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Subject: [Boost-commit] svn:boost r78481 - in sandbox/type_erasure/boost/type_erasure: . detail
From: steven_at_[hidden]
Date: 2012-05-15 12:29:56


Author: steven_watanabe
Date: 2012-05-15 12:29:55 EDT (Tue, 15 May 2012)
New Revision: 78481
URL: http://svn.boost.org/trac/boost/changeset/78481

Log:
Variadic template implementation of tuple.
Text files modified:
   sandbox/type_erasure/boost/type_erasure/detail/rebind_placeholders.hpp | 8
   sandbox/type_erasure/boost/type_erasure/tuple.hpp | 316 ++++++++++++++++++++++++++++++++++++---
   2 files changed, 293 insertions(+), 31 deletions(-)

Modified: sandbox/type_erasure/boost/type_erasure/detail/rebind_placeholders.hpp
==============================================================================
--- sandbox/type_erasure/boost/type_erasure/detail/rebind_placeholders.hpp (original)
+++ sandbox/type_erasure/boost/type_erasure/detail/rebind_placeholders.hpp 2012-05-15 12:29:55 EDT (Tue, 15 May 2012)
@@ -41,6 +41,12 @@
     typedef void type;
 };
 
+template<class T>
+struct identity
+{
+ typedef T type;
+};
+
 template<class T, class Bindings>
 struct rebind_placeholders_in_argument
 {
@@ -51,7 +57,7 @@
     typedef typename ::boost::mpl::eval_if<
         ::boost::type_erasure::is_placeholder<T>,
         ::boost::mpl::at<Bindings, T>,
- ::boost::mpl::identity<T>
+ ::boost::type_erasure::detail::identity<T>
>::type type;
 };
 

Modified: sandbox/type_erasure/boost/type_erasure/tuple.hpp
==============================================================================
--- sandbox/type_erasure/boost/type_erasure/tuple.hpp (original)
+++ sandbox/type_erasure/boost/type_erasure/tuple.hpp 2012-05-15 12:29:55 EDT (Tue, 15 May 2012)
@@ -1,6 +1,6 @@
 // Boost.TypeErasure library
 //
-// Copyright 2011 Steven Watanabe
+// Copyright 2011-2012 Steven Watanabe
 //
 // Distributed under the Boost Software License Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -13,6 +13,289 @@
 #ifndef BOOST_TYPE_ERASURE_TUPLE_HPP_INCLUDED
 #define BOOST_TYPE_ERASURE_TUPLE_HPP_INCLUDED
 
+#include <boost/config.hpp>
+
+
+#ifdef BOOST_TYPE_ERASURE_DOXYGEN
+
+/**
+ * @ref tuple is a Boost.Fusion Random Access Sequence containing
+ * @ref any "anys". Concept is interpreted in the same way as for
+ * @ref any. The remaining arguments must be (possibly const
+ * and/or reference qualified) placeholders.
+ */
+template<class Concept, class... T>
+class tuple
+{
+public:
+ /**
+ * Constructs a tuple. Each element of @c args will
+ * be used to initialize the corresponding member.
+ */
+ template<class... U>
+ explicit tuple(U&&... args);
+};
+
+template<int N, class Concept, class... T>
+any<Concept, TN>& get(tuple<Concept, T...>& arg);
+template<int N, class Concept, class... T>
+const any<Concept, TN>& get(const tuple<Concept, T...>& arg);
+
+#elif !defined(BOOST_NO_VARIADIC_TEMPLATES) && !defined(BOOST_NO_RVALUE_REFERENCES)
+
+#include <boost/mpl/int.hpp>
+#include <boost/mpl/bool.hpp>
+#include <boost/mpl/map.hpp>
+#include <boost/mpl/insert.hpp>
+#include <boost/type_traits/remove_reference.hpp>
+#include <boost/type_traits/remove_const.hpp>
+#include <boost/fusion/include/category_of.hpp>
+#include <boost/fusion/include/iterator_facade.hpp>
+#include <boost/fusion/include/sequence_facade.hpp>
+#include <boost/type_erasure/any.hpp>
+#include <boost/type_erasure/static_binding.hpp>
+#include <boost/type_erasure/config.hpp>
+
+namespace boost {
+namespace type_erasure {
+
+template<class Concept, class... T>
+struct cons;
+
+template<class Concept>
+struct cons<Concept>
+{
+ template<class Binding>
+ cons(const Binding&) {}
+};
+
+template<class Concept, class T0, class... T>
+struct cons<Concept, T0, T...>
+{
+ typedef any<Concept, T0> value_type;
+ typedef cons<Concept, T...> rest_type;
+ template<class Binding, class U0, class... U>
+ cons(const Binding& b, U0&& u0, U&&... u)
+ : value(std::forward<U0>(u0), b),
+ rest(b, std::forward<U>(u)...)
+ {}
+ any<Concept, T0> value;
+ cons<Concept, T...> rest;
+};
+
+namespace detail {
+
+template<int N, class Cons>
+struct cons_advance
+{
+ typedef typename cons_advance<N-1, Cons>::type::rest_type type;
+ static const type& call(const Cons& c)
+ {
+ return cons_advance<N-1, Cons>::call(c).rest;
+ }
+};
+
+template<class Cons>
+struct cons_advance<0, Cons>
+{
+ typedef Cons type;
+ static const type& call(const Cons& c)
+ {
+ return c;
+ }
+};
+
+template<class... T>
+struct make_map;
+
+template<class T0, class... T>
+struct make_map<T0, T...>
+{
+ typedef typename ::boost::mpl::insert<
+ typename ::boost::type_erasure::detail::make_map<T...>::type,
+ T0
+ >::type type;
+};
+
+template<>
+struct make_map<>
+{
+ typedef ::boost::mpl::map0<> type;
+};
+
+}
+
+/** INTERNAL ONLY */
+template<class Tuple, int N>
+class tuple_iterator :
+ public ::boost::fusion::iterator_facade<
+ tuple_iterator<Tuple, N>,
+ ::boost::fusion::random_access_traversal_tag
+ >
+{
+public:
+ typedef ::boost::mpl::int_<N> index;
+ explicit tuple_iterator(Tuple& t_arg) : t(&t_arg) {}
+ template<class It>
+ struct value_of
+ {
+ typedef typename Tuple::template value_at<Tuple, mpl::int_<N> >::type type;
+ };
+ template<class It>
+ struct deref
+ {
+ typedef typename Tuple::template at<Tuple, mpl::int_<N> >::type type;
+ static type call(It it)
+ {
+ return Tuple::template at<Tuple, mpl::int_<N> >::call(*it.t);
+ }
+ };
+ template<class It, class M>
+ struct advance
+ {
+ typedef tuple_iterator<Tuple, (It::index::value+M::value)> type;
+ static type call(It it) { return type(*it.t); }
+ };
+ template<class It>
+ struct next : advance<It, ::boost::mpl::int_<1> > {};
+ template<class It>
+ struct prior : advance<It, ::boost::mpl::int_<-1> > {};
+ template<class It1, class It2>
+ struct distance
+ {
+ typedef typename ::boost::mpl::minus<
+ typename It2::index,
+ typename It1::index
+ >::type type;
+ static type call(It1, It2) { return type(); }
+ };
+private:
+ Tuple* t;
+};
+
+template<class Concept, class... T>
+class tuple :
+ public ::boost::fusion::sequence_facade<
+ ::boost::type_erasure::tuple<Concept, T...>,
+ ::boost::fusion::forward_traversal_tag
+ >
+{
+public:
+ template<class... U>
+ explicit tuple(U&&... args)
+ : impl(
+ ::boost::type_erasure::make_binding<
+ typename ::boost::type_erasure::detail::make_map<
+ ::boost::mpl::pair<
+ typename ::boost::remove_const<
+ typename ::boost::remove_reference<T>::type
+ >::type,
+ typename ::boost::remove_const<
+ typename ::boost::remove_reference<U>::type
+ >::type
+ >...
+ >::type
+ >(),
+ std::forward<U>(args)...)
+ {}
+
+ template<class Seq>
+ struct begin
+ {
+ typedef ::boost::type_erasure::tuple_iterator<
+ Seq,
+ 0
+ > type;
+ static type call(Seq& seq) { return type(seq); }
+ };
+ template<class Seq>
+ struct end
+ {
+ typedef ::boost::type_erasure::tuple_iterator<
+ Seq,
+ sizeof...(T)
+ > type;
+ static type call(Seq& seq) { return type(seq); }
+ };
+ template<class Seq>
+ struct size
+ {
+ typedef ::boost::mpl::int_<sizeof...(T)> type;
+ static type call(Seq& seq) { return type(); }
+ };
+ template<class Seq>
+ struct empty
+ {
+ typedef ::boost::mpl::bool_<sizeof...(T) == 0> type;
+ static type call(Seq& seq) { return type(); }
+ };
+ template<class Seq, class N>
+ struct at
+ {
+ typedef typename ::boost::type_erasure::detail::cons_advance<
+ N::value,
+ ::boost::type_erasure::cons<Concept, T...>
+ >::type::value_type value_type;
+ typedef typename ::boost::mpl::if_< ::boost::is_const<Seq>,
+ const value_type&,
+ value_type&
+ >::type type;
+ static type call(Seq& seq)
+ {
+ return const_cast<type>(
+ ::boost::type_erasure::detail::cons_advance<
+ N::value,
+ ::boost::type_erasure::cons<Concept, T...>
+ >::call(seq.impl).value
+ );
+ }
+ };
+ template<class Seq, class N>
+ struct value_at
+ {
+ typedef typename ::boost::type_erasure::detail::cons_advance<
+ N::value,
+ ::boost::type_erasure::cons<Concept, T...>
+ >::type::value_type value_type;
+ };
+ ::boost::type_erasure::cons<Concept, T...> impl;
+};
+
+template<int N, class Concept, class... T>
+typename ::boost::type_erasure::detail::cons_advance<
+ N,
+ ::boost::type_erasure::cons<Concept, T...>
+>::type::value_type& get(::boost::type_erasure::tuple<Concept, T...>& t)
+{
+ return const_cast<
+ typename ::boost::type_erasure::detail::cons_advance<
+ N,
+ ::boost::type_erasure::cons<Concept, T...>
+ >::type::value_type&
+ >(
+ ::boost::type_erasure::detail::cons_advance<N,
+ ::boost::type_erasure::cons<Concept, T...>
+ >::call(t.impl).value
+ );
+}
+
+template<int N, class Concept, class... T>
+const typename ::boost::type_erasure::detail::cons_advance<
+ N,
+ ::boost::type_erasure::cons<Concept, T...>
+>::type::value_type& get(const ::boost::type_erasure::tuple<Concept, T...>& t)
+{
+ return ::boost::type_erasure::detail::cons_advance<
+ N,
+ ::boost::type_erasure::cons<Concept, T...>
+ >::call(t.impl).value;
+}
+
+}
+}
+
+#else
+
 #include <boost/mpl/int.hpp>
 #include <boost/mpl/minus.hpp>
 #include <boost/mpl/equal_to.hpp>
@@ -159,33 +442,6 @@
     };
 };
 
-#ifdef BOOST_TYPE_ERASURE_DOXYGEN
-
-/**
- * @ref tuple is a Boost.Fusion Random Access Sequence containing
- * @ref any "anys". Concept is interpreted in the same way as for
- * @ref any. The remaining arguments must be (possibly const
- * and/or reference qualified) placeholders.
- */
-template<class Concept, class... T>
-class tuple
-{
-public:
- /**
- * Constructs a tuple. Each element of @c args will
- * be used to initialize the corresponding member.
- */
- template<class... U>
- explicit tuple(U&&... args);
-};
-
-template<int N, class Concept, class... T>
-any<Concept, TN>& get(tuple<Concept, T...>& arg);
-template<int N, class Concept, class... T>
-const any<Concept, TN>& get(const tuple<Concept, T...>& arg);
-
-#else
-
 template<class Concept,
     BOOST_PP_ENUM_PARAMS_WITH_A_DEFAULT(
         BOOST_TYPE_ERASURE_MAX_TUPLE_SIZE, class T, ::boost::type_erasure::na)>
@@ -242,8 +498,6 @@
>
>::call(arg);
 }
-
-#endif
     
 /** INTERNAL ONLY */
 #define BOOST_PP_FILENAME_1 <boost/type_erasure/tuple.hpp>
@@ -256,6 +510,8 @@
 
 #endif
 
+#endif
+
 #else
 
 #define N BOOST_PP_ITERATION()


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