tuple_basic.hpp 32 KB

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  1. // tuple_basic.hpp -----------------------------------------------------
  2. // Copyright (C) 1999, 2000 Jaakko Jarvi (jaakko.jarvi@cs.utu.fi)
  3. //
  4. // Distributed under the Boost Software License, Version 1.0. (See
  5. // accompanying file LICENSE_1_0.txt or copy at
  6. // http://www.boost.org/LICENSE_1_0.txt)
  7. // For more information, see http://www.boost.org
  8. // Outside help:
  9. // This and that, Gary Powell.
  10. // Fixed return types for get_head/get_tail
  11. // ( and other bugs ) per suggestion of Jens Maurer
  12. // simplified element type accessors + bug fix (Jeremy Siek)
  13. // Several changes/additions according to suggestions by Douglas Gregor,
  14. // William Kempf, Vesa Karvonen, John Max Skaller, Ed Brey, Beman Dawes,
  15. // David Abrahams.
  16. // Revision history:
  17. // 2002 05 01 Hugo Duncan: Fix for Borland after Jaakko's previous changes
  18. // 2002 04 18 Jaakko: tuple element types can be void or plain function
  19. // types, as long as no object is created.
  20. // Tuple objects can no hold even noncopyable types
  21. // such as arrays.
  22. // 2001 10 22 John Maddock
  23. // Fixes for Borland C++
  24. // 2001 08 30 David Abrahams
  25. // Added default constructor for cons<>.
  26. // -----------------------------------------------------------------
  27. #ifndef BOOST_TUPLE_BASIC_HPP
  28. #define BOOST_TUPLE_BASIC_HPP
  29. #include <utility> // needed for the assignment from pair to tuple
  30. #include "boost/type_traits/cv_traits.hpp"
  31. #include "boost/type_traits/function_traits.hpp"
  32. #include "boost/utility/swap.hpp"
  33. #include "boost/detail/workaround.hpp" // needed for BOOST_WORKAROUND
  34. namespace boost {
  35. namespace tuples {
  36. // -- null_type --------------------------------------------------------
  37. struct null_type {};
  38. // a helper function to provide a const null_type type temporary
  39. namespace detail {
  40. inline const null_type cnull() { return null_type(); }
  41. // -- if construct ------------------------------------------------
  42. // Proposed by Krzysztof Czarnecki and Ulrich Eisenecker
  43. template <bool If, class Then, class Else> struct IF { typedef Then RET; };
  44. template <class Then, class Else> struct IF<false, Then, Else> {
  45. typedef Else RET;
  46. };
  47. } // end detail
  48. // - cons forward declaration -----------------------------------------------
  49. template <class HT, class TT> struct cons;
  50. // - tuple forward declaration -----------------------------------------------
  51. template <
  52. class T0 = null_type, class T1 = null_type, class T2 = null_type,
  53. class T3 = null_type, class T4 = null_type, class T5 = null_type,
  54. class T6 = null_type, class T7 = null_type, class T8 = null_type,
  55. class T9 = null_type>
  56. class tuple;
  57. // tuple_length forward declaration
  58. template<class T> struct length;
  59. namespace detail {
  60. // -- generate error template, referencing to non-existing members of this
  61. // template is used to produce compilation errors intentionally
  62. template<class T>
  63. class generate_error;
  64. template<int N>
  65. struct drop_front {
  66. template<class Tuple>
  67. struct apply {
  68. typedef BOOST_DEDUCED_TYPENAME drop_front<N-1>::BOOST_NESTED_TEMPLATE
  69. apply<Tuple> next;
  70. typedef BOOST_DEDUCED_TYPENAME next::type::tail_type type;
  71. static const type& call(const Tuple& tup) {
  72. return next::call(tup).tail;
  73. }
  74. };
  75. };
  76. template<>
  77. struct drop_front<0> {
  78. template<class Tuple>
  79. struct apply {
  80. typedef Tuple type;
  81. static const type& call(const Tuple& tup) {
  82. return tup;
  83. }
  84. };
  85. };
  86. } // end of namespace detail
  87. // -cons type accessors ----------------------------------------
  88. // typename tuples::element<N,T>::type gets the type of the
  89. // Nth element ot T, first element is at index 0
  90. // -------------------------------------------------------
  91. #ifndef BOOST_NO_CV_SPECIALIZATIONS
  92. template<int N, class T>
  93. struct element
  94. {
  95. typedef BOOST_DEDUCED_TYPENAME detail::drop_front<N>::BOOST_NESTED_TEMPLATE
  96. apply<T>::type::head_type type;
  97. };
  98. template<int N, class T>
  99. struct element<N, const T>
  100. {
  101. private:
  102. typedef BOOST_DEDUCED_TYPENAME detail::drop_front<N>::BOOST_NESTED_TEMPLATE
  103. apply<T>::type::head_type unqualified_type;
  104. public:
  105. #if BOOST_WORKAROUND(__BORLANDC__,<0x600)
  106. typedef const unqualified_type type;
  107. #else
  108. typedef BOOST_DEDUCED_TYPENAME boost::add_const<unqualified_type>::type type;
  109. #endif
  110. };
  111. #else // def BOOST_NO_CV_SPECIALIZATIONS
  112. namespace detail {
  113. template<int N, class T, bool IsConst>
  114. struct element_impl
  115. {
  116. typedef BOOST_DEDUCED_TYPENAME detail::drop_front<N>::BOOST_NESTED_TEMPLATE
  117. apply<T>::type::head_type type;
  118. };
  119. template<int N, class T>
  120. struct element_impl<N, T, true /* IsConst */>
  121. {
  122. typedef BOOST_DEDUCED_TYPENAME detail::drop_front<N>::BOOST_NESTED_TEMPLATE
  123. apply<T>::type::head_type unqualified_type;
  124. typedef const unqualified_type type;
  125. };
  126. } // end of namespace detail
  127. template<int N, class T>
  128. struct element:
  129. public detail::element_impl<N, T, ::boost::is_const<T>::value>
  130. {
  131. };
  132. #endif
  133. // -get function templates -----------------------------------------------
  134. // Usage: get<N>(aTuple)
  135. // -- some traits classes for get functions
  136. // access traits lifted from detail namespace to be part of the interface,
  137. // (Joel de Guzman's suggestion). Rationale: get functions are part of the
  138. // interface, so should the way to express their return types be.
  139. template <class T> struct access_traits {
  140. typedef const T& const_type;
  141. typedef T& non_const_type;
  142. typedef const typename boost::remove_cv<T>::type& parameter_type;
  143. // used as the tuple constructors parameter types
  144. // Rationale: non-reference tuple element types can be cv-qualified.
  145. // It should be possible to initialize such types with temporaries,
  146. // and when binding temporaries to references, the reference must
  147. // be non-volatile and const. 8.5.3. (5)
  148. };
  149. template <class T> struct access_traits<T&> {
  150. typedef T& const_type;
  151. typedef T& non_const_type;
  152. typedef T& parameter_type;
  153. };
  154. // get function for non-const cons-lists, returns a reference to the element
  155. template<int N, class HT, class TT>
  156. inline typename access_traits<
  157. typename element<N, cons<HT, TT> >::type
  158. >::non_const_type
  159. get(cons<HT, TT>& c BOOST_APPEND_EXPLICIT_TEMPLATE_NON_TYPE(int, N)) {
  160. typedef BOOST_DEDUCED_TYPENAME detail::drop_front<N>::BOOST_NESTED_TEMPLATE
  161. apply<cons<HT, TT> > impl;
  162. typedef BOOST_DEDUCED_TYPENAME impl::type cons_element;
  163. return const_cast<cons_element&>(impl::call(c)).head;
  164. }
  165. // get function for const cons-lists, returns a const reference to
  166. // the element. If the element is a reference, returns the reference
  167. // as such (that is, can return a non-const reference)
  168. template<int N, class HT, class TT>
  169. inline typename access_traits<
  170. typename element<N, cons<HT, TT> >::type
  171. >::const_type
  172. get(const cons<HT, TT>& c BOOST_APPEND_EXPLICIT_TEMPLATE_NON_TYPE(int, N)) {
  173. typedef BOOST_DEDUCED_TYPENAME detail::drop_front<N>::BOOST_NESTED_TEMPLATE
  174. apply<cons<HT, TT> > impl;
  175. typedef BOOST_DEDUCED_TYPENAME impl::type cons_element;
  176. return impl::call(c).head;
  177. }
  178. // -- the cons template --------------------------------------------------
  179. namespace detail {
  180. // These helper templates wrap void types and plain function types.
  181. // The reationale is to allow one to write tuple types with those types
  182. // as elements, even though it is not possible to instantiate such object.
  183. // E.g: typedef tuple<void> some_type; // ok
  184. // but: some_type x; // fails
  185. template <class T> class non_storeable_type {
  186. non_storeable_type();
  187. };
  188. template <class T> struct wrap_non_storeable_type {
  189. typedef typename IF<
  190. ::boost::is_function<T>::value, non_storeable_type<T>, T
  191. >::RET type;
  192. };
  193. template <> struct wrap_non_storeable_type<void> {
  194. typedef non_storeable_type<void> type;
  195. };
  196. } // detail
  197. template <class HT, class TT>
  198. struct cons {
  199. typedef HT head_type;
  200. typedef TT tail_type;
  201. typedef typename
  202. detail::wrap_non_storeable_type<head_type>::type stored_head_type;
  203. stored_head_type head;
  204. tail_type tail;
  205. typename access_traits<stored_head_type>::non_const_type
  206. get_head() { return head; }
  207. typename access_traits<tail_type>::non_const_type
  208. get_tail() { return tail; }
  209. typename access_traits<stored_head_type>::const_type
  210. get_head() const { return head; }
  211. typename access_traits<tail_type>::const_type
  212. get_tail() const { return tail; }
  213. cons() : head(), tail() {}
  214. // cons() : head(detail::default_arg<HT>::f()), tail() {}
  215. // the argument for head is not strictly needed, but it prevents
  216. // array type elements. This is good, since array type elements
  217. // cannot be supported properly in any case (no assignment,
  218. // copy works only if the tails are exactly the same type, ...)
  219. cons(typename access_traits<stored_head_type>::parameter_type h,
  220. const tail_type& t)
  221. : head (h), tail(t) {}
  222. template <class T1, class T2, class T3, class T4, class T5,
  223. class T6, class T7, class T8, class T9, class T10>
  224. cons( T1& t1, T2& t2, T3& t3, T4& t4, T5& t5,
  225. T6& t6, T7& t7, T8& t8, T9& t9, T10& t10 )
  226. : head (t1),
  227. tail (t2, t3, t4, t5, t6, t7, t8, t9, t10, detail::cnull())
  228. {}
  229. template <class T2, class T3, class T4, class T5,
  230. class T6, class T7, class T8, class T9, class T10>
  231. cons( const null_type& /*t1*/, T2& t2, T3& t3, T4& t4, T5& t5,
  232. T6& t6, T7& t7, T8& t8, T9& t9, T10& t10 )
  233. : head (),
  234. tail (t2, t3, t4, t5, t6, t7, t8, t9, t10, detail::cnull())
  235. {}
  236. template <class HT2, class TT2>
  237. cons( const cons<HT2, TT2>& u ) : head(u.head), tail(u.tail) {}
  238. template <class HT2, class TT2>
  239. cons& operator=( const cons<HT2, TT2>& u ) {
  240. head=u.head; tail=u.tail; return *this;
  241. }
  242. // must define assignment operator explicitly, implicit version is
  243. // illformed if HT is a reference (12.8. (12))
  244. cons& operator=(const cons& u) {
  245. head = u.head; tail = u.tail; return *this;
  246. }
  247. template <class T1, class T2>
  248. cons& operator=( const std::pair<T1, T2>& u ) {
  249. BOOST_STATIC_ASSERT(length<cons>::value == 2); // check length = 2
  250. head = u.first; tail.head = u.second; return *this;
  251. }
  252. // get member functions (non-const and const)
  253. template <int N>
  254. typename access_traits<
  255. typename element<N, cons<HT, TT> >::type
  256. >::non_const_type
  257. get() {
  258. return boost::tuples::get<N>(*this); // delegate to non-member get
  259. }
  260. template <int N>
  261. typename access_traits<
  262. typename element<N, cons<HT, TT> >::type
  263. >::const_type
  264. get() const {
  265. return boost::tuples::get<N>(*this); // delegate to non-member get
  266. }
  267. };
  268. template <class HT>
  269. struct cons<HT, null_type> {
  270. typedef HT head_type;
  271. typedef null_type tail_type;
  272. typedef cons<HT, null_type> self_type;
  273. typedef typename
  274. detail::wrap_non_storeable_type<head_type>::type stored_head_type;
  275. stored_head_type head;
  276. typename access_traits<stored_head_type>::non_const_type
  277. get_head() { return head; }
  278. null_type get_tail() { return null_type(); }
  279. typename access_traits<stored_head_type>::const_type
  280. get_head() const { return head; }
  281. const null_type get_tail() const { return null_type(); }
  282. // cons() : head(detail::default_arg<HT>::f()) {}
  283. cons() : head() {}
  284. cons(typename access_traits<stored_head_type>::parameter_type h,
  285. const null_type& = null_type())
  286. : head (h) {}
  287. template<class T1>
  288. cons(T1& t1, const null_type&, const null_type&, const null_type&,
  289. const null_type&, const null_type&, const null_type&,
  290. const null_type&, const null_type&, const null_type&)
  291. : head (t1) {}
  292. cons(const null_type&,
  293. const null_type&, const null_type&, const null_type&,
  294. const null_type&, const null_type&, const null_type&,
  295. const null_type&, const null_type&, const null_type&)
  296. : head () {}
  297. template <class HT2>
  298. cons( const cons<HT2, null_type>& u ) : head(u.head) {}
  299. template <class HT2>
  300. cons& operator=(const cons<HT2, null_type>& u )
  301. { head = u.head; return *this; }
  302. // must define assignment operator explicitely, implicit version
  303. // is illformed if HT is a reference
  304. cons& operator=(const cons& u) { head = u.head; return *this; }
  305. template <int N>
  306. typename access_traits<
  307. typename element<N, self_type>::type
  308. >::non_const_type
  309. get(BOOST_EXPLICIT_TEMPLATE_NON_TYPE(int, N)) {
  310. return boost::tuples::get<N>(*this);
  311. }
  312. template <int N>
  313. typename access_traits<
  314. typename element<N, self_type>::type
  315. >::const_type
  316. get(BOOST_EXPLICIT_TEMPLATE_NON_TYPE(int, N)) const {
  317. return boost::tuples::get<N>(*this);
  318. }
  319. };
  320. // templates for finding out the length of the tuple -------------------
  321. template<class T>
  322. struct length {
  323. BOOST_STATIC_CONSTANT(int, value = 1 + length<typename T::tail_type>::value);
  324. };
  325. template<>
  326. struct length<tuple<> > {
  327. BOOST_STATIC_CONSTANT(int, value = 0);
  328. };
  329. template<>
  330. struct length<tuple<> const> {
  331. BOOST_STATIC_CONSTANT(int, value = 0);
  332. };
  333. template<>
  334. struct length<null_type> {
  335. BOOST_STATIC_CONSTANT(int, value = 0);
  336. };
  337. template<>
  338. struct length<null_type const> {
  339. BOOST_STATIC_CONSTANT(int, value = 0);
  340. };
  341. namespace detail {
  342. // Tuple to cons mapper --------------------------------------------------
  343. template <class T0, class T1, class T2, class T3, class T4,
  344. class T5, class T6, class T7, class T8, class T9>
  345. struct map_tuple_to_cons
  346. {
  347. typedef cons<T0,
  348. typename map_tuple_to_cons<T1, T2, T3, T4, T5,
  349. T6, T7, T8, T9, null_type>::type
  350. > type;
  351. };
  352. // The empty tuple is a null_type
  353. template <>
  354. 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>
  355. {
  356. typedef null_type type;
  357. };
  358. } // end detail
  359. // -------------------------------------------------------------------
  360. // -- tuple ------------------------------------------------------
  361. template <class T0, class T1, class T2, class T3, class T4,
  362. class T5, class T6, class T7, class T8, class T9>
  363. class tuple :
  364. public detail::map_tuple_to_cons<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>::type
  365. {
  366. public:
  367. typedef typename
  368. detail::map_tuple_to_cons<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>::type inherited;
  369. typedef typename inherited::head_type head_type;
  370. typedef typename inherited::tail_type tail_type;
  371. // access_traits<T>::parameter_type takes non-reference types as const T&
  372. tuple() {}
  373. tuple(typename access_traits<T0>::parameter_type t0)
  374. : inherited(t0, detail::cnull(), detail::cnull(), detail::cnull(),
  375. detail::cnull(), detail::cnull(), detail::cnull(),
  376. detail::cnull(), detail::cnull(), detail::cnull()) {}
  377. tuple(typename access_traits<T0>::parameter_type t0,
  378. typename access_traits<T1>::parameter_type t1)
  379. : inherited(t0, t1, detail::cnull(), detail::cnull(),
  380. detail::cnull(), detail::cnull(), detail::cnull(),
  381. detail::cnull(), detail::cnull(), detail::cnull()) {}
  382. tuple(typename access_traits<T0>::parameter_type t0,
  383. typename access_traits<T1>::parameter_type t1,
  384. typename access_traits<T2>::parameter_type t2)
  385. : inherited(t0, t1, t2, detail::cnull(), detail::cnull(),
  386. detail::cnull(), detail::cnull(), detail::cnull(),
  387. detail::cnull(), detail::cnull()) {}
  388. tuple(typename access_traits<T0>::parameter_type t0,
  389. typename access_traits<T1>::parameter_type t1,
  390. typename access_traits<T2>::parameter_type t2,
  391. typename access_traits<T3>::parameter_type t3)
  392. : inherited(t0, t1, t2, t3, detail::cnull(), detail::cnull(),
  393. detail::cnull(), detail::cnull(), detail::cnull(),
  394. detail::cnull()) {}
  395. tuple(typename access_traits<T0>::parameter_type t0,
  396. typename access_traits<T1>::parameter_type t1,
  397. typename access_traits<T2>::parameter_type t2,
  398. typename access_traits<T3>::parameter_type t3,
  399. typename access_traits<T4>::parameter_type t4)
  400. : inherited(t0, t1, t2, t3, t4, detail::cnull(), detail::cnull(),
  401. detail::cnull(), detail::cnull(), detail::cnull()) {}
  402. tuple(typename access_traits<T0>::parameter_type t0,
  403. typename access_traits<T1>::parameter_type t1,
  404. typename access_traits<T2>::parameter_type t2,
  405. typename access_traits<T3>::parameter_type t3,
  406. typename access_traits<T4>::parameter_type t4,
  407. typename access_traits<T5>::parameter_type t5)
  408. : inherited(t0, t1, t2, t3, t4, t5, detail::cnull(), detail::cnull(),
  409. detail::cnull(), detail::cnull()) {}
  410. tuple(typename access_traits<T0>::parameter_type t0,
  411. typename access_traits<T1>::parameter_type t1,
  412. typename access_traits<T2>::parameter_type t2,
  413. typename access_traits<T3>::parameter_type t3,
  414. typename access_traits<T4>::parameter_type t4,
  415. typename access_traits<T5>::parameter_type t5,
  416. typename access_traits<T6>::parameter_type t6)
  417. : inherited(t0, t1, t2, t3, t4, t5, t6, detail::cnull(),
  418. detail::cnull(), detail::cnull()) {}
  419. tuple(typename access_traits<T0>::parameter_type t0,
  420. typename access_traits<T1>::parameter_type t1,
  421. typename access_traits<T2>::parameter_type t2,
  422. typename access_traits<T3>::parameter_type t3,
  423. typename access_traits<T4>::parameter_type t4,
  424. typename access_traits<T5>::parameter_type t5,
  425. typename access_traits<T6>::parameter_type t6,
  426. typename access_traits<T7>::parameter_type t7)
  427. : inherited(t0, t1, t2, t3, t4, t5, t6, t7, detail::cnull(),
  428. detail::cnull()) {}
  429. tuple(typename access_traits<T0>::parameter_type t0,
  430. typename access_traits<T1>::parameter_type t1,
  431. typename access_traits<T2>::parameter_type t2,
  432. typename access_traits<T3>::parameter_type t3,
  433. typename access_traits<T4>::parameter_type t4,
  434. typename access_traits<T5>::parameter_type t5,
  435. typename access_traits<T6>::parameter_type t6,
  436. typename access_traits<T7>::parameter_type t7,
  437. typename access_traits<T8>::parameter_type t8)
  438. : inherited(t0, t1, t2, t3, t4, t5, t6, t7, t8, detail::cnull()) {}
  439. tuple(typename access_traits<T0>::parameter_type t0,
  440. typename access_traits<T1>::parameter_type t1,
  441. typename access_traits<T2>::parameter_type t2,
  442. typename access_traits<T3>::parameter_type t3,
  443. typename access_traits<T4>::parameter_type t4,
  444. typename access_traits<T5>::parameter_type t5,
  445. typename access_traits<T6>::parameter_type t6,
  446. typename access_traits<T7>::parameter_type t7,
  447. typename access_traits<T8>::parameter_type t8,
  448. typename access_traits<T9>::parameter_type t9)
  449. : inherited(t0, t1, t2, t3, t4, t5, t6, t7, t8, t9) {}
  450. template<class U1, class U2>
  451. tuple(const cons<U1, U2>& p) : inherited(p) {}
  452. template <class U1, class U2>
  453. tuple& operator=(const cons<U1, U2>& k) {
  454. inherited::operator=(k);
  455. return *this;
  456. }
  457. template <class U1, class U2>
  458. tuple& operator=(const std::pair<U1, U2>& k) {
  459. BOOST_STATIC_ASSERT(length<tuple>::value == 2);// check_length = 2
  460. this->head = k.first;
  461. this->tail.head = k.second;
  462. return *this;
  463. }
  464. };
  465. // The empty tuple
  466. template <>
  467. class tuple<null_type, null_type, null_type, null_type, null_type, null_type, null_type, null_type, null_type, null_type> :
  468. public null_type
  469. {
  470. public:
  471. typedef null_type inherited;
  472. };
  473. // Swallows any assignment (by Doug Gregor)
  474. namespace detail {
  475. struct swallow_assign;
  476. typedef void (detail::swallow_assign::*ignore_t)();
  477. struct swallow_assign {
  478. swallow_assign(ignore_t(*)(ignore_t)) {}
  479. template<typename T>
  480. swallow_assign const& operator=(const T&) const {
  481. return *this;
  482. }
  483. };
  484. } // namespace detail
  485. // "ignore" allows tuple positions to be ignored when using "tie".
  486. inline detail::ignore_t ignore(detail::ignore_t) { return 0; }
  487. // ---------------------------------------------------------------------------
  488. // The call_traits for make_tuple
  489. // Honours the reference_wrapper class.
  490. // Must be instantiated with plain or const plain types (not with references)
  491. // from template<class T> foo(const T& t) : make_tuple_traits<const T>::type
  492. // from template<class T> foo(T& t) : make_tuple_traits<T>::type
  493. // Conversions:
  494. // T -> T,
  495. // references -> compile_time_error
  496. // reference_wrapper<T> -> T&
  497. // const reference_wrapper<T> -> T&
  498. // array -> const ref array
  499. template<class T>
  500. struct make_tuple_traits {
  501. typedef T type;
  502. // commented away, see below (JJ)
  503. // typedef typename IF<
  504. // boost::is_function<T>::value,
  505. // T&,
  506. // T>::RET type;
  507. };
  508. // The is_function test was there originally for plain function types,
  509. // which can't be stored as such (we must either store them as references or
  510. // pointers). Such a type could be formed if make_tuple was called with a
  511. // reference to a function.
  512. // But this would mean that a const qualified function type was formed in
  513. // the make_tuple function and hence make_tuple can't take a function
  514. // reference as a parameter, and thus T can't be a function type.
  515. // So is_function test was removed.
  516. // (14.8.3. says that type deduction fails if a cv-qualified function type
  517. // is created. (It only applies for the case of explicitly specifying template
  518. // args, though?)) (JJ)
  519. template<class T>
  520. struct make_tuple_traits<T&> {
  521. typedef typename
  522. detail::generate_error<T&>::
  523. do_not_use_with_reference_type error;
  524. };
  525. // Arrays can't be stored as plain types; convert them to references.
  526. // All arrays are converted to const. This is because make_tuple takes its
  527. // parameters as const T& and thus the knowledge of the potential
  528. // non-constness of actual argument is lost.
  529. template<class T, int n> struct make_tuple_traits <T[n]> {
  530. typedef const T (&type)[n];
  531. };
  532. template<class T, int n>
  533. struct make_tuple_traits<const T[n]> {
  534. typedef const T (&type)[n];
  535. };
  536. template<class T, int n> struct make_tuple_traits<volatile T[n]> {
  537. typedef const volatile T (&type)[n];
  538. };
  539. template<class T, int n>
  540. struct make_tuple_traits<const volatile T[n]> {
  541. typedef const volatile T (&type)[n];
  542. };
  543. template<class T>
  544. struct make_tuple_traits<reference_wrapper<T> >{
  545. typedef T& type;
  546. };
  547. template<class T>
  548. struct make_tuple_traits<const reference_wrapper<T> >{
  549. typedef T& type;
  550. };
  551. template<>
  552. struct make_tuple_traits<detail::ignore_t(detail::ignore_t)> {
  553. typedef detail::swallow_assign type;
  554. };
  555. namespace detail {
  556. // a helper traits to make the make_tuple functions shorter (Vesa Karvonen's
  557. // suggestion)
  558. template <
  559. class T0 = null_type, class T1 = null_type, class T2 = null_type,
  560. class T3 = null_type, class T4 = null_type, class T5 = null_type,
  561. class T6 = null_type, class T7 = null_type, class T8 = null_type,
  562. class T9 = null_type
  563. >
  564. struct make_tuple_mapper {
  565. typedef
  566. tuple<typename make_tuple_traits<T0>::type,
  567. typename make_tuple_traits<T1>::type,
  568. typename make_tuple_traits<T2>::type,
  569. typename make_tuple_traits<T3>::type,
  570. typename make_tuple_traits<T4>::type,
  571. typename make_tuple_traits<T5>::type,
  572. typename make_tuple_traits<T6>::type,
  573. typename make_tuple_traits<T7>::type,
  574. typename make_tuple_traits<T8>::type,
  575. typename make_tuple_traits<T9>::type> type;
  576. };
  577. } // end detail
  578. // -make_tuple function templates -----------------------------------
  579. inline tuple<> make_tuple() {
  580. return tuple<>();
  581. }
  582. template<class T0>
  583. inline typename detail::make_tuple_mapper<T0>::type
  584. make_tuple(const T0& t0) {
  585. typedef typename detail::make_tuple_mapper<T0>::type t;
  586. return t(t0);
  587. }
  588. template<class T0, class T1>
  589. inline typename detail::make_tuple_mapper<T0, T1>::type
  590. make_tuple(const T0& t0, const T1& t1) {
  591. typedef typename detail::make_tuple_mapper<T0, T1>::type t;
  592. return t(t0, t1);
  593. }
  594. template<class T0, class T1, class T2>
  595. inline typename detail::make_tuple_mapper<T0, T1, T2>::type
  596. make_tuple(const T0& t0, const T1& t1, const T2& t2) {
  597. typedef typename detail::make_tuple_mapper<T0, T1, T2>::type t;
  598. return t(t0, t1, t2);
  599. }
  600. template<class T0, class T1, class T2, class T3>
  601. inline typename detail::make_tuple_mapper<T0, T1, T2, T3>::type
  602. make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3) {
  603. typedef typename detail::make_tuple_mapper<T0, T1, T2, T3>::type t;
  604. return t(t0, t1, t2, t3);
  605. }
  606. template<class T0, class T1, class T2, class T3, class T4>
  607. inline typename detail::make_tuple_mapper<T0, T1, T2, T3, T4>::type
  608. make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3,
  609. const T4& t4) {
  610. typedef typename detail::make_tuple_mapper<T0, T1, T2, T3, T4>::type t;
  611. return t(t0, t1, t2, t3, t4);
  612. }
  613. template<class T0, class T1, class T2, class T3, class T4, class T5>
  614. inline typename detail::make_tuple_mapper<T0, T1, T2, T3, T4, T5>::type
  615. make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3,
  616. const T4& t4, const T5& t5) {
  617. typedef typename detail::make_tuple_mapper<T0, T1, T2, T3, T4, T5>::type t;
  618. return t(t0, t1, t2, t3, t4, t5);
  619. }
  620. template<class T0, class T1, class T2, class T3, class T4, class T5, class T6>
  621. inline typename detail::make_tuple_mapper<T0, T1, T2, T3, T4, T5, T6>::type
  622. make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3,
  623. const T4& t4, const T5& t5, const T6& t6) {
  624. typedef typename detail::make_tuple_mapper
  625. <T0, T1, T2, T3, T4, T5, T6>::type t;
  626. return t(t0, t1, t2, t3, t4, t5, t6);
  627. }
  628. template<class T0, class T1, class T2, class T3, class T4, class T5, class T6,
  629. class T7>
  630. inline typename detail::make_tuple_mapper<T0, T1, T2, T3, T4, T5, T6, T7>::type
  631. make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3,
  632. const T4& t4, const T5& t5, const T6& t6, const T7& t7) {
  633. typedef typename detail::make_tuple_mapper
  634. <T0, T1, T2, T3, T4, T5, T6, T7>::type t;
  635. return t(t0, t1, t2, t3, t4, t5, t6, t7);
  636. }
  637. template<class T0, class T1, class T2, class T3, class T4, class T5, class T6,
  638. class T7, class T8>
  639. inline typename detail::make_tuple_mapper
  640. <T0, T1, T2, T3, T4, T5, T6, T7, T8>::type
  641. make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3,
  642. const T4& t4, const T5& t5, const T6& t6, const T7& t7,
  643. const T8& t8) {
  644. typedef typename detail::make_tuple_mapper
  645. <T0, T1, T2, T3, T4, T5, T6, T7, T8>::type t;
  646. return t(t0, t1, t2, t3, t4, t5, t6, t7, t8);
  647. }
  648. template<class T0, class T1, class T2, class T3, class T4, class T5, class T6,
  649. class T7, class T8, class T9>
  650. inline typename detail::make_tuple_mapper
  651. <T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>::type
  652. make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3,
  653. const T4& t4, const T5& t5, const T6& t6, const T7& t7,
  654. const T8& t8, const T9& t9) {
  655. typedef typename detail::make_tuple_mapper
  656. <T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>::type t;
  657. return t(t0, t1, t2, t3, t4, t5, t6, t7, t8, t9);
  658. }
  659. namespace detail {
  660. template<class T>
  661. struct tie_traits {
  662. typedef T& type;
  663. };
  664. template<>
  665. struct tie_traits<ignore_t(ignore_t)> {
  666. typedef swallow_assign type;
  667. };
  668. template<>
  669. struct tie_traits<void> {
  670. typedef null_type type;
  671. };
  672. template <
  673. class T0 = void, class T1 = void, class T2 = void,
  674. class T3 = void, class T4 = void, class T5 = void,
  675. class T6 = void, class T7 = void, class T8 = void,
  676. class T9 = void
  677. >
  678. struct tie_mapper {
  679. typedef
  680. tuple<typename tie_traits<T0>::type,
  681. typename tie_traits<T1>::type,
  682. typename tie_traits<T2>::type,
  683. typename tie_traits<T3>::type,
  684. typename tie_traits<T4>::type,
  685. typename tie_traits<T5>::type,
  686. typename tie_traits<T6>::type,
  687. typename tie_traits<T7>::type,
  688. typename tie_traits<T8>::type,
  689. typename tie_traits<T9>::type> type;
  690. };
  691. }
  692. // Tie function templates -------------------------------------------------
  693. template<class T0>
  694. inline typename detail::tie_mapper<T0>::type
  695. tie(T0& t0) {
  696. typedef typename detail::tie_mapper<T0>::type t;
  697. return t(t0);
  698. }
  699. template<class T0, class T1>
  700. inline typename detail::tie_mapper<T0, T1>::type
  701. tie(T0& t0, T1& t1) {
  702. typedef typename detail::tie_mapper<T0, T1>::type t;
  703. return t(t0, t1);
  704. }
  705. template<class T0, class T1, class T2>
  706. inline typename detail::tie_mapper<T0, T1, T2>::type
  707. tie(T0& t0, T1& t1, T2& t2) {
  708. typedef typename detail::tie_mapper<T0, T1, T2>::type t;
  709. return t(t0, t1, t2);
  710. }
  711. template<class T0, class T1, class T2, class T3>
  712. inline typename detail::tie_mapper<T0, T1, T2, T3>::type
  713. tie(T0& t0, T1& t1, T2& t2, T3& t3) {
  714. typedef typename detail::tie_mapper<T0, T1, T2, T3>::type t;
  715. return t(t0, t1, t2, t3);
  716. }
  717. template<class T0, class T1, class T2, class T3, class T4>
  718. inline typename detail::tie_mapper<T0, T1, T2, T3, T4>::type
  719. tie(T0& t0, T1& t1, T2& t2, T3& t3,
  720. T4& t4) {
  721. typedef typename detail::tie_mapper<T0, T1, T2, T3, T4>::type t;
  722. return t(t0, t1, t2, t3, t4);
  723. }
  724. template<class T0, class T1, class T2, class T3, class T4, class T5>
  725. inline typename detail::tie_mapper<T0, T1, T2, T3, T4, T5>::type
  726. tie(T0& t0, T1& t1, T2& t2, T3& t3,
  727. T4& t4, T5& t5) {
  728. typedef typename detail::tie_mapper<T0, T1, T2, T3, T4, T5>::type t;
  729. return t(t0, t1, t2, t3, t4, t5);
  730. }
  731. template<class T0, class T1, class T2, class T3, class T4, class T5, class T6>
  732. inline typename detail::tie_mapper<T0, T1, T2, T3, T4, T5, T6>::type
  733. tie(T0& t0, T1& t1, T2& t2, T3& t3,
  734. T4& t4, T5& t5, T6& t6) {
  735. typedef typename detail::tie_mapper
  736. <T0, T1, T2, T3, T4, T5, T6>::type t;
  737. return t(t0, t1, t2, t3, t4, t5, t6);
  738. }
  739. template<class T0, class T1, class T2, class T3, class T4, class T5, class T6,
  740. class T7>
  741. inline typename detail::tie_mapper<T0, T1, T2, T3, T4, T5, T6, T7>::type
  742. tie(T0& t0, T1& t1, T2& t2, T3& t3,
  743. T4& t4, T5& t5, T6& t6, T7& t7) {
  744. typedef typename detail::tie_mapper
  745. <T0, T1, T2, T3, T4, T5, T6, T7>::type t;
  746. return t(t0, t1, t2, t3, t4, t5, t6, t7);
  747. }
  748. template<class T0, class T1, class T2, class T3, class T4, class T5, class T6,
  749. class T7, class T8>
  750. inline typename detail::tie_mapper
  751. <T0, T1, T2, T3, T4, T5, T6, T7, T8>::type
  752. tie(T0& t0, T1& t1, T2& t2, T3& t3,
  753. T4& t4, T5& t5, T6& t6, T7& t7,
  754. T8& t8) {
  755. typedef typename detail::tie_mapper
  756. <T0, T1, T2, T3, T4, T5, T6, T7, T8>::type t;
  757. return t(t0, t1, t2, t3, t4, t5, t6, t7, t8);
  758. }
  759. template<class T0, class T1, class T2, class T3, class T4, class T5, class T6,
  760. class T7, class T8, class T9>
  761. inline typename detail::tie_mapper
  762. <T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>::type
  763. tie(T0& t0, T1& t1, T2& t2, T3& t3,
  764. T4& t4, T5& t5, T6& t6, T7& t7,
  765. T8& t8, T9& t9) {
  766. typedef typename detail::tie_mapper
  767. <T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>::type t;
  768. return t(t0, t1, t2, t3, t4, t5, t6, t7, t8, t9);
  769. }
  770. template <class T0, class T1, class T2, class T3, class T4,
  771. class T5, class T6, class T7, class T8, class T9>
  772. void swap(tuple<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>& lhs,
  773. tuple<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>& rhs);
  774. inline void swap(null_type&, null_type&) {}
  775. template<class HH>
  776. inline void swap(cons<HH, null_type>& lhs, cons<HH, null_type>& rhs) {
  777. ::boost::swap(lhs.head, rhs.head);
  778. }
  779. template<class HH, class TT>
  780. inline void swap(cons<HH, TT>& lhs, cons<HH, TT>& rhs) {
  781. ::boost::swap(lhs.head, rhs.head);
  782. ::boost::tuples::swap(lhs.tail, rhs.tail);
  783. }
  784. template <class T0, class T1, class T2, class T3, class T4,
  785. class T5, class T6, class T7, class T8, class T9>
  786. inline void swap(tuple<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>& lhs,
  787. tuple<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>& rhs) {
  788. typedef tuple<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9> tuple_type;
  789. typedef typename tuple_type::inherited base;
  790. ::boost::tuples::swap(static_cast<base&>(lhs), static_cast<base&>(rhs));
  791. }
  792. } // end of namespace tuples
  793. } // end of namespace boost
  794. #endif // BOOST_TUPLE_BASIC_HPP