williamr@2: //  tuple_basic.hpp -----------------------------------------------------
williamr@2: 
williamr@2: // Copyright (C) 1999, 2000 Jaakko Järvi (jaakko.jarvi@cs.utu.fi)
williamr@2: //
williamr@2: // Distributed under the Boost Software License, Version 1.0. (See
williamr@2: // accompanying file LICENSE_1_0.txt or copy at
williamr@2: // http://www.boost.org/LICENSE_1_0.txt)
williamr@2: 
williamr@2: // For more information, see http://www.boost.org
williamr@2: 
williamr@2: // Outside help:
williamr@2: // This and that, Gary Powell.
williamr@2: // Fixed return types for get_head/get_tail
williamr@2: // ( and other bugs ) per suggestion of Jens Maurer
williamr@2: // simplified element type accessors + bug fix  (Jeremy Siek)
williamr@2: // Several changes/additions according to suggestions by Douglas Gregor,
williamr@2: // William Kempf, Vesa Karvonen, John Max Skaller, Ed Brey, Beman Dawes,
williamr@2: // David Abrahams.
williamr@2: 
williamr@2: // Revision history:
williamr@2: // 2002 05 01 Hugo Duncan: Fix for Borland after Jaakko's previous changes
williamr@2: // 2002 04 18 Jaakko: tuple element types can be void or plain function
williamr@2: //                    types, as long as no object is created.
williamr@2: //                    Tuple objects can no hold even noncopyable types
williamr@2: //                    such as arrays.
williamr@2: // 2001 10 22 John Maddock
williamr@2: //      Fixes for Borland C++
williamr@2: // 2001 08 30 David Abrahams
williamr@2: //      Added default constructor for cons<>.
williamr@2: // -----------------------------------------------------------------
williamr@2: 
williamr@2: #ifndef BOOST_TUPLE_BASIC_HPP
williamr@2: #define BOOST_TUPLE_BASIC_HPP
williamr@2: 
williamr@2: 
williamr@2: #include <utility> // needed for the assignment from pair to tuple
williamr@2: 
williamr@2: #include "boost/type_traits/cv_traits.hpp"
williamr@2: #include "boost/type_traits/function_traits.hpp"
williamr@2: 
williamr@2: #include "boost/detail/workaround.hpp" // needed for BOOST_WORKAROUND
williamr@2: 
williamr@2: namespace boost {
williamr@2: namespace tuples {
williamr@2: 
williamr@2: // -- null_type --------------------------------------------------------
williamr@2: struct null_type {};
williamr@2: 
williamr@2: // a helper function to provide a const null_type type temporary
williamr@2: namespace detail {
williamr@2:   inline const null_type cnull() { return null_type(); }
williamr@2: 
williamr@2: 
williamr@2: // -- if construct ------------------------------------------------
williamr@2: // Proposed by Krzysztof Czarnecki and Ulrich Eisenecker
williamr@2: 
williamr@2: template <bool If, class Then, class Else> struct IF { typedef Then RET; };
williamr@2: 
williamr@2: template <class Then, class Else> struct IF<false, Then, Else> {
williamr@2:   typedef Else RET;
williamr@2: };
williamr@2: 
williamr@2: } // end detail
williamr@2: 
williamr@2: // - cons forward declaration -----------------------------------------------
williamr@2: template <class HT, class TT> struct cons;
williamr@2: 
williamr@2: 
williamr@2: // - tuple forward declaration -----------------------------------------------
williamr@2: template <
williamr@2:   class T0 = null_type, class T1 = null_type, class T2 = null_type,
williamr@2:   class T3 = null_type, class T4 = null_type, class T5 = null_type,
williamr@2:   class T6 = null_type, class T7 = null_type, class T8 = null_type,
williamr@2:   class T9 = null_type>
williamr@2: class tuple;
williamr@2: 
williamr@2: // tuple_length forward declaration
williamr@2: template<class T> struct length;
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: namespace detail {
williamr@2: 
williamr@2: // -- generate error template, referencing to non-existing members of this
williamr@2: // template is used to produce compilation errors intentionally
williamr@2: template<class T>
williamr@2: class generate_error;
williamr@2: 
williamr@2: // - cons getters --------------------------------------------------------
williamr@2: // called: get_class<N>::get<RETURN_TYPE>(aTuple)
williamr@2: 
williamr@2: template< int N >
williamr@2: struct get_class {
williamr@2:   template<class RET, class HT, class TT >
williamr@2:   inline static RET get(const cons<HT, TT>& t)
williamr@2:   {
williamr@2: #if BOOST_WORKAROUND(__IBMCPP__,==600)
williamr@2:     // vacpp 6.0 is not very consistent regarding the member template keyword
williamr@2:     // Here it generates an error when the template keyword is used.
williamr@2:     return get_class<N-1>::get<RET>(t.tail);
williamr@2: #else
williamr@2:     return get_class<N-1>::BOOST_NESTED_TEMPLATE get<RET>(t.tail);
williamr@2: #endif
williamr@2:   }
williamr@2:   template<class RET, class HT, class TT >
williamr@2:   inline static RET get(cons<HT, TT>& t)
williamr@2:   {
williamr@2: #if BOOST_WORKAROUND(__IBMCPP__,==600)
williamr@2:     return get_class<N-1>::get<RET>(t.tail);
williamr@2: #else
williamr@2:     return get_class<N-1>::BOOST_NESTED_TEMPLATE get<RET>(t.tail);
williamr@2: #endif
williamr@2:   }
williamr@2: };
williamr@2: 
williamr@2: template<>
williamr@2: struct get_class<0> {
williamr@2:   template<class RET, class HT, class TT>
williamr@2:   inline static RET get(const cons<HT, TT>& t)
williamr@2:   {
williamr@2:     return t.head;
williamr@2:   }
williamr@2:   template<class RET, class HT, class TT>
williamr@2:   inline static RET get(cons<HT, TT>& t)
williamr@2:   {
williamr@2:     return t.head;
williamr@2:   }
williamr@2: };
williamr@2: 
williamr@2: } // end of namespace detail
williamr@2: 
williamr@2: 
williamr@2: // -cons type accessors ----------------------------------------
williamr@2: // typename tuples::element<N,T>::type gets the type of the
williamr@2: // Nth element ot T, first element is at index 0
williamr@2: // -------------------------------------------------------
williamr@2: 
williamr@2: #ifndef BOOST_NO_CV_SPECIALIZATIONS
williamr@2: 
williamr@2: template<int N, class T>
williamr@2: struct element
williamr@2: {
williamr@2: private:
williamr@2:   typedef typename T::tail_type Next;
williamr@2: public:
williamr@2:   typedef typename element<N-1, Next>::type type;
williamr@2: };
williamr@2: template<class T>
williamr@2: struct element<0,T>
williamr@2: {
williamr@2:   typedef typename T::head_type type;
williamr@2: };
williamr@2: 
williamr@2: template<int N, class T>
williamr@2: struct element<N, const T>
williamr@2: {
williamr@2: private:
williamr@2:   typedef typename T::tail_type Next;
williamr@2:   typedef typename element<N-1, Next>::type unqualified_type;
williamr@2: public:
williamr@2: #if BOOST_WORKAROUND(__BORLANDC__,<0x600)
williamr@2:   typedef const unqualified_type type;
williamr@2: #else
williamr@2:   typedef typename boost::add_const<unqualified_type>::type type;
williamr@2: #endif
williamr@2: 
williamr@2: };
williamr@2: template<class T>
williamr@2: struct element<0,const T>
williamr@2: {
williamr@2: #if BOOST_WORKAROUND(__BORLANDC__,<0x600)
williamr@2:   typedef const typename T::head_type type;
williamr@2: #else
williamr@2:   typedef typename boost::add_const<typename T::head_type>::type type;
williamr@2: #endif
williamr@2: };
williamr@2: 
williamr@2: #else // def BOOST_NO_CV_SPECIALIZATIONS
williamr@2: 
williamr@2: namespace detail {
williamr@2: 
williamr@2: template<int N, class T, bool IsConst>
williamr@2: struct element_impl
williamr@2: {
williamr@2: private:
williamr@2:   typedef typename T::tail_type Next;
williamr@2: public:
williamr@2:   typedef typename element_impl<N-1, Next, IsConst>::type type;
williamr@2: };
williamr@2: 
williamr@2: template<int N, class T>
williamr@2: struct element_impl<N, T, true /* IsConst */>
williamr@2: {
williamr@2: private:
williamr@2:   typedef typename T::tail_type Next;
williamr@2: public:
williamr@2:   typedef const typename element_impl<N-1, Next, true>::type type;
williamr@2: };
williamr@2: 
williamr@2: template<class T>
williamr@2: struct element_impl<0, T, false /* IsConst */>
williamr@2: {
williamr@2:   typedef typename T::head_type type;
williamr@2: };
williamr@2: 
williamr@2: template<class T>
williamr@2: struct element_impl<0, T, true /* IsConst */>
williamr@2: {
williamr@2:   typedef const typename T::head_type type;
williamr@2: };
williamr@2: 
williamr@2: } // end of namespace detail
williamr@2: 
williamr@2: 
williamr@2: template<int N, class T>
williamr@2: struct element: 
williamr@2:   public detail::element_impl<N, T, ::boost::is_const<T>::value>
williamr@2: {
williamr@2: };
williamr@2: 
williamr@2: #endif
williamr@2: 
williamr@2: 
williamr@2: // -get function templates -----------------------------------------------
williamr@2: // Usage: get<N>(aTuple)
williamr@2: 
williamr@2: // -- some traits classes for get functions
williamr@2: 
williamr@2: // access traits lifted from detail namespace to be part of the interface,
williamr@2: // (Joel de Guzman's suggestion). Rationale: get functions are part of the
williamr@2: // interface, so should the way to express their return types be.
williamr@2: 
williamr@2: template <class T> struct access_traits {
williamr@2:   typedef const T& const_type;
williamr@2:   typedef T& non_const_type;
williamr@2: 
williamr@2:   typedef const typename boost::remove_cv<T>::type& parameter_type;
williamr@2: 
williamr@2: // used as the tuple constructors parameter types
williamr@2: // Rationale: non-reference tuple element types can be cv-qualified.
williamr@2: // It should be possible to initialize such types with temporaries,
williamr@2: // and when binding temporaries to references, the reference must
williamr@2: // be non-volatile and const. 8.5.3. (5)
williamr@2: };
williamr@2: 
williamr@2: template <class T> struct access_traits<T&> {
williamr@2: 
williamr@2:   typedef T& const_type;
williamr@2:   typedef T& non_const_type;
williamr@2: 
williamr@2:   typedef T& parameter_type;
williamr@2: };
williamr@2: 
williamr@2: // get function for non-const cons-lists, returns a reference to the element
williamr@2: 
williamr@2: template<int N, class HT, class TT>
williamr@2: inline typename access_traits<
williamr@2:                   typename element<N, cons<HT, TT> >::type
williamr@2:                 >::non_const_type
williamr@2: get(cons<HT, TT>& c BOOST_APPEND_EXPLICIT_TEMPLATE_NON_TYPE(int, N)) {
williamr@2: #if BOOST_WORKAROUND(__IBMCPP__,==600 )
williamr@2:   return detail::get_class<N>::
williamr@2: #else
williamr@2:   return detail::get_class<N>::BOOST_NESTED_TEMPLATE
williamr@2: #endif
williamr@2:          get<
williamr@2:            typename access_traits<
williamr@2:              typename element<N, cons<HT, TT> >::type
williamr@2:            >::non_const_type,
williamr@2:            HT,TT
williamr@2:          >(c);
williamr@2: }
williamr@2: 
williamr@2: // get function for const cons-lists, returns a const reference to
williamr@2: // the element. If the element is a reference, returns the reference
williamr@2: // as such (that is, can return a non-const reference)
williamr@2: template<int N, class HT, class TT>
williamr@2: inline typename access_traits<
williamr@2:                   typename element<N, cons<HT, TT> >::type
williamr@2:                 >::const_type
williamr@2: get(const cons<HT, TT>& c BOOST_APPEND_EXPLICIT_TEMPLATE_NON_TYPE(int, N)) {
williamr@2: #if BOOST_WORKAROUND(__IBMCPP__,==600)
williamr@2:   return detail::get_class<N>::
williamr@2: #else
williamr@2:   return detail::get_class<N>::BOOST_NESTED_TEMPLATE
williamr@2: #endif
williamr@2:          get<
williamr@2:            typename access_traits<
williamr@2:              typename element<N, cons<HT, TT> >::type
williamr@2:            >::const_type,
williamr@2:            HT,TT
williamr@2:          >(c);
williamr@2: }
williamr@2: 
williamr@2: // -- the cons template  --------------------------------------------------
williamr@2: namespace detail {
williamr@2: 
williamr@2: //  These helper templates wrap void types and plain function types.
williamr@2: //  The reationale is to allow one to write tuple types with those types
williamr@2: //  as elements, even though it is not possible to instantiate such object.
williamr@2: //  E.g: typedef tuple<void> some_type; // ok
williamr@2: //  but: some_type x; // fails
williamr@2: 
williamr@2: template <class T> class non_storeable_type {
williamr@2:   non_storeable_type();
williamr@2: };
williamr@2: 
williamr@2: template <class T> struct wrap_non_storeable_type {
williamr@2:   typedef typename IF<
williamr@2:     ::boost::is_function<T>::value, non_storeable_type<T>, T
williamr@2:   >::RET type;
williamr@2: };
williamr@2: template <> struct wrap_non_storeable_type<void> {
williamr@2:   typedef non_storeable_type<void> type;
williamr@2: };
williamr@2: 
williamr@2: } // detail
williamr@2: 
williamr@2: template <class HT, class TT>
williamr@2: struct cons {
williamr@2: 
williamr@2:   typedef HT head_type;
williamr@2:   typedef TT tail_type;
williamr@2: 
williamr@2:   typedef typename
williamr@2:     detail::wrap_non_storeable_type<head_type>::type stored_head_type;
williamr@2: 
williamr@2:   stored_head_type head;
williamr@2:   tail_type tail;
williamr@2: 
williamr@2:   typename access_traits<stored_head_type>::non_const_type
williamr@2:   get_head() { return head; }
williamr@2: 
williamr@2:   typename access_traits<tail_type>::non_const_type
williamr@2:   get_tail() { return tail; }
williamr@2: 
williamr@2:   typename access_traits<stored_head_type>::const_type
williamr@2:   get_head() const { return head; }
williamr@2: 
williamr@2:   typename access_traits<tail_type>::const_type
williamr@2:   get_tail() const { return tail; }
williamr@2: 
williamr@2:   cons() : head(), tail() {}
williamr@2:   //  cons() : head(detail::default_arg<HT>::f()), tail() {}
williamr@2: 
williamr@2:   // the argument for head is not strictly needed, but it prevents
williamr@2:   // array type elements. This is good, since array type elements
williamr@2:   // cannot be supported properly in any case (no assignment,
williamr@2:   // copy works only if the tails are exactly the same type, ...)
williamr@2: 
williamr@2:   cons(typename access_traits<stored_head_type>::parameter_type h,
williamr@2:        const tail_type& t)
williamr@2:     : head (h), tail(t) {}
williamr@2: 
williamr@2:   template <class T1, class T2, class T3, class T4, class T5,
williamr@2:             class T6, class T7, class T8, class T9, class T10>
williamr@2:   cons( T1& t1, T2& t2, T3& t3, T4& t4, T5& t5,
williamr@2:         T6& t6, T7& t7, T8& t8, T9& t9, T10& t10 )
williamr@2:     : head (t1),
williamr@2:       tail (t2, t3, t4, t5, t6, t7, t8, t9, t10, detail::cnull())
williamr@2:       {}
williamr@2: 
williamr@2:   template <class T2, class T3, class T4, class T5,
williamr@2:             class T6, class T7, class T8, class T9, class T10>
williamr@2:   cons( const null_type& /*t1*/, T2& t2, T3& t3, T4& t4, T5& t5,
williamr@2:         T6& t6, T7& t7, T8& t8, T9& t9, T10& t10 )
williamr@2:     : head (),
williamr@2:       tail (t2, t3, t4, t5, t6, t7, t8, t9, t10, detail::cnull())
williamr@2:       {}
williamr@2: 
williamr@2: 
williamr@2:   template <class HT2, class TT2>
williamr@2:   cons( const cons<HT2, TT2>& u ) : head(u.head), tail(u.tail) {}
williamr@2: 
williamr@2:   template <class HT2, class TT2>
williamr@2:   cons& operator=( const cons<HT2, TT2>& u ) {
williamr@2:     head=u.head; tail=u.tail; return *this;
williamr@2:   }
williamr@2: 
williamr@2:   // must define assignment operator explicitly, implicit version is
williamr@2:   // illformed if HT is a reference (12.8. (12))
williamr@2:   cons& operator=(const cons& u) {
williamr@2:     head = u.head; tail = u.tail;  return *this;
williamr@2:   }
williamr@2: 
williamr@2:   template <class T1, class T2>
williamr@2:   cons& operator=( const std::pair<T1, T2>& u ) {
williamr@2:     BOOST_STATIC_ASSERT(length<cons>::value == 2); // check length = 2
williamr@2:     head = u.first; tail.head = u.second; return *this;
williamr@2:   }
williamr@2: 
williamr@2:   // get member functions (non-const and const)
williamr@2:   template <int N>
williamr@2:   typename access_traits<
williamr@2:              typename element<N, cons<HT, TT> >::type
williamr@2:            >::non_const_type
williamr@2:   get() {
williamr@2:     return boost::tuples::get<N>(*this); // delegate to non-member get
williamr@2:   }
williamr@2: 
williamr@2:   template <int N>
williamr@2:   typename access_traits<
williamr@2:              typename element<N, cons<HT, TT> >::type
williamr@2:            >::const_type
williamr@2:   get() const {
williamr@2:     return boost::tuples::get<N>(*this); // delegate to non-member get
williamr@2:   }
williamr@2: };
williamr@2: 
williamr@2: template <class HT>
williamr@2: struct cons<HT, null_type> {
williamr@2: 
williamr@2:   typedef HT head_type;
williamr@2:   typedef null_type tail_type;
williamr@2:   typedef cons<HT, null_type> self_type;
williamr@2: 
williamr@2:   typedef typename
williamr@2:     detail::wrap_non_storeable_type<head_type>::type stored_head_type;
williamr@2:   stored_head_type head;
williamr@2: 
williamr@2:   typename access_traits<stored_head_type>::non_const_type
williamr@2:   get_head() { return head; }
williamr@2: 
williamr@2:   null_type get_tail() { return null_type(); }
williamr@2: 
williamr@2:   typename access_traits<stored_head_type>::const_type
williamr@2:   get_head() const { return head; }
williamr@2: 
williamr@2:   const null_type get_tail() const { return null_type(); }
williamr@2: 
williamr@2:   //  cons() : head(detail::default_arg<HT>::f()) {}
williamr@2:   cons() : head() {}
williamr@2: 
williamr@2:   cons(typename access_traits<stored_head_type>::parameter_type h,
williamr@2:        const null_type& = null_type())
williamr@2:     : head (h) {}
williamr@2: 
williamr@2:   template<class T1>
williamr@2:   cons(T1& t1, const null_type&, const null_type&, const null_type&,
williamr@2:        const null_type&, const null_type&, const null_type&,
williamr@2:        const null_type&, const null_type&, const null_type&)
williamr@2:   : head (t1) {}
williamr@2: 
williamr@2:   cons(const null_type&,
williamr@2:        const null_type&, const null_type&, const null_type&,
williamr@2:        const null_type&, const null_type&, const null_type&,
williamr@2:        const null_type&, const null_type&, const null_type&)
williamr@2:   : head () {}
williamr@2: 
williamr@2:   template <class HT2>
williamr@2:   cons( const cons<HT2, null_type>& u ) : head(u.head) {}
williamr@2: 
williamr@2:   template <class HT2>
williamr@2:   cons& operator=(const cons<HT2, null_type>& u )
williamr@2:   { head = u.head; return *this; }
williamr@2: 
williamr@2:   // must define assignment operator explicitely, implicit version
williamr@2:   // is illformed if HT is a reference
williamr@2:   cons& operator=(const cons& u) { head = u.head; return *this; }
williamr@2: 
williamr@2:   template <int N>
williamr@2:   typename access_traits<
williamr@2:              typename element<N, self_type>::type
williamr@2:             >::non_const_type
williamr@2:   get(BOOST_EXPLICIT_TEMPLATE_NON_TYPE(int, N)) {
williamr@2:     return boost::tuples::get<N>(*this);
williamr@2:   }
williamr@2: 
williamr@2:   template <int N>
williamr@2:   typename access_traits<
williamr@2:              typename element<N, self_type>::type
williamr@2:            >::const_type
williamr@2:   get(BOOST_EXPLICIT_TEMPLATE_NON_TYPE(int, N)) const {
williamr@2:     return boost::tuples::get<N>(*this);
williamr@2:   }
williamr@2: 
williamr@2: };
williamr@2: 
williamr@2: // templates for finding out the length of the tuple -------------------
williamr@2: 
williamr@2: template<class T>
williamr@2: struct length  {
williamr@2:   BOOST_STATIC_CONSTANT(int, value = 1 + length<typename T::tail_type>::value);
williamr@2: };
williamr@2: 
williamr@2: template<>
williamr@2: struct length<tuple<> > {
williamr@2:   BOOST_STATIC_CONSTANT(int, value = 0);
williamr@2: };
williamr@2: 
williamr@2: template<>
williamr@2: struct length<null_type> {
williamr@2:   BOOST_STATIC_CONSTANT(int, value = 0);
williamr@2: };
williamr@2: 
williamr@2: 
williamr@2: namespace detail {
williamr@2: 
williamr@2: // Tuple to cons mapper --------------------------------------------------
williamr@2: template <class T0, class T1, class T2, class T3, class T4,
williamr@2:           class T5, class T6, class T7, class T8, class T9>
williamr@2: struct map_tuple_to_cons
williamr@2: {
williamr@2:   typedef cons<T0,
williamr@2:                typename map_tuple_to_cons<T1, T2, T3, T4, T5,
williamr@2:                                           T6, T7, T8, T9, null_type>::type
williamr@2:               > type;
williamr@2: };
williamr@2: 
williamr@2: // The empty tuple is a null_type
williamr@2: template <>
williamr@2: 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>
williamr@2: {
williamr@2:   typedef null_type type;
williamr@2: };
williamr@2: 
williamr@2: } // end detail
williamr@2: 
williamr@2: // -------------------------------------------------------------------
williamr@2: // -- tuple ------------------------------------------------------
williamr@2: template <class T0, class T1, class T2, class T3, class T4,
williamr@2:           class T5, class T6, class T7, class T8, class T9>
williamr@2: 
williamr@2: class tuple :
williamr@2:   public detail::map_tuple_to_cons<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>::type
williamr@2: {
williamr@2: public:
williamr@2:   typedef typename
williamr@2:     detail::map_tuple_to_cons<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>::type inherited;
williamr@2:   typedef typename inherited::head_type head_type;
williamr@2:   typedef typename inherited::tail_type tail_type;
williamr@2: 
williamr@2: 
williamr@2: // access_traits<T>::parameter_type takes non-reference types as const T&
williamr@2:   tuple() {}
williamr@2: 
williamr@2:   tuple(typename access_traits<T0>::parameter_type t0)
williamr@2:     : inherited(t0, detail::cnull(), detail::cnull(), detail::cnull(),
williamr@2:                 detail::cnull(), detail::cnull(), detail::cnull(),
williamr@2:                 detail::cnull(), detail::cnull(), detail::cnull()) {}
williamr@2: 
williamr@2:   tuple(typename access_traits<T0>::parameter_type t0,
williamr@2:         typename access_traits<T1>::parameter_type t1)
williamr@2:     : inherited(t0, t1, detail::cnull(), detail::cnull(),
williamr@2:                 detail::cnull(), detail::cnull(), detail::cnull(),
williamr@2:                 detail::cnull(), detail::cnull(), detail::cnull()) {}
williamr@2: 
williamr@2:   tuple(typename access_traits<T0>::parameter_type t0,
williamr@2:         typename access_traits<T1>::parameter_type t1,
williamr@2:         typename access_traits<T2>::parameter_type t2)
williamr@2:     : inherited(t0, t1, t2, detail::cnull(), detail::cnull(),
williamr@2:                 detail::cnull(), detail::cnull(), detail::cnull(),
williamr@2:                 detail::cnull(), detail::cnull()) {}
williamr@2: 
williamr@2:   tuple(typename access_traits<T0>::parameter_type t0,
williamr@2:         typename access_traits<T1>::parameter_type t1,
williamr@2:         typename access_traits<T2>::parameter_type t2,
williamr@2:         typename access_traits<T3>::parameter_type t3)
williamr@2:     : inherited(t0, t1, t2, t3, detail::cnull(), detail::cnull(),
williamr@2:                 detail::cnull(), detail::cnull(), detail::cnull(),
williamr@2:                 detail::cnull()) {}
williamr@2: 
williamr@2:   tuple(typename access_traits<T0>::parameter_type t0,
williamr@2:         typename access_traits<T1>::parameter_type t1,
williamr@2:         typename access_traits<T2>::parameter_type t2,
williamr@2:         typename access_traits<T3>::parameter_type t3,
williamr@2:         typename access_traits<T4>::parameter_type t4)
williamr@2:     : inherited(t0, t1, t2, t3, t4, detail::cnull(), detail::cnull(),
williamr@2:                 detail::cnull(), detail::cnull(), detail::cnull()) {}
williamr@2: 
williamr@2:   tuple(typename access_traits<T0>::parameter_type t0,
williamr@2:         typename access_traits<T1>::parameter_type t1,
williamr@2:         typename access_traits<T2>::parameter_type t2,
williamr@2:         typename access_traits<T3>::parameter_type t3,
williamr@2:         typename access_traits<T4>::parameter_type t4,
williamr@2:         typename access_traits<T5>::parameter_type t5)
williamr@2:     : inherited(t0, t1, t2, t3, t4, t5, detail::cnull(), detail::cnull(),
williamr@2:                 detail::cnull(), detail::cnull()) {}
williamr@2: 
williamr@2:   tuple(typename access_traits<T0>::parameter_type t0,
williamr@2:         typename access_traits<T1>::parameter_type t1,
williamr@2:         typename access_traits<T2>::parameter_type t2,
williamr@2:         typename access_traits<T3>::parameter_type t3,
williamr@2:         typename access_traits<T4>::parameter_type t4,
williamr@2:         typename access_traits<T5>::parameter_type t5,
williamr@2:         typename access_traits<T6>::parameter_type t6)
williamr@2:     : inherited(t0, t1, t2, t3, t4, t5, t6, detail::cnull(),
williamr@2:                 detail::cnull(), detail::cnull()) {}
williamr@2: 
williamr@2:   tuple(typename access_traits<T0>::parameter_type t0,
williamr@2:         typename access_traits<T1>::parameter_type t1,
williamr@2:         typename access_traits<T2>::parameter_type t2,
williamr@2:         typename access_traits<T3>::parameter_type t3,
williamr@2:         typename access_traits<T4>::parameter_type t4,
williamr@2:         typename access_traits<T5>::parameter_type t5,
williamr@2:         typename access_traits<T6>::parameter_type t6,
williamr@2:         typename access_traits<T7>::parameter_type t7)
williamr@2:     : inherited(t0, t1, t2, t3, t4, t5, t6, t7, detail::cnull(),
williamr@2:                 detail::cnull()) {}
williamr@2: 
williamr@2:   tuple(typename access_traits<T0>::parameter_type t0,
williamr@2:         typename access_traits<T1>::parameter_type t1,
williamr@2:         typename access_traits<T2>::parameter_type t2,
williamr@2:         typename access_traits<T3>::parameter_type t3,
williamr@2:         typename access_traits<T4>::parameter_type t4,
williamr@2:         typename access_traits<T5>::parameter_type t5,
williamr@2:         typename access_traits<T6>::parameter_type t6,
williamr@2:         typename access_traits<T7>::parameter_type t7,
williamr@2:         typename access_traits<T8>::parameter_type t8)
williamr@2:     : inherited(t0, t1, t2, t3, t4, t5, t6, t7, t8, detail::cnull()) {}
williamr@2: 
williamr@2:   tuple(typename access_traits<T0>::parameter_type t0,
williamr@2:         typename access_traits<T1>::parameter_type t1,
williamr@2:         typename access_traits<T2>::parameter_type t2,
williamr@2:         typename access_traits<T3>::parameter_type t3,
williamr@2:         typename access_traits<T4>::parameter_type t4,
williamr@2:         typename access_traits<T5>::parameter_type t5,
williamr@2:         typename access_traits<T6>::parameter_type t6,
williamr@2:         typename access_traits<T7>::parameter_type t7,
williamr@2:         typename access_traits<T8>::parameter_type t8,
williamr@2:         typename access_traits<T9>::parameter_type t9)
williamr@2:     : inherited(t0, t1, t2, t3, t4, t5, t6, t7, t8, t9) {}
williamr@2: 
williamr@2: 
williamr@2:   template<class U1, class U2>
williamr@2:   tuple(const cons<U1, U2>& p) : inherited(p) {}
williamr@2: 
williamr@2:   template <class U1, class U2>
williamr@2:   tuple& operator=(const cons<U1, U2>& k) {
williamr@2:     inherited::operator=(k);
williamr@2:     return *this;
williamr@2:   }
williamr@2: 
williamr@2:   template <class U1, class U2>
williamr@2:   tuple& operator=(const std::pair<U1, U2>& k) {
williamr@2:     BOOST_STATIC_ASSERT(length<tuple>::value == 2);// check_length = 2
williamr@2:     this->head = k.first;
williamr@2:     this->tail.head = k.second;
williamr@2:     return *this;
williamr@2:   }
williamr@2: 
williamr@2: };
williamr@2: 
williamr@2: // The empty tuple
williamr@2: template <>
williamr@2: class tuple<null_type, null_type, null_type, null_type, null_type, null_type, null_type, null_type, null_type, null_type>  :
williamr@2:   public null_type
williamr@2: {
williamr@2: public:
williamr@2:   typedef null_type inherited;
williamr@2: };
williamr@2: 
williamr@2: 
williamr@2: // Swallows any assignment   (by Doug Gregor)
williamr@2: namespace detail {
williamr@2: 
williamr@2: struct swallow_assign {
williamr@2: 
williamr@2:   template<typename T>
williamr@2:   swallow_assign const& operator=(const T&) const {
williamr@2:     return *this;
williamr@2:   }
williamr@2: };
williamr@2: 
williamr@2: } // namespace detail
williamr@2: 
williamr@2: // "ignore" allows tuple positions to be ignored when using "tie".
williamr@2: detail::swallow_assign const ignore = detail::swallow_assign();
williamr@2: 
williamr@2: // ---------------------------------------------------------------------------
williamr@2: // The call_traits for make_tuple
williamr@2: // Honours the reference_wrapper class.
williamr@2: 
williamr@2: // Must be instantiated with plain or const plain types (not with references)
williamr@2: 
williamr@2: // from template<class T> foo(const T& t) : make_tuple_traits<const T>::type
williamr@2: // from template<class T> foo(T& t) : make_tuple_traits<T>::type
williamr@2: 
williamr@2: // Conversions:
williamr@2: // T -> T,
williamr@2: // references -> compile_time_error
williamr@2: // reference_wrapper<T> -> T&
williamr@2: // const reference_wrapper<T> -> T&
williamr@2: // array -> const ref array
williamr@2: 
williamr@2: 
williamr@2: template<class T>
williamr@2: struct make_tuple_traits {
williamr@2:   typedef T type;
williamr@2: 
williamr@2:   // commented away, see below  (JJ)
williamr@2:   //  typedef typename IF<
williamr@2:   //  boost::is_function<T>::value,
williamr@2:   //  T&,
williamr@2:   //  T>::RET type;
williamr@2: 
williamr@2: };
williamr@2: 
williamr@2: // The is_function test was there originally for plain function types,
williamr@2: // which can't be stored as such (we must either store them as references or
williamr@2: // pointers). Such a type could be formed if make_tuple was called with a
williamr@2: // reference to a function.
williamr@2: // But this would mean that a const qualified function type was formed in
williamr@2: // the make_tuple function and hence make_tuple can't take a function
williamr@2: // reference as a parameter, and thus T can't be a function type.
williamr@2: // So is_function test was removed.
williamr@2: // (14.8.3. says that type deduction fails if a cv-qualified function type
williamr@2: // is created. (It only applies for the case of explicitly specifying template
williamr@2: // args, though?)) (JJ)
williamr@2: 
williamr@2: template<class T>
williamr@2: struct make_tuple_traits<T&> {
williamr@2:   typedef typename
williamr@2:      detail::generate_error<T&>::
williamr@2:        do_not_use_with_reference_type error;
williamr@2: };
williamr@2: 
williamr@2: // Arrays can't be stored as plain types; convert them to references.
williamr@2: // All arrays are converted to const. This is because make_tuple takes its
williamr@2: // parameters as const T& and thus the knowledge of the potential
williamr@2: // non-constness of actual argument is lost.
williamr@2: template<class T, int n>  struct make_tuple_traits <T[n]> {
williamr@2:   typedef const T (&type)[n];
williamr@2: };
williamr@2: 
williamr@2: template<class T, int n>
williamr@2: struct make_tuple_traits<const T[n]> {
williamr@2:   typedef const T (&type)[n];
williamr@2: };
williamr@2: 
williamr@2: template<class T, int n>  struct make_tuple_traits<volatile T[n]> {
williamr@2:   typedef const volatile T (&type)[n];
williamr@2: };
williamr@2: 
williamr@2: template<class T, int n>
williamr@2: struct make_tuple_traits<const volatile T[n]> {
williamr@2:   typedef const volatile T (&type)[n];
williamr@2: };
williamr@2: 
williamr@2: template<class T>
williamr@2: struct make_tuple_traits<reference_wrapper<T> >{
williamr@2:   typedef T& type;
williamr@2: };
williamr@2: 
williamr@2: template<class T>
williamr@2: struct make_tuple_traits<const reference_wrapper<T> >{
williamr@2:   typedef T& type;
williamr@2: };
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: namespace detail {
williamr@2: 
williamr@2: // a helper traits to make the make_tuple functions shorter (Vesa Karvonen's
williamr@2: // suggestion)
williamr@2: template <
williamr@2:   class T0 = null_type, class T1 = null_type, class T2 = null_type,
williamr@2:   class T3 = null_type, class T4 = null_type, class T5 = null_type,
williamr@2:   class T6 = null_type, class T7 = null_type, class T8 = null_type,
williamr@2:   class T9 = null_type
williamr@2: >
williamr@2: struct make_tuple_mapper {
williamr@2:   typedef
williamr@2:     tuple<typename make_tuple_traits<T0>::type,
williamr@2:           typename make_tuple_traits<T1>::type,
williamr@2:           typename make_tuple_traits<T2>::type,
williamr@2:           typename make_tuple_traits<T3>::type,
williamr@2:           typename make_tuple_traits<T4>::type,
williamr@2:           typename make_tuple_traits<T5>::type,
williamr@2:           typename make_tuple_traits<T6>::type,
williamr@2:           typename make_tuple_traits<T7>::type,
williamr@2:           typename make_tuple_traits<T8>::type,
williamr@2:           typename make_tuple_traits<T9>::type> type;
williamr@2: };
williamr@2: 
williamr@2: } // end detail
williamr@2: 
williamr@2: // -make_tuple function templates -----------------------------------
williamr@2: inline tuple<> make_tuple() {
williamr@2:   return tuple<>();
williamr@2: }
williamr@2: 
williamr@2: template<class T0>
williamr@2: inline typename detail::make_tuple_mapper<T0>::type
williamr@2: make_tuple(const T0& t0) {
williamr@2:   typedef typename detail::make_tuple_mapper<T0>::type t;
williamr@2:   return t(t0);
williamr@2: }
williamr@2: 
williamr@2: template<class T0, class T1>
williamr@2: inline typename detail::make_tuple_mapper<T0, T1>::type
williamr@2: make_tuple(const T0& t0, const T1& t1) {
williamr@2:   typedef typename detail::make_tuple_mapper<T0, T1>::type t;
williamr@2:   return t(t0, t1);
williamr@2: }
williamr@2: 
williamr@2: template<class T0, class T1, class T2>
williamr@2: inline typename detail::make_tuple_mapper<T0, T1, T2>::type
williamr@2: make_tuple(const T0& t0, const T1& t1, const T2& t2) {
williamr@2:   typedef typename detail::make_tuple_mapper<T0, T1, T2>::type t;
williamr@2:   return t(t0, t1, t2);
williamr@2: }
williamr@2: 
williamr@2: template<class T0, class T1, class T2, class T3>
williamr@2: inline typename detail::make_tuple_mapper<T0, T1, T2, T3>::type
williamr@2: make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3) {
williamr@2:   typedef typename detail::make_tuple_mapper<T0, T1, T2, T3>::type t;
williamr@2:   return t(t0, t1, t2, t3);
williamr@2: }
williamr@2: 
williamr@2: template<class T0, class T1, class T2, class T3, class T4>
williamr@2: inline typename detail::make_tuple_mapper<T0, T1, T2, T3, T4>::type
williamr@2: make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3,
williamr@2:                   const T4& t4) {
williamr@2:   typedef typename detail::make_tuple_mapper<T0, T1, T2, T3, T4>::type t;
williamr@2:   return t(t0, t1, t2, t3, t4);
williamr@2: }
williamr@2: 
williamr@2: template<class T0, class T1, class T2, class T3, class T4, class T5>
williamr@2: inline typename detail::make_tuple_mapper<T0, T1, T2, T3, T4, T5>::type
williamr@2: make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3,
williamr@2:                   const T4& t4, const T5& t5) {
williamr@2:   typedef typename detail::make_tuple_mapper<T0, T1, T2, T3, T4, T5>::type t;
williamr@2:   return t(t0, t1, t2, t3, t4, t5);
williamr@2: }
williamr@2: 
williamr@2: template<class T0, class T1, class T2, class T3, class T4, class T5, class T6>
williamr@2: inline typename detail::make_tuple_mapper<T0, T1, T2, T3, T4, T5, T6>::type
williamr@2: make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3,
williamr@2:                   const T4& t4, const T5& t5, const T6& t6) {
williamr@2:   typedef typename detail::make_tuple_mapper
williamr@2:            <T0, T1, T2, T3, T4, T5, T6>::type t;
williamr@2:   return t(t0, t1, t2, t3, t4, t5, t6);
williamr@2: }
williamr@2: 
williamr@2: template<class T0, class T1, class T2, class T3, class T4, class T5, class T6,
williamr@2:          class T7>
williamr@2: inline typename detail::make_tuple_mapper<T0, T1, T2, T3, T4, T5, T6, T7>::type
williamr@2: make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3,
williamr@2:                   const T4& t4, const T5& t5, const T6& t6, const T7& t7) {
williamr@2:   typedef typename detail::make_tuple_mapper
williamr@2:            <T0, T1, T2, T3, T4, T5, T6, T7>::type t;
williamr@2:   return t(t0, t1, t2, t3, t4, t5, t6, t7);
williamr@2: }
williamr@2: 
williamr@2: template<class T0, class T1, class T2, class T3, class T4, class T5, class T6,
williamr@2:          class T7, class T8>
williamr@2: inline typename detail::make_tuple_mapper
williamr@2:   <T0, T1, T2, T3, T4, T5, T6, T7, T8>::type
williamr@2: make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3,
williamr@2:                   const T4& t4, const T5& t5, const T6& t6, const T7& t7,
williamr@2:                   const T8& t8) {
williamr@2:   typedef typename detail::make_tuple_mapper
williamr@2:            <T0, T1, T2, T3, T4, T5, T6, T7, T8>::type t;
williamr@2:   return t(t0, t1, t2, t3, t4, t5, t6, t7, t8);
williamr@2: }
williamr@2: 
williamr@2: template<class T0, class T1, class T2, class T3, class T4, class T5, class T6,
williamr@2:          class T7, class T8, class T9>
williamr@2: inline typename detail::make_tuple_mapper
williamr@2:   <T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>::type
williamr@2: make_tuple(const T0& t0, const T1& t1, const T2& t2, const T3& t3,
williamr@2:                   const T4& t4, const T5& t5, const T6& t6, const T7& t7,
williamr@2:                   const T8& t8, const T9& t9) {
williamr@2:   typedef typename detail::make_tuple_mapper
williamr@2:            <T0, T1, T2, T3, T4, T5, T6, T7, T8, T9>::type t;
williamr@2:   return t(t0, t1, t2, t3, t4, t5, t6, t7, t8, t9);
williamr@2: }
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: // Tie function templates -------------------------------------------------
williamr@2: template<class T1>
williamr@2: inline tuple<T1&> tie(T1& t1) {
williamr@2:   return tuple<T1&> (t1);
williamr@2: }
williamr@2: 
williamr@2: template<class T1, class T2>
williamr@2: inline tuple<T1&, T2&> tie(T1& t1, T2& t2) {
williamr@2:   return tuple<T1&, T2&> (t1, t2);
williamr@2: }
williamr@2: 
williamr@2: template<class T1, class T2, class T3>
williamr@2: inline tuple<T1&, T2&, T3&> tie(T1& t1, T2& t2, T3& t3) {
williamr@2:   return tuple<T1&, T2&, T3&> (t1, t2, t3);
williamr@2: }
williamr@2: 
williamr@2: template<class T1, class T2, class T3, class T4>
williamr@2: inline tuple<T1&, T2&, T3&, T4&> tie(T1& t1, T2& t2, T3& t3, T4& t4) {
williamr@2:   return tuple<T1&, T2&, T3&, T4&> (t1, t2, t3, t4);
williamr@2: }
williamr@2: 
williamr@2: template<class T1, class T2, class T3, class T4, class T5>
williamr@2: inline tuple<T1&, T2&, T3&, T4&, T5&>
williamr@2: tie(T1& t1, T2& t2, T3& t3, T4& t4, T5& t5) {
williamr@2:   return tuple<T1&, T2&, T3&, T4&, T5&> (t1, t2, t3, t4, t5);
williamr@2: }
williamr@2: 
williamr@2: template<class T1, class T2, class T3, class T4, class T5, class T6>
williamr@2: inline tuple<T1&, T2&, T3&, T4&, T5&, T6&>
williamr@2: tie(T1& t1, T2& t2, T3& t3, T4& t4, T5& t5, T6& t6) {
williamr@2:   return tuple<T1&, T2&, T3&, T4&, T5&, T6&> (t1, t2, t3, t4, t5, t6);
williamr@2: }
williamr@2: 
williamr@2: template<class T1, class T2, class T3, class T4, class T5, class T6, class T7>
williamr@2: inline tuple<T1&, T2&, T3&, T4&, T5&, T6&, T7&>
williamr@2: tie(T1& t1, T2& t2, T3& t3, T4& t4, T5& t5, T6& t6, T7& t7) {
williamr@2:   return tuple<T1&, T2&, T3&, T4&, T5&, T6&, T7&> (t1, t2, t3, t4, t5, t6, t7);
williamr@2: }
williamr@2: 
williamr@2: template<class T1, class T2, class T3, class T4, class T5, class T6, class T7,
williamr@2:          class T8>
williamr@2: inline tuple<T1&, T2&, T3&, T4&, T5&, T6&, T7&, T8&>
williamr@2: tie(T1& t1, T2& t2, T3& t3, T4& t4, T5& t5, T6& t6, T7& t7, T8& t8) {
williamr@2:   return tuple<T1&, T2&, T3&, T4&, T5&, T6&, T7&, T8&>
williamr@2:            (t1, t2, t3, t4, t5, t6, t7, t8);
williamr@2: }
williamr@2: 
williamr@2: template<class T1, class T2, class T3, class T4, class T5, class T6, class T7,
williamr@2:          class T8, class T9>
williamr@2: inline tuple<T1&, T2&, T3&, T4&, T5&, T6&, T7&, T8&, T9&>
williamr@2: tie(T1& t1, T2& t2, T3& t3, T4& t4, T5& t5, T6& t6, T7& t7, T8& t8,
williamr@2:            T9& t9) {
williamr@2:   return tuple<T1&, T2&, T3&, T4&, T5&, T6&, T7&, T8&, T9&>
williamr@2:             (t1, t2, t3, t4, t5, t6, t7, t8, t9);
williamr@2: }
williamr@2: 
williamr@2: template<class T1, class T2, class T3, class T4, class T5, class T6, class T7,
williamr@2:          class T8, class T9, class T10>
williamr@2: inline tuple<T1&, T2&, T3&, T4&, T5&, T6&, T7&, T8&, T9&, T10&>
williamr@2: tie(T1& t1, T2& t2, T3& t3, T4& t4, T5& t5, T6& t6, T7& t7, T8& t8,
williamr@2:            T9& t9, T10& t10) {
williamr@2:   return tuple<T1&, T2&, T3&, T4&, T5&, T6&, T7&, T8&, T9&, T10&>
williamr@2:            (t1, t2, t3, t4, t5, t6, t7, t8, t9, t10);
williamr@2: }
williamr@2: 
williamr@2: } // end of namespace tuples
williamr@2: } // end of namespace boost
williamr@2: 
williamr@2: 
williamr@2: #endif // BOOST_TUPLE_BASIC_HPP
williamr@2: 
williamr@2: