=
"boost">
18 <namespace name=
"proto">
19 <namespace name=
"context">
20 <struct name=
"null_eval">
22 <template-type-parameter name=
"Expr"/>
23 <template-type-parameter name=
"Context"/>
25 <typedef name=
"result_type">
28 <method-group name=
"public member functions">
29 <method name=
"operator()" cv=
"const">
31 <parameter name=
"expr">
32 <paramtype>Expr
&</paramtype>
34 <parameter name=
"context">
35 <paramtype>Context
&</paramtype>
39 For
<computeroutput>N
</computeroutput> in
<computeroutput>[
0,Expr arity)
</computeroutput>,
41 <programlisting><functionname>proto::eval
</functionname>(
<functionname>proto::child_c
</functionname><N
>(expr), context)
</programlisting>
48 <struct name=
"null_context">
49 <purpose>An evaluation context for
<functionname alt=
"proto::eval">proto::eval()
</functionname> that simply evaluates
50 each child expression, doesn't combine the results at all, and returns void.
</purpose>
53 <template-type-parameter name=
"Expr"/>
54 <template-type-parameter name=
"ThisContext">
55 <default>null_context const
</default>
56 </template-type-parameter>
58 <inherit><classname>proto::context::null_eval
</classname>< Expr, ThisContext
></inherit>