ceph/src/boost/boost/spirit/home/karma/detail/as.hpp

   1 //  Copyright (c) 2001-2011 Hartmut Kaiser
   2 //
   3 //  Distributed under the Boost Software License, Version 1.0. (See accompanying
   4 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   5
   6 #if !defined(BOOST_SPIRIT_KARMA_AS_STRING_DEC_18_0644PM)
   7 #define BOOST_SPIRIT_KARMA_AS_STRING_DEC_18_0644PM
   8
   9 #if defined(_MSC_VER)
  10 #pragma once
  11 #endif
  12
  13 #include <boost/spirit/home/support/unused.hpp>
  14 #include <boost/spirit/home/support/attributes_fwd.hpp>
  15
  16 ///////////////////////////////////////////////////////////////////////////////
  17 namespace boost { namespace spirit { namespace traits
  18 {
  19     ///////////////////////////////////////////////////////////////////////////
  20     //  This file contains the attribute to string conversion utility. The
  21     //  utility provided also accept spirit's unused_type; all no-ops. Compiler
  22     //  optimization will easily strip these away.
  23     ///////////////////////////////////////////////////////////////////////////
  24
  25     ///////////////////////////////////////////////////////////////////////////
  26     template <typename T, typename Attribute>
  27     inline typename spirit::result_of::attribute_as<T, Attribute>::type
  28     as(Attribute const& attr)
  29     {
  30         return attribute_as<T, Attribute>::call(attr);
  31     }
  32
  33     template <typename T>
  34     inline unused_type as(unused_type)
  35     {
  36         return unused;
  37     }
  38
  39     ///////////////////////////////////////////////////////////////////////////
  40     template <typename T, typename Attribute>
  41     inline bool valid_as(Attribute const& attr)
  42     {
  43         return attribute_as<T, Attribute>::is_valid(attr);
  44     }
  45
  46     template <typename T>
  47     inline bool valid_as(unused_type)
  48     {
  49         return true;
  50     }
  51 }}}
  52
  53 ///////////////////////////////////////////////////////////////////////////////
  54 namespace boost { namespace spirit { namespace result_of
  55 {
  56     template <typename T, typename Attribute>
  57     struct attribute_as
  58       : traits::attribute_as<T, Attribute>
  59     {};
  60
  61     template <typename T>
  62     struct attribute_as<T, unused_type>
  63     {
  64         typedef unused_type type;
  65     };
  66
  67     template <typename T>
  68     struct attribute_as<T, unused_type const>
  69     {
  70         typedef unused_type type;
  71     };
  72 }}}
  73
  74 #endif