1 /*=============================================================================
2   Copyright (c) 2001-2011 Joel de Guzman
3   http://spirit.sourceforge.net/
4 
5   Distributed under the Boost Software License, Version 1.0. (See accompanying
6   file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
7 =============================================================================*/
8 #ifndef BOOST_SPIRIT_MAKE_CONS_OCTOBER_16_2008_1252PM
9 #define BOOST_SPIRIT_MAKE_CONS_OCTOBER_16_2008_1252PM
10 
11 #if defined(_MSC_VER)
12 #pragma once
13 #endif
14 
15 #include <boost/spirit/include/phoenix_limits.hpp>      // needs to be included before proto
16 #include <boost/proto/proto.hpp>
17 #include <boost/mpl/eval_if.hpp>
18 #include <boost/fusion/include/cons.hpp>
19 #include <boost/type_traits/remove_const.hpp>
20 #include <boost/type_traits/is_abstract.hpp>
21 #include <boost/type_traits/is_function.hpp>
22 #include <boost/type_traits/add_reference.hpp>
23 #include <boost/utility/enable_if.hpp>
24 
25 namespace boost { namespace spirit { namespace detail
26 {
27     template <typename T>
28     struct as_meta_element
29       : mpl::eval_if_c<is_abstract<T>::value || is_function<T>::value
30           , add_reference<T>, remove_const<T> >
31     {};
32 
33     template <typename T>
34     struct as_meta_element<T&> : as_meta_element<T>   // always store by value
35     {};
36 
37     template <typename T, int N>
38     struct as_meta_element<T[N]>
39     {
40         typedef const T(&type)[N];
41     };
42 
43     namespace result_of
44     {
45         template <typename Car, typename Cdr = fusion::nil_>
46         struct make_cons
47         {
48             typedef typename as_meta_element<Car>::type car_type;            typedef typename fusion::cons<car_type, Cdr> type;
49         };
50     }
51 
52     template <typename Car, typename Cdr>
53     fusion::cons<typename as_meta_element<Car>::type, Cdr>
make_cons(Car const & car,Cdr const & cdr)54     make_cons(Car const& car, Cdr const& cdr)
55     {
56         typedef typename as_meta_element<Car>::type car_type;
57         typedef typename fusion::cons<car_type, Cdr> result;
58         return result(car, cdr);
59     }
60 
61     template <typename Car>
62     fusion::cons<typename as_meta_element<Car>::type>
make_cons(Car const & car)63     make_cons(Car const& car)
64     {
65         typedef typename as_meta_element<Car>::type car_type;
66         typedef typename fusion::cons<car_type> result;
67         return result(car);
68     }
69 
70 #if defined(__GNUC__) && (__GNUC__ == 4) && (__GNUC_MINOR__ == 0)
71     // workaround for gcc-4.0 bug where illegal function types
72     // can be formed (const is added to function type)
73     // description: http://lists.boost.org/Archives/boost/2009/04/150743.php
74     template <typename Car>
75     fusion::cons<typename as_meta_element<Car>::type>
make_cons(Car & car,typename enable_if<is_function<Car>>::type * =0)76     make_cons(Car& car, typename enable_if<is_function<Car> >::type* = 0)
77     {
78         typedef typename as_meta_element<Car>::type car_type;
79         typedef typename fusion::cons<car_type> result;
80         return result(car);
81     }
82 #endif
83 }}}
84 
85 #endif
86