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