1 //////////////////////////////////////////////////////////////////////////////
2 //
3 // (C) Copyright Ion Gaztanaga 2008-2013. Distributed under the Boost
4 // Software License, Version 1.0. (See accompanying file
5 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6 //
7 // See http://www.boost.org/libs/container for documentation.
8 //
9 //////////////////////////////////////////////////////////////////////////////
10
11 #ifndef BOOST_CONTAINER_DETAIL_VARIADIC_TEMPLATES_TOOLS_HPP
12 #define BOOST_CONTAINER_DETAIL_VARIADIC_TEMPLATES_TOOLS_HPP
13
14 #ifndef BOOST_CONFIG_HPP
15 # include <boost/config.hpp>
16 #endif
17
18 #if defined(BOOST_HAS_PRAGMA_ONCE)
19 # pragma once
20 #endif
21
22 #include <boost/container/detail/config_begin.hpp>
23 #include <boost/container/detail/workaround.hpp>
24
25 #include <boost/container/detail/type_traits.hpp>
26 #include <cstddef> //std::size_t
27
28 namespace boost {
29 namespace container {
30 namespace container_detail {
31
32 template<typename... Values>
33 class tuple;
34
35 template<> class tuple<>
36 {};
37
38 template<typename Head, typename... Tail>
39 class tuple<Head, Tail...>
40 : private tuple<Tail...>
41 {
42 typedef tuple<Tail...> inherited;
43
44 public:
tuple()45 tuple() { }
46
47 // implicit copy-constructor is okay
48 // Construct tuple from separate arguments.
tuple(typename add_const_reference<Head>::type v,typename add_const_reference<Tail>::type...vtail)49 tuple(typename add_const_reference<Head>::type v,
50 typename add_const_reference<Tail>::type... vtail)
51 : inherited(vtail...), m_head(v)
52 {}
53
54 // Construct tuple from another tuple.
55 template<typename... VValues>
tuple(const tuple<VValues...> & other)56 tuple(const tuple<VValues...>& other)
57 : m_head(other.head()), inherited(other.tail())
58 {}
59
60 template<typename... VValues>
operator =(const tuple<VValues...> & other)61 tuple& operator=(const tuple<VValues...>& other)
62 {
63 m_head = other.head();
64 tail() = other.tail();
65 return this;
66 }
67
head()68 typename add_reference<Head>::type head() { return m_head; }
head() const69 typename add_reference<const Head>::type head() const { return m_head; }
70
tail()71 inherited& tail() { return *this; }
tail() const72 const inherited& tail() const { return *this; }
73
74 protected:
75 Head m_head;
76 };
77
78
79 template<typename... Values>
tie_forward(Values &&...values)80 tuple<Values&&...> tie_forward(Values&&... values)
81 { return tuple<Values&&...>(values...); }
82
83 template<int I, typename Tuple>
84 struct tuple_element;
85
86 template<int I, typename Head, typename... Tail>
87 struct tuple_element<I, tuple<Head, Tail...> >
88 {
89 typedef typename tuple_element<I-1, tuple<Tail...> >::type type;
90 };
91
92 template<typename Head, typename... Tail>
93 struct tuple_element<0, tuple<Head, Tail...> >
94 {
95 typedef Head type;
96 };
97
98 template<int I, typename Tuple>
99 class get_impl;
100
101 template<int I, typename Head, typename... Values>
102 class get_impl<I, tuple<Head, Values...> >
103 {
104 typedef typename tuple_element<I-1, tuple<Values...> >::type Element;
105 typedef get_impl<I-1, tuple<Values...> > Next;
106
107 public:
108 typedef typename add_reference<Element>::type type;
109 typedef typename add_const_reference<Element>::type const_type;
get(tuple<Head,Values...> & t)110 static type get(tuple<Head, Values...>& t) { return Next::get(t.tail()); }
get(const tuple<Head,Values...> & t)111 static const_type get(const tuple<Head, Values...>& t) { return Next::get(t.tail()); }
112 };
113
114 template<typename Head, typename... Values>
115 class get_impl<0, tuple<Head, Values...> >
116 {
117 public:
118 typedef typename add_reference<Head>::type type;
119 typedef typename add_const_reference<Head>::type const_type;
get(tuple<Head,Values...> & t)120 static type get(tuple<Head, Values...>& t) { return t.head(); }
get(const tuple<Head,Values...> & t)121 static const_type get(const tuple<Head, Values...>& t){ return t.head(); }
122 };
123
124 template<int I, typename... Values>
get(tuple<Values...> & t)125 typename get_impl<I, tuple<Values...> >::type get(tuple<Values...>& t)
126 { return get_impl<I, tuple<Values...> >::get(t); }
127
128 template<int I, typename... Values>
get(const tuple<Values...> & t)129 typename get_impl<I, tuple<Values...> >::const_type get(const tuple<Values...>& t)
130 { return get_impl<I, tuple<Values...> >::get(t); }
131
132 ////////////////////////////////////////////////////
133 // Builds an index_tuple<0, 1, 2, ..., Num-1>, that will
134 // be used to "unpack" into comma-separated values
135 // in a function call.
136 ////////////////////////////////////////////////////
137
138 template<int... Indexes>
139 struct index_tuple{};
140
141 template<std::size_t Num, typename Tuple = index_tuple<> >
142 struct build_number_seq;
143
144 template<std::size_t Num, int... Indexes>
145 struct build_number_seq<Num, index_tuple<Indexes...> >
146 : build_number_seq<Num - 1, index_tuple<Indexes..., sizeof...(Indexes)> >
147 {};
148
149 template<int... Indexes>
150 struct build_number_seq<0, index_tuple<Indexes...> >
151 { typedef index_tuple<Indexes...> type; };
152
153
154 }}} //namespace boost { namespace container { namespace container_detail {
155
156 #include <boost/container/detail/config_end.hpp>
157
158 #endif //#ifndef BOOST_CONTAINER_DETAIL_VARIADIC_TEMPLATES_TOOLS_HPP
159