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/mpl/eval_if.hpp>
16 #include <boost/fusion/include/cons.hpp>
17 #include <boost/type_traits/remove_const.hpp>
18 #include <boost/type_traits/is_abstract.hpp>
19 #include <boost/type_traits/is_function.hpp>
20 #include <boost/type_traits/add_reference.hpp>
21 #include <boost/utility/enable_if.hpp>
22 
23 namespace boost { namespace spirit { namespace detail
24 {
25     template <typename T>
26     struct as_meta_element
27       : mpl::eval_if_c<is_abstract<T>::value || is_function<T>::value
28           , add_reference<T>, remove_const<T> >
29     {};
30 
31     template <typename T>
32     struct as_meta_element<T&> : as_meta_element<T>   // always store by value
33     {};
34 
35     template <typename T, int N>
36     struct as_meta_element<T[N]>
37     {
38         typedef const T(&type)[N];
39     };
40 
41     namespace result_of
42     {
43         template <typename Car, typename Cdr = fusion::nil_>
44         struct make_cons
45         {
46             typedef typename as_meta_element<Car>::type car_type;            typedef typename fusion::cons<car_type, Cdr> type;
47         };
48     }
49 
50     template <typename Car, typename Cdr>
51     fusion::cons<typename as_meta_element<Car>::type, Cdr>
make_cons(Car const & car,Cdr const & cdr)52     make_cons(Car const& car, Cdr const& cdr)
53     {
54         typedef typename as_meta_element<Car>::type car_type;
55         typedef typename fusion::cons<car_type, Cdr> result;
56         return result(car, cdr);
57     }
58 
59     template <typename Car>
60     fusion::cons<typename as_meta_element<Car>::type>
make_cons(Car const & car)61     make_cons(Car const& car)
62     {
63         typedef typename as_meta_element<Car>::type car_type;
64         typedef typename fusion::cons<car_type> result;
65         return result(car);
66     }
67 
68 #if defined(__GNUC__) && (__GNUC__ == 4) && (__GNUC_MINOR__ == 0)
69     // workaround for gcc-4.0 bug where illegal function types
70     // can be formed (const is added to function type)
71     // description: http://lists.boost.org/Archives/boost/2009/04/150743.php
72     template <typename Car>
73     fusion::cons<typename as_meta_element<Car>::type>
make_cons(Car & car,typename enable_if<is_function<Car>>::type * =0)74     make_cons(Car& car, typename enable_if<is_function<Car> >::type* = 0)
75     {
76         typedef typename as_meta_element<Car>::type car_type;
77         typedef typename fusion::cons<car_type> result;
78         return result(car);
79     }
80 #endif
81 }}}
82 
83 #endif
84