1 //  tuple_basic.hpp -----------------------------------------------------
2 
3 // Copyright (C) 1999, 2000 Jaakko Jarvi (jaakko.jarvi@cs.utu.fi)
4 //
5 // Distributed under the Boost Software License, Version 1.0. (See
6 // accompanying file LICENSE_1_0.txt or copy at
7 // http://www.boost.org/LICENSE_1_0.txt)
8 
9 // For more information, see http://www.boost.org
10 
11 // Outside help:
12 // This and that, Gary Powell.
13 // Fixed return types for get_head/get_tail
14 // ( and other bugs ) per suggestion of Jens Maurer
15 // simplified element type accessors + bug fix  (Jeremy Siek)
16 // Several changes/additions according to suggestions by Douglas Gregor,
17 // William Kempf, Vesa Karvonen, John Max Skaller, Ed Brey, Beman Dawes,
18 // David Abrahams.
19 
20 // Revision history:
21 // 2002 05 01 Hugo Duncan: Fix for Borland after Jaakko's previous changes
22 // 2002 04 18 Jaakko: tuple element types can be void or plain function
23 //                    types, as long as no object is created.
24 //                    Tuple objects can no hold even noncopyable types
25 //                    such as arrays.
26 // 2001 10 22 John Maddock
27 //      Fixes for Borland C++
28 // 2001 08 30 David Abrahams
29 //      Added default constructor for cons<>.
30 // -----------------------------------------------------------------
31 
32 #ifndef BOOST_TUPLE_BASIC_HPP
33 #define BOOST_TUPLE_BASIC_HPP
34 
35 
36 #include <utility> // needed for the assignment from pair to tuple
37 
38 #include <boost/type_traits/cv_traits.hpp>
39 #include <boost/type_traits/function_traits.hpp>
40 #include <boost/type_traits/integral_constant.hpp>
41 #include <boost/utility/swap.hpp>
42 
43 #include <boost/detail/workaround.hpp> // needed for BOOST_WORKAROUND
44 
45 #if defined(BOOST_GCC) && (BOOST_GCC >= 40700)
46 #pragma GCC diagnostic push
47 //#pragma GCC diagnostic ignored "-Wunused-local-typedefs"
48 #endif
49 
50 namespace boost {
51 namespace tuples {
52 
53 // -- null_type --------------------------------------------------------
54 struct null_type {};
55 
56 // a helper function to provide a const null_type type temporary
57 namespace detail {
cnull()58   inline const null_type cnull() { return null_type(); }
59 
60 
61 // -- if construct ------------------------------------------------
62 // Proposed by Krzysztof Czarnecki and Ulrich Eisenecker
63 
64 template <bool If, class Then, class Else> struct IF { typedef Then RET; };
65 
66 template <class Then, class Else> struct IF<false, Then, Else> {
67   typedef Else RET;
68 };
69 
70 } // end detail
71 
72 // - cons forward declaration -----------------------------------------------
73 template <class HT, class TT> struct cons;
74 
75 
76 // - tuple forward declaration -----------------------------------------------
77 template <
78   class T0 = null_type, class T1 = null_type, class T2 = null_type,
79   class T3 = null_type, class T4 = null_type, class T5 = null_type,
80   class T6 = null_type, class T7 = null_type, class T8 = null_type,
81   class T9 = null_type>
82 class tuple;
83 
84 // tuple_length forward declaration
85 template<class T> struct length;
86 
87 
88 
89 namespace detail {
90 
91 // -- generate error template, referencing to non-existing members of this
92 // template is used to produce compilation errors intentionally
93 template<class T>
94 class generate_error;
95 
96 template<int N>
97 struct drop_front {
98     template<class Tuple>
99     struct apply {
100         typedef BOOST_DEDUCED_TYPENAME drop_front<N-1>::BOOST_NESTED_TEMPLATE
101             apply<Tuple> next;
102         typedef BOOST_DEDUCED_TYPENAME next::type::tail_type type;
callboost::tuples::detail::drop_front::apply103         static const type& call(const Tuple& tup) {
104             return next::call(tup).tail;
105         }
106     };
107 };
108 
109 template<>
110 struct drop_front<0> {
111     template<class Tuple>
112     struct apply {
113         typedef Tuple type;
callboost::tuples::detail::drop_front::apply114         static const type& call(const Tuple& tup) {
115             return tup;
116         }
117     };
118 };
119 
120 } // end of namespace detail
121 
122 
123 // -cons type accessors ----------------------------------------
124 // typename tuples::element<N,T>::type gets the type of the
125 // Nth element ot T, first element is at index 0
126 // -------------------------------------------------------
127 
128 #ifndef BOOST_NO_CV_SPECIALIZATIONS
129 
130 template<int N, class T>
131 struct element
132 {
133   typedef BOOST_DEDUCED_TYPENAME detail::drop_front<N>::BOOST_NESTED_TEMPLATE
134       apply<T>::type::head_type type;
135 };
136 
137 template<int N, class T>
138 struct element<N, const T>
139 {
140 private:
141   typedef BOOST_DEDUCED_TYPENAME detail::drop_front<N>::BOOST_NESTED_TEMPLATE
142       apply<T>::type::head_type unqualified_type;
143 public:
144 #if BOOST_WORKAROUND(BOOST_BORLANDC,<0x600)
145   typedef const unqualified_type type;
146 #else
147   typedef BOOST_DEDUCED_TYPENAME boost::add_const<unqualified_type>::type type;
148 #endif
149 };
150 #else // def BOOST_NO_CV_SPECIALIZATIONS
151 
152 namespace detail {
153 
154 template<int N, class T, bool IsConst>
155 struct element_impl
156 {
157   typedef BOOST_DEDUCED_TYPENAME detail::drop_front<N>::BOOST_NESTED_TEMPLATE
158       apply<T>::type::head_type type;
159 };
160 
161 template<int N, class T>
162 struct element_impl<N, T, true /* IsConst */>
163 {
164   typedef BOOST_DEDUCED_TYPENAME detail::drop_front<N>::BOOST_NESTED_TEMPLATE
165       apply<T>::type::head_type unqualified_type;
166   typedef const unqualified_type type;
167 };
168 
169 } // end of namespace detail
170 
171 
172 template<int N, class T>
173 struct element:
174   public detail::element_impl<N, T, ::boost::is_const<T>::value>
175 {
176 };
177 
178 #endif
179 
180 
181 // -get function templates -----------------------------------------------
182 // Usage: get<N>(aTuple)
183 
184 // -- some traits classes for get functions
185 
186 // access traits lifted from detail namespace to be part of the interface,
187 // (Joel de Guzman's suggestion). Rationale: get functions are part of the
188 // interface, so should the way to express their return types be.
189 
190 template <class T> struct access_traits {
191   typedef const T& const_type;
192   typedef T& non_const_type;
193 
194   typedef const typename boost::remove_cv<T>::type& parameter_type;
195 
196 // used as the tuple constructors parameter types
197 // Rationale: non-reference tuple element types can be cv-qualified.
198 // It should be possible to initialize such types with temporaries,
199 // and when binding temporaries to references, the reference must
200 // be non-volatile and const. 8.5.3. (5)
201 };
202 
203 template <class T> struct access_traits<T&> {
204 
205   typedef T& const_type;
206   typedef T& non_const_type;
207 
208   typedef T& parameter_type;
209 };
210 
211 // get function for non-const cons-lists, returns a reference to the element
212 
213 template<int N, class HT, class TT>
214 inline typename access_traits<
215                   typename element<N, cons<HT, TT> >::type
216                 >::non_const_type
get(cons<HT,TT> & c)217 get(cons<HT, TT>& c) {
218   typedef BOOST_DEDUCED_TYPENAME detail::drop_front<N>::BOOST_NESTED_TEMPLATE
219       apply<cons<HT, TT> > impl;
220   typedef BOOST_DEDUCED_TYPENAME impl::type cons_element;
221   return const_cast<cons_element&>(impl::call(c)).head;
222 }
223 
224 // get function for const cons-lists, returns a const reference to
225 // the element. If the element is a reference, returns the reference
226 // as such (that is, can return a non-const reference)
227 template<int N, class HT, class TT>
228 inline typename access_traits<
229                   typename element<N, cons<HT, TT> >::type
230                 >::const_type
get(const cons<HT,TT> & c)231 get(const cons<HT, TT>& c) {
232   typedef BOOST_DEDUCED_TYPENAME detail::drop_front<N>::BOOST_NESTED_TEMPLATE
233       apply<cons<HT, TT> > impl;
234   return impl::call(c).head;
235 }
236 
237 // -- the cons template  --------------------------------------------------
238 namespace detail {
239 
240 //  These helper templates wrap void types and plain function types.
241 //  The reationale is to allow one to write tuple types with those types
242 //  as elements, even though it is not possible to instantiate such object.
243 //  E.g: typedef tuple<void> some_type; // ok
244 //  but: some_type x; // fails
245 
246 template <class T> class non_storeable_type {
247   non_storeable_type();
248 };
249 
250 template <class T> struct wrap_non_storeable_type {
251   typedef typename IF<
252     ::boost::is_function<T>::value, non_storeable_type<T>, T
253   >::RET type;
254 };
255 template <> struct wrap_non_storeable_type<void> {
256   typedef non_storeable_type<void> type;
257 };
258 
259 } // detail
260 
261 template <class HT, class TT>
262 struct cons {
263 
264   typedef HT head_type;
265   typedef TT tail_type;
266 
267   typedef typename
268     detail::wrap_non_storeable_type<head_type>::type stored_head_type;
269 
270   stored_head_type head;
271   tail_type tail;
272 
273   typename access_traits<stored_head_type>::non_const_type
get_headboost::tuples::cons274   get_head() { return head; }
275 
276   typename access_traits<tail_type>::non_const_type
get_tailboost::tuples::cons277   get_tail() { return tail; }
278 
279   typename access_traits<stored_head_type>::const_type
get_headboost::tuples::cons280   get_head() const { return head; }
281 
282   typename access_traits<tail_type>::const_type
get_tailboost::tuples::cons283   get_tail() const { return tail; }
284 
consboost::tuples::cons285   cons() : head(), tail() {}
286   //  cons() : head(detail::default_arg<HT>::f()), tail() {}
287 
288   // the argument for head is not strictly needed, but it prevents
289   // array type elements. This is good, since array type elements
290   // cannot be supported properly in any case (no assignment,
291   // copy works only if the tails are exactly the same type, ...)
292 
consboost::tuples::cons293   cons(typename access_traits<stored_head_type>::parameter_type h,
294        const tail_type& t)
295     : head (h), tail(t) {}
296 
297   template <class T1, class T2, class T3, class T4, class T5,
298             class T6, class T7, class T8, class T9, class T10>
consboost::tuples::cons299   cons( T1& t1, T2& t2, T3& t3, T4& t4, T5& t5,
300         T6& t6, T7& t7, T8& t8, T9& t9, T10& t10 )
301     : head (t1),
302       tail (t2, t3, t4, t5, t6, t7, t8, t9, t10, detail::cnull())
303       {}
304 
305   template <class T2, class T3, class T4, class T5,
306             class T6, class T7, class T8, class T9, class T10>
consboost::tuples::cons307   cons( const null_type& /*t1*/, T2& t2, T3& t3, T4& t4, T5& t5,
308         T6& t6, T7& t7, T8& t8, T9& t9, T10& t10 )
309     : head (),
310       tail (t2, t3, t4, t5, t6, t7, t8, t9, t10, detail::cnull())
311       {}
312 
consboost::tuples::cons313   cons( const cons& u ) : head(u.head), tail(u.tail) {}
314 
315   template <class HT2, class TT2>
consboost::tuples::cons316   cons( const cons<HT2, TT2>& u ) : head(u.head), tail(u.tail) {}
317 
318   template <class HT2, class TT2>
operator =boost::tuples::cons319   cons& operator=( const cons<HT2, TT2>& u ) {
320     head=u.head; tail=u.tail; return *this;
321   }
322 
323   // must define assignment operator explicitly, implicit version is
324   // illformed if HT is a reference (12.8. (12))
operator =boost::tuples::cons325   cons& operator=(const cons& u) {
326     head = u.head; tail = u.tail;  return *this;
327   }
328 
329   template <class T1, class T2>
operator =boost::tuples::cons330   cons& operator=( const std::pair<T1, T2>& u ) {
331     BOOST_STATIC_ASSERT(length<cons>::value == 2); // check length = 2
332     head = u.first; tail.head = u.second; return *this;
333   }
334 
335   // get member functions (non-const and const)
336   template <int N>
337   typename access_traits<
338              typename element<N, cons<HT, TT> >::type
339            >::non_const_type
getboost::tuples::cons340   get() {
341     return boost::tuples::get<N>(*this); // delegate to non-member get
342   }
343 
344   template <int N>
345   typename access_traits<
346              typename element<N, cons<HT, TT> >::type
347            >::const_type
getboost::tuples::cons348   get() const {
349     return boost::tuples::get<N>(*this); // delegate to non-member get
350   }
351 };
352 
353 template <class HT>
354 struct cons<HT, null_type> {
355 
356   typedef HT head_type;
357   typedef null_type tail_type;
358   typedef cons<HT, null_type> self_type;
359 
360   typedef typename
361     detail::wrap_non_storeable_type<head_type>::type stored_head_type;
362   stored_head_type head;
363 
364   typename access_traits<stored_head_type>::non_const_type
get_headboost::tuples::cons365   get_head() { return head; }
366 
get_tailboost::tuples::cons367   null_type get_tail() { return null_type(); }
368 
369   typename access_traits<stored_head_type>::const_type
get_headboost::tuples::cons370   get_head() const { return head; }
371 
get_tailboost::tuples::cons372   const null_type get_tail() const { return null_type(); }
373 
374   //  cons() : head(detail::default_arg<HT>::f()) {}
consboost::tuples::cons375   cons() : head() {}
376 
consboost::tuples::cons377   cons(typename access_traits<stored_head_type>::parameter_type h,
378        const null_type& = null_type())
379     : head (h) {}
380 
381   template<class T1>
consboost::tuples::cons382   cons(T1& t1, const null_type&, const null_type&, const null_type&,
383        const null_type&, const null_type&, const null_type&,
384        const null_type&, const null_type&, const null_type&)
385   : head (t1) {}
386 
consboost::tuples::cons387   cons(const null_type&,
388        const null_type&, const null_type&, const null_type&,
389        const null_type&, const null_type&, const null_type&,
390        const null_type&, const null_type&, const null_type&)
391   : head () {}
392 
consboost::tuples::cons393   cons( const cons& u ) : head(u.head) {}
394 
395   template <class HT2>
consboost::tuples::cons396   cons( const cons<HT2, null_type>& u ) : head(u.head) {}
397 
398   template <class HT2>
operator =boost::tuples::cons399   cons& operator=(const cons<HT2, null_type>& u )
400   { head = u.head; return *this; }
401 
402   // must define assignment operator explicitely, implicit version
403   // is illformed if HT is a reference
operator =boost::tuples::cons404   cons& operator=(const cons& u) { head = u.head; return *this; }
405 
406   template <int N>
407   typename access_traits<
408              typename element<N, self_type>::type
409             >::non_const_type
getboost::tuples::cons410   get() {
411     return boost::tuples::get<N>(*this);
412   }
413 
414   template <int N>
415   typename access_traits<
416              typename element<N, self_type>::type
417            >::const_type
getboost::tuples::cons418   get() const {
419     return boost::tuples::get<N>(*this);
420   }
421 
422 };
423 
424 // templates for finding out the length of the tuple -------------------
425 
426 template<class T>
427 struct length: boost::integral_constant<int, 1 + length<typename T::tail_type>::value>
428 {
429 };
430 
431 template<>
432 struct length<tuple<> >: boost::integral_constant<int, 0>
433 {
434 };
435 
436 template<>
437 struct length<tuple<> const>: boost::integral_constant<int, 0>
438 {
439 };
440 
441 template<>
442 struct length<null_type>: boost::integral_constant<int, 0>
443 {
444 };
445 
446 template<>
447 struct length<null_type const>: boost::integral_constant<int, 0>
448 {
449 };
450 
451 namespace detail {
452 
453 // Tuple to cons mapper --------------------------------------------------
454 template <class T0, class T1, class T2, class T3, class T4,
455           class T5, class T6, class T7, class T8, class T9>
456 struct map_tuple_to_cons
457 {
458   typedef cons<T0,
459                typename map_tuple_to_cons<T1, T2, T3, T4, T5,
460                                           T6, T7, T8, T9, null_type>::type
461               > type;
462 };
463 
464 // The empty tuple is a null_type
465 template <>
466 struct map_tuple_to_cons<null_type, null_type, null_type, null_type, null_type, null_type, null_type, null_type, null_type, null_type>
467 {
468   typedef null_type type;
469 };
470 
471 } // end detail
472 
473 // -------------------------------------------------------------------
474 // -- tuple ------------------------------------------------------
475 template <class T0, class T1, class T2, class T3, class T4,
476           class T5, class T6, class T7, class T8, class T9>
477 
478 class tuple :
479   public detail::map_tuple_to_cons<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>::type
480 {
481 public:
482   typedef typename
483     detail::map_tuple_to_cons<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>::type inherited;
484   typedef typename inherited::head_type head_type;
485   typedef typename inherited::tail_type tail_type;
486 
487 
488 // access_traits<T>::parameter_type takes non-reference types as const T&
tuple()489   tuple() {}
490 
tuple(typename access_traits<T0>::parameter_type t0)491   explicit tuple(typename access_traits<T0>::parameter_type t0)
492     : inherited(t0, detail::cnull(), detail::cnull(), detail::cnull(),
493                 detail::cnull(), detail::cnull(), detail::cnull(),
494                 detail::cnull(), detail::cnull(), detail::cnull()) {}
495 
tuple(typename access_traits<T0>::parameter_type t0,typename access_traits<T1>::parameter_type t1)496   tuple(typename access_traits<T0>::parameter_type t0,
497         typename access_traits<T1>::parameter_type t1)
498     : inherited(t0, t1, detail::cnull(), detail::cnull(),
499                 detail::cnull(), detail::cnull(), detail::cnull(),
500                 detail::cnull(), detail::cnull(), detail::cnull()) {}
501 
tuple(typename access_traits<T0>::parameter_type t0,typename access_traits<T1>::parameter_type t1,typename access_traits<T2>::parameter_type t2)502   tuple(typename access_traits<T0>::parameter_type t0,
503         typename access_traits<T1>::parameter_type t1,
504         typename access_traits<T2>::parameter_type t2)
505     : inherited(t0, t1, t2, detail::cnull(), detail::cnull(),
506                 detail::cnull(), detail::cnull(), detail::cnull(),
507                 detail::cnull(), detail::cnull()) {}
508 
tuple(typename access_traits<T0>::parameter_type t0,typename access_traits<T1>::parameter_type t1,typename access_traits<T2>::parameter_type t2,typename access_traits<T3>::parameter_type t3)509   tuple(typename access_traits<T0>::parameter_type t0,
510         typename access_traits<T1>::parameter_type t1,
511         typename access_traits<T2>::parameter_type t2,
512         typename access_traits<T3>::parameter_type t3)
513     : inherited(t0, t1, t2, t3, detail::cnull(), detail::cnull(),
514                 detail::cnull(), detail::cnull(), detail::cnull(),
515                 detail::cnull()) {}
516 
tuple(typename access_traits<T0>::parameter_type t0,typename access_traits<T1>::parameter_type t1,typename access_traits<T2>::parameter_type t2,typename access_traits<T3>::parameter_type t3,typename access_traits<T4>::parameter_type t4)517   tuple(typename access_traits<T0>::parameter_type t0,
518         typename access_traits<T1>::parameter_type t1,
519         typename access_traits<T2>::parameter_type t2,
520         typename access_traits<T3>::parameter_type t3,
521         typename access_traits<T4>::parameter_type t4)
522     : inherited(t0, t1, t2, t3, t4, detail::cnull(), detail::cnull(),
523                 detail::cnull(), detail::cnull(), detail::cnull()) {}
524 
tuple(typename access_traits<T0>::parameter_type t0,typename access_traits<T1>::parameter_type t1,typename access_traits<T2>::parameter_type t2,typename access_traits<T3>::parameter_type t3,typename access_traits<T4>::parameter_type t4,typename access_traits<T5>::parameter_type t5)525   tuple(typename access_traits<T0>::parameter_type t0,
526         typename access_traits<T1>::parameter_type t1,
527         typename access_traits<T2>::parameter_type t2,
528         typename access_traits<T3>::parameter_type t3,
529         typename access_traits<T4>::parameter_type t4,
530         typename access_traits<T5>::parameter_type t5)
531     : inherited(t0, t1, t2, t3, t4, t5, detail::cnull(), detail::cnull(),
532                 detail::cnull(), detail::cnull()) {}
533 
tuple(typename access_traits<T0>::parameter_type t0,typename access_traits<T1>::parameter_type t1,typename access_traits<T2>::parameter_type t2,typename access_traits<T3>::parameter_type t3,typename access_traits<T4>::parameter_type t4,typename access_traits<T5>::parameter_type t5,typename access_traits<T6>::parameter_type t6)534   tuple(typename access_traits<T0>::parameter_type t0,
535         typename access_traits<T1>::parameter_type t1,
536         typename access_traits<T2>::parameter_type t2,
537         typename access_traits<T3>::parameter_type t3,
538         typename access_traits<T4>::parameter_type t4,
539         typename access_traits<T5>::parameter_type t5,
540         typename access_traits<T6>::parameter_type t6)
541     : inherited(t0, t1, t2, t3, t4, t5, t6, detail::cnull(),
542                 detail::cnull(), detail::cnull()) {}
543 
tuple(typename access_traits<T0>::parameter_type t0,typename access_traits<T1>::parameter_type t1,typename access_traits<T2>::parameter_type t2,typename access_traits<T3>::parameter_type t3,typename access_traits<T4>::parameter_type t4,typename access_traits<T5>::parameter_type t5,typename access_traits<T6>::parameter_type t6,typename access_traits<T7>::parameter_type t7)544   tuple(typename access_traits<T0>::parameter_type t0,
545         typename access_traits<T1>::parameter_type t1,
546         typename access_traits<T2>::parameter_type t2,
547         typename access_traits<T3>::parameter_type t3,
548         typename access_traits<T4>::parameter_type t4,
549         typename access_traits<T5>::parameter_type t5,
550         typename access_traits<T6>::parameter_type t6,
551         typename access_traits<T7>::parameter_type t7)
552     : inherited(t0, t1, t2, t3, t4, t5, t6, t7, detail::cnull(),
553                 detail::cnull()) {}
554 
tuple(typename access_traits<T0>::parameter_type t0,typename access_traits<T1>::parameter_type t1,typename access_traits<T2>::parameter_type t2,typename access_traits<T3>::parameter_type t3,typename access_traits<T4>::parameter_type t4,typename access_traits<T5>::parameter_type t5,typename access_traits<T6>::parameter_type t6,typename access_traits<T7>::parameter_type t7,typename access_traits<T8>::parameter_type t8)555   tuple(typename access_traits<T0>::parameter_type t0,
556         typename access_traits<T1>::parameter_type t1,
557         typename access_traits<T2>::parameter_type t2,
558         typename access_traits<T3>::parameter_type t3,
559         typename access_traits<T4>::parameter_type t4,
560         typename access_traits<T5>::parameter_type t5,
561         typename access_traits<T6>::parameter_type t6,
562         typename access_traits<T7>::parameter_type t7,
563         typename access_traits<T8>::parameter_type t8)
564     : inherited(t0, t1, t2, t3, t4, t5, t6, t7, t8, detail::cnull()) {}
565 
tuple(typename access_traits<T0>::parameter_type t0,typename access_traits<T1>::parameter_type t1,typename access_traits<T2>::parameter_type t2,typename access_traits<T3>::parameter_type t3,typename access_traits<T4>::parameter_type t4,typename access_traits<T5>::parameter_type t5,typename access_traits<T6>::parameter_type t6,typename access_traits<T7>::parameter_type t7,typename access_traits<T8>::parameter_type t8,typename access_traits<T9>::parameter_type t9)566   tuple(typename access_traits<T0>::parameter_type t0,
567         typename access_traits<T1>::parameter_type t1,
568         typename access_traits<T2>::parameter_type t2,
569         typename access_traits<T3>::parameter_type t3,
570         typename access_traits<T4>::parameter_type t4,
571         typename access_traits<T5>::parameter_type t5,
572         typename access_traits<T6>::parameter_type t6,
573         typename access_traits<T7>::parameter_type t7,
574         typename access_traits<T8>::parameter_type t8,
575         typename access_traits<T9>::parameter_type t9)
576     : inherited(t0, t1, t2, t3, t4, t5, t6, t7, t8, t9) {}
577 
578 
579   template<class U1, class U2>
tuple(const cons<U1,U2> & p)580   tuple(const cons<U1, U2>& p) : inherited(p) {}
581 
582   template <class U1, class U2>
operator =(const cons<U1,U2> & k)583   tuple& operator=(const cons<U1, U2>& k) {
584     inherited::operator=(k);
585     return *this;
586   }
587 
588   template <class U1, class U2>
operator =(const std::pair<U1,U2> & k)589   tuple& operator=(const std::pair<U1, U2>& k) {
590     BOOST_STATIC_ASSERT(length<tuple>::value == 2);// check_length = 2
591     this->head = k.first;
592     this->tail.head = k.second;
593     return *this;
594   }
595 
596 };
597 
598 // The empty tuple
599 template <>
600 class tuple<null_type, null_type, null_type, null_type, null_type, null_type, null_type, null_type, null_type, null_type>  :
601   public null_type
602 {
603 public:
604   typedef null_type inherited;
605 };
606 
607 
608 // Swallows any assignment   (by Doug Gregor)
609 namespace detail {
610 
611 struct swallow_assign;
612 typedef void (detail::swallow_assign::*ignore_t)();
613 struct swallow_assign {
swallow_assignboost::tuples::detail::swallow_assign614   swallow_assign(ignore_t(*)(ignore_t)) {}
615   template<typename T>
operator =boost::tuples::detail::swallow_assign616   swallow_assign const& operator=(const T&) const {
617     return *this;
618   }
619 };
620 
621 
622 } // namespace detail
623 
624 // "ignore" allows tuple positions to be ignored when using "tie".
ignore(detail::ignore_t)625 inline detail::ignore_t ignore(detail::ignore_t) { return 0; }
626 
627 // ---------------------------------------------------------------------------
628 // The call_traits for make_tuple
629 // Honours the reference_wrapper class.
630 
631 // Must be instantiated with plain or const plain types (not with references)
632 
633 // from template<class T> foo(const T& t) : make_tuple_traits<const T>::type
634 // from template<class T> foo(T& t) : make_tuple_traits<T>::type
635 
636 // Conversions:
637 // T -> T,
638 // references -> compile_time_error
639 // reference_wrapper<T> -> T&
640 // const reference_wrapper<T> -> T&
641 // array -> const ref array
642 
643 
644 template<class T>
645 struct make_tuple_traits {
646   typedef T type;
647 
648   // commented away, see below  (JJ)
649   //  typedef typename IF<
650   //  boost::is_function<T>::value,
651   //  T&,
652   //  T>::RET type;
653 
654 };
655 
656 // The is_function test was there originally for plain function types,
657 // which can't be stored as such (we must either store them as references or
658 // pointers). Such a type could be formed if make_tuple was called with a
659 // reference to a function.
660 // But this would mean that a const qualified function type was formed in
661 // the make_tuple function and hence make_tuple can't take a function
662 // reference as a parameter, and thus T can't be a function type.
663 // So is_function test was removed.
664 // (14.8.3. says that type deduction fails if a cv-qualified function type
665 // is created. (It only applies for the case of explicitly specifying template
666 // args, though?)) (JJ)
667 
668 template<class T>
669 struct make_tuple_traits<T&> {
670   typedef typename
671      detail::generate_error<T&>::
672        do_not_use_with_reference_type error;
673 };
674 
675 // Arrays can't be stored as plain types; convert them to references.
676 // All arrays are converted to const. This is because make_tuple takes its
677 // parameters as const T& and thus the knowledge of the potential
678 // non-constness of actual argument is lost.
679 template<class T, int n>  struct make_tuple_traits <T[n]> {
680   typedef const T (&type)[n];
681 };
682 
683 template<class T, int n>
684 struct make_tuple_traits<const T[n]> {
685   typedef const T (&type)[n];
686 };
687 
688 template<class T, int n>  struct make_tuple_traits<volatile T[n]> {
689   typedef const volatile T (&type)[n];
690 };
691 
692 template<class T, int n>
693 struct make_tuple_traits<const volatile T[n]> {
694   typedef const volatile T (&type)[n];
695 };
696 
697 template<class T>
698 struct make_tuple_traits<reference_wrapper<T> >{
699   typedef T& type;
700 };
701 
702 template<class T>
703 struct make_tuple_traits<const reference_wrapper<T> >{
704   typedef T& type;
705 };
706 
707 template<>
708 struct make_tuple_traits<detail::ignore_t(detail::ignore_t)> {
709   typedef detail::swallow_assign type;
710 };
711 
712 
713 
714 namespace detail {
715 
716 // a helper traits to make the make_tuple functions shorter (Vesa Karvonen's
717 // suggestion)
718 template <
719   class T0 = null_type, class T1 = null_type, class T2 = null_type,
720   class T3 = null_type, class T4 = null_type, class T5 = null_type,
721   class T6 = null_type, class T7 = null_type, class T8 = null_type,
722   class T9 = null_type
723 >
724 struct make_tuple_mapper {
725   typedef
726     tuple<typename make_tuple_traits<T0>::type,
727           typename make_tuple_traits<T1>::type,
728           typename make_tuple_traits<T2>::type,
729           typename make_tuple_traits<T3>::type,
730           typename make_tuple_traits<T4>::type,
731           typename make_tuple_traits<T5>::type,
732           typename make_tuple_traits<T6>::type,
733           typename make_tuple_traits<T7>::type,
734           typename make_tuple_traits<T8>::type,
735           typename make_tuple_traits<T9>::type> type;
736 };
737 
738 } // end detail
739 
740 // -make_tuple function templates -----------------------------------
make_tuple()741 inline tuple<> make_tuple() {
742   return tuple<>();
743 }
744 
745 template<class T0>
746 inline typename detail::make_tuple_mapper<T0>::type
make_tuple(const T0 & t0)747 make_tuple(const T0& t0) {
748   typedef typename detail::make_tuple_mapper<T0>::type t;
749   return t(t0);
750 }
751 
752 template<class T0, class T1>
753 inline typename detail::make_tuple_mapper<T0, T1>::type
make_tuple(const T0 & t0,const T1 & t1)754 make_tuple(const T0& t0, const T1& t1) {
755   typedef typename detail::make_tuple_mapper<T0, T1>::type t;
756   return t(t0, t1);
757 }
758 
759 template<class T0, class T1, class T2>
760 inline typename detail::make_tuple_mapper<T0, T1, T2>::type
make_tuple(const T0 & t0,const T1 & t1,const T2 & t2)761 make_tuple(const T0& t0, const T1& t1, const T2& t2) {
762   typedef typename detail::make_tuple_mapper<T0, T1, T2>::type t;
763   return t(t0, t1, t2);
764 }
765 
766 template<class T0, class T1, class T2, class T3>
767 inline typename detail::make_tuple_mapper<T0, T1, T2, T3>::type
make_tuple(const T0 & t0,const T1 & t1,const T2 & t2,const T3 & t3)768 make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3) {
769   typedef typename detail::make_tuple_mapper<T0, T1, T2, T3>::type t;
770   return t(t0, t1, t2, t3);
771 }
772 
773 template<class T0, class T1, class T2, class T3, class T4>
774 inline typename detail::make_tuple_mapper<T0, T1, T2, T3, T4>::type
make_tuple(const T0 & t0,const T1 & t1,const T2 & t2,const T3 & t3,const T4 & t4)775 make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3,
776                   const T4& t4) {
777   typedef typename detail::make_tuple_mapper<T0, T1, T2, T3, T4>::type t;
778   return t(t0, t1, t2, t3, t4);
779 }
780 
781 template<class T0, class T1, class T2, class T3, class T4, class T5>
782 inline typename detail::make_tuple_mapper<T0, T1, T2, T3, T4, T5>::type
make_tuple(const T0 & t0,const T1 & t1,const T2 & t2,const T3 & t3,const T4 & t4,const T5 & t5)783 make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3,
784                   const T4& t4, const T5& t5) {
785   typedef typename detail::make_tuple_mapper<T0, T1, T2, T3, T4, T5>::type t;
786   return t(t0, t1, t2, t3, t4, t5);
787 }
788 
789 template<class T0, class T1, class T2, class T3, class T4, class T5, class T6>
790 inline typename detail::make_tuple_mapper<T0, T1, T2, T3, T4, T5, T6>::type
make_tuple(const T0 & t0,const T1 & t1,const T2 & t2,const T3 & t3,const T4 & t4,const T5 & t5,const T6 & t6)791 make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3,
792                   const T4& t4, const T5& t5, const T6& t6) {
793   typedef typename detail::make_tuple_mapper
794            <T0, T1, T2, T3, T4, T5, T6>::type t;
795   return t(t0, t1, t2, t3, t4, t5, t6);
796 }
797 
798 template<class T0, class T1, class T2, class T3, class T4, class T5, class T6,
799          class T7>
800 inline typename detail::make_tuple_mapper<T0, T1, T2, T3, T4, T5, T6, T7>::type
make_tuple(const T0 & t0,const T1 & t1,const T2 & t2,const T3 & t3,const T4 & t4,const T5 & t5,const T6 & t6,const T7 & t7)801 make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3,
802                   const T4& t4, const T5& t5, const T6& t6, const T7& t7) {
803   typedef typename detail::make_tuple_mapper
804            <T0, T1, T2, T3, T4, T5, T6, T7>::type t;
805   return t(t0, t1, t2, t3, t4, t5, t6, t7);
806 }
807 
808 template<class T0, class T1, class T2, class T3, class T4, class T5, class T6,
809          class T7, class T8>
810 inline typename detail::make_tuple_mapper
811   <T0, T1, T2, T3, T4, T5, T6, T7, T8>::type
make_tuple(const T0 & t0,const T1 & t1,const T2 & t2,const T3 & t3,const T4 & t4,const T5 & t5,const T6 & t6,const T7 & t7,const T8 & t8)812 make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3,
813                   const T4& t4, const T5& t5, const T6& t6, const T7& t7,
814                   const T8& t8) {
815   typedef typename detail::make_tuple_mapper
816            <T0, T1, T2, T3, T4, T5, T6, T7, T8>::type t;
817   return t(t0, t1, t2, t3, t4, t5, t6, t7, t8);
818 }
819 
820 template<class T0, class T1, class T2, class T3, class T4, class T5, class T6,
821          class T7, class T8, class T9>
822 inline typename detail::make_tuple_mapper
823   <T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>::type
make_tuple(const T0 & t0,const T1 & t1,const T2 & t2,const T3 & t3,const T4 & t4,const T5 & t5,const T6 & t6,const T7 & t7,const T8 & t8,const T9 & t9)824 make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3,
825                   const T4& t4, const T5& t5, const T6& t6, const T7& t7,
826                   const T8& t8, const T9& t9) {
827   typedef typename detail::make_tuple_mapper
828            <T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>::type t;
829   return t(t0, t1, t2, t3, t4, t5, t6, t7, t8, t9);
830 }
831 
832 namespace detail {
833 
834 template<class T>
835 struct tie_traits {
836   typedef T& type;
837 };
838 
839 template<>
840 struct tie_traits<ignore_t(ignore_t)> {
841   typedef swallow_assign type;
842 };
843 
844 template<>
845 struct tie_traits<void> {
846   typedef null_type type;
847 };
848 
849 template <
850   class T0 = void, class T1 = void, class T2 = void,
851   class T3 = void, class T4 = void, class T5 = void,
852   class T6 = void, class T7 = void, class T8 = void,
853   class T9 = void
854 >
855 struct tie_mapper {
856   typedef
857     tuple<typename tie_traits<T0>::type,
858           typename tie_traits<T1>::type,
859           typename tie_traits<T2>::type,
860           typename tie_traits<T3>::type,
861           typename tie_traits<T4>::type,
862           typename tie_traits<T5>::type,
863           typename tie_traits<T6>::type,
864           typename tie_traits<T7>::type,
865           typename tie_traits<T8>::type,
866           typename tie_traits<T9>::type> type;
867 };
868 
869 }
870 
871 // Tie function templates -------------------------------------------------
872 template<class T0>
873 inline typename detail::tie_mapper<T0>::type
tie(T0 & t0)874 tie(T0& t0) {
875   typedef typename detail::tie_mapper<T0>::type t;
876   return t(t0);
877 }
878 
879 template<class T0, class T1>
880 inline typename detail::tie_mapper<T0, T1>::type
tie(T0 & t0,T1 & t1)881 tie(T0& t0, T1& t1) {
882   typedef typename detail::tie_mapper<T0, T1>::type t;
883   return t(t0, t1);
884 }
885 
886 template<class T0, class T1, class T2>
887 inline typename detail::tie_mapper<T0, T1, T2>::type
tie(T0 & t0,T1 & t1,T2 & t2)888 tie(T0& t0, T1& t1, T2& t2) {
889   typedef typename detail::tie_mapper<T0, T1, T2>::type t;
890   return t(t0, t1, t2);
891 }
892 
893 template<class T0, class T1, class T2, class T3>
894 inline typename detail::tie_mapper<T0, T1, T2, T3>::type
tie(T0 & t0,T1 & t1,T2 & t2,T3 & t3)895 tie(T0& t0, T1& t1, T2& t2, T3& t3) {
896   typedef typename detail::tie_mapper<T0, T1, T2, T3>::type t;
897   return t(t0, t1, t2, t3);
898 }
899 
900 template<class T0, class T1, class T2, class T3, class T4>
901 inline typename detail::tie_mapper<T0, T1, T2, T3, T4>::type
tie(T0 & t0,T1 & t1,T2 & t2,T3 & t3,T4 & t4)902 tie(T0& t0, T1& t1, T2& t2, T3& t3,
903                   T4& t4) {
904   typedef typename detail::tie_mapper<T0, T1, T2, T3, T4>::type t;
905   return t(t0, t1, t2, t3, t4);
906 }
907 
908 template<class T0, class T1, class T2, class T3, class T4, class T5>
909 inline typename detail::tie_mapper<T0, T1, T2, T3, T4, T5>::type
tie(T0 & t0,T1 & t1,T2 & t2,T3 & t3,T4 & t4,T5 & t5)910 tie(T0& t0, T1& t1, T2& t2, T3& t3,
911                   T4& t4, T5& t5) {
912   typedef typename detail::tie_mapper<T0, T1, T2, T3, T4, T5>::type t;
913   return t(t0, t1, t2, t3, t4, t5);
914 }
915 
916 template<class T0, class T1, class T2, class T3, class T4, class T5, class T6>
917 inline typename detail::tie_mapper<T0, T1, T2, T3, T4, T5, T6>::type
tie(T0 & t0,T1 & t1,T2 & t2,T3 & t3,T4 & t4,T5 & t5,T6 & t6)918 tie(T0& t0, T1& t1, T2& t2, T3& t3,
919                   T4& t4, T5& t5, T6& t6) {
920   typedef typename detail::tie_mapper
921            <T0, T1, T2, T3, T4, T5, T6>::type t;
922   return t(t0, t1, t2, t3, t4, t5, t6);
923 }
924 
925 template<class T0, class T1, class T2, class T3, class T4, class T5, class T6,
926          class T7>
927 inline typename detail::tie_mapper<T0, T1, T2, T3, T4, T5, T6, T7>::type
tie(T0 & t0,T1 & t1,T2 & t2,T3 & t3,T4 & t4,T5 & t5,T6 & t6,T7 & t7)928 tie(T0& t0, T1& t1, T2& t2, T3& t3,
929                   T4& t4, T5& t5, T6& t6, T7& t7) {
930   typedef typename detail::tie_mapper
931            <T0, T1, T2, T3, T4, T5, T6, T7>::type t;
932   return t(t0, t1, t2, t3, t4, t5, t6, t7);
933 }
934 
935 template<class T0, class T1, class T2, class T3, class T4, class T5, class T6,
936          class T7, class T8>
937 inline typename detail::tie_mapper
938   <T0, T1, T2, T3, T4, T5, T6, T7, T8>::type
tie(T0 & t0,T1 & t1,T2 & t2,T3 & t3,T4 & t4,T5 & t5,T6 & t6,T7 & t7,T8 & t8)939 tie(T0& t0, T1& t1, T2& t2, T3& t3,
940                   T4& t4, T5& t5, T6& t6, T7& t7,
941                   T8& t8) {
942   typedef typename detail::tie_mapper
943            <T0, T1, T2, T3, T4, T5, T6, T7, T8>::type t;
944   return t(t0, t1, t2, t3, t4, t5, t6, t7, t8);
945 }
946 
947 template<class T0, class T1, class T2, class T3, class T4, class T5, class T6,
948          class T7, class T8, class T9>
949 inline typename detail::tie_mapper
950   <T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>::type
tie(T0 & t0,T1 & t1,T2 & t2,T3 & t3,T4 & t4,T5 & t5,T6 & t6,T7 & t7,T8 & t8,T9 & t9)951 tie(T0& t0, T1& t1, T2& t2, T3& t3,
952                   T4& t4, T5& t5, T6& t6, T7& t7,
953                   T8& t8, T9& t9) {
954   typedef typename detail::tie_mapper
955            <T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>::type t;
956   return t(t0, t1, t2, t3, t4, t5, t6, t7, t8, t9);
957 }
958 
959 template <class T0, class T1, class T2, class T3, class T4,
960           class T5, class T6, class T7, class T8, class T9>
961 void swap(tuple<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>& lhs,
962           tuple<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>& rhs);
swap(null_type &,null_type &)963 inline void swap(null_type&, null_type&) {}
964 template<class HH>
swap(cons<HH,null_type> & lhs,cons<HH,null_type> & rhs)965 inline void swap(cons<HH, null_type>& lhs, cons<HH, null_type>& rhs) {
966   ::boost::swap(lhs.head, rhs.head);
967 }
968 template<class HH, class TT>
swap(cons<HH,TT> & lhs,cons<HH,TT> & rhs)969 inline void swap(cons<HH, TT>& lhs, cons<HH, TT>& rhs) {
970   ::boost::swap(lhs.head, rhs.head);
971   ::boost::tuples::swap(lhs.tail, rhs.tail);
972 }
973 template <class T0, class T1, class T2, class T3, class T4,
974           class T5, class T6, class T7, class T8, class T9>
swap(tuple<T0,T1,T2,T3,T4,T5,T6,T7,T8,T9> & lhs,tuple<T0,T1,T2,T3,T4,T5,T6,T7,T8,T9> & rhs)975 inline void swap(tuple<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>& lhs,
976           tuple<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>& rhs) {
977   typedef tuple<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9> tuple_type;
978   typedef typename tuple_type::inherited base;
979   ::boost::tuples::swap(static_cast<base&>(lhs), static_cast<base&>(rhs));
980 }
981 
982 } // end of namespace tuples
983 } // end of namespace boost
984 
985 
986 #if defined(BOOST_GCC) && (BOOST_GCC >= 40700)
987 #pragma GCC diagnostic pop
988 #endif
989 
990 
991 #endif // BOOST_TUPLE_BASIC_HPP
992