Moved pointer parameter

[SVN r9348]

include/boost/counting_iterator.hpp

@@ -0,0 +1,215 @@
+// (C) Copyright David Abrahams and Jeremy Siek 2000-2001. Permission to copy,
+// use, modify, sell and distribute this software is granted provided this
+// copyright notice appears in all copies. This software is provided "as is"
+// without express or implied warranty, and with no claim as to its suitability
+// for any purpose.
+//
+// See http://www.boost.org for most recent version including documentation.
+//
+// Supplies:
+//
+//   template <class Incrementable> class counting_iterator_traits;
+//   template <class Incrementable> class counting_iterator_policies;
+//
+//     Iterator traits and policies for adapted iterators whose dereferenced
+//     value progresses through consecutive values of Incrementable when the
+//     iterator is derferenced.
+//
+//   template <class Incrementable> struct counting_iterator_generator;
+//
+//     A "type generator" whose nested type "type" is a counting iterator as
+//     described above.
+//
+//   template <class Incrementable>
+//     typename counting_iterator_generator<Incrementable>::type
+//     make_counting_iterator(Incrementable);
+//
+//     A function which produces an adapted counting iterator over values of
+//     Incrementable.
+// 
+// Revision History
+// 14 Feb 2001  Removed unnecessary typedefs from counting_iterator_traits
+//              (Jeremy Siek)
+// 11 Feb 2001  Use BOOST_STATIC_CONSTANT (Dave Abrahams)
+// 11 Feb 2001  Clean up after John Maddocks's (finally effective!) Borland
+//              fixes (David Abrahams).
+// 10 Feb 2001  Use new iterator_adaptor<> interface (David Abrahams)
+// 10 Feb 2001  Rolled in supposed Borland fixes from John Maddock, but not
+//              seeing any improvement yet (David Abrahams)
+// 09 Feb 2001  Factored out is_numeric computation. Borland still
+//              unhappy :( (David Abrahams)
+// 08 Feb 2001  Beginning of a failed attempt to appease Borland
+//              (David Abrahams)
+// 07 Feb 2001  rename counting_iterator() -> make_counting_iterator()
+//              (David Abrahams)        
+// 04 Feb 2001  Added counting_iterator_generator; updated comments
+//              (David Abrahams)
+// 24 Jan 2001  initial revision, based on Jeremy Siek's
+//              boost/pending/integer_range.hpp (David Abrahams)
+
+#ifndef BOOST_COUNTING_ITERATOR_HPP_DWA20000119
+# define BOOST_COUNTING_ITERATOR_HPP_DWA20000119
+
+# include <boost/config.hpp>
+# include <boost/detail/iterator.hpp>
+# include <boost/iterator_adaptors.hpp>
+# include <boost/type_traits.hpp>
+# include <boost/detail/numeric_traits.hpp>
+# include <boost/static_assert.hpp>
+# ifndef BOOST_NO_LIMITS
+#  include <limits>
+# endif
+
+namespace boost {
+
+namespace detail {
+
+  // Template class counting_iterator_traits_select -- choose an
+  // iterator_category and difference_type for a counting_iterator at
+  // compile-time based on whether or not it wraps an integer or an iterator,
+  // using "poor man's partial specialization".
+  template <bool is_integer> struct counting_iterator_traits_select;
+
+  // Incrementable is an iterator type
+  template <>
+  struct counting_iterator_traits_select<false>
+  {
+      template <class Incrementable>
+      struct traits
+      {
+       private:
+          typedef boost::detail::iterator_traits<Incrementable> x;
+       public:
+          typedef typename x::iterator_category iterator_category;
+          typedef typename x::difference_type difference_type;
+      };
+  };
+
+  // Incrementable is a numeric type
+  template <>
+  struct counting_iterator_traits_select<true>
+  {
+      template <class Incrementable>
+      struct traits
+      {
+          typedef typename
+            boost::detail::numeric_traits<Incrementable>::difference_type
+          difference_type;
+          typedef std::random_access_iterator_tag iterator_category;
+      };
+  };
+
+  // Template class distance_policy_select -- choose a policy for computing the
+  // distance between counting_iterators at compile-time based on whether or not
+  // the iterator wraps an integer or an iterator, using "poor man's partial
+  // specialization".
+
+  template <bool is_integer> struct distance_policy_select;
+
+  // A policy for wrapped iterators
+  template <>
+  struct distance_policy_select<false>
+  {
+      template <class Distance, class Incrementable>
+      struct policy {
+          static Distance distance(Incrementable x, Incrementable y)
+              { return boost::detail::distance(x, y); }
+      };
+  };
+
+  // A policy for wrapped numbers
+  template <>
+  struct distance_policy_select<true>
+  {
+      template <class Distance, class Incrementable>
+      struct policy {
+          static Distance distance(Incrementable x, Incrementable y)
+              { return numeric_distance(x, y); }
+      };
+  };
+
+  // Try to detect numeric types at compile time in ways compatible with the
+  // limitations of the compiler and library.
+  template <class T>
+  struct is_numeric {
+    // For a while, this wasn't true, but we rely on it below. This is a regression assert.
+    BOOST_STATIC_ASSERT(::boost::is_integral<char>::value);
+# ifndef BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS
+    BOOST_STATIC_CONSTANT(bool, value = std::numeric_limits<T>::is_specialized);
+# else
+#  if !defined(__BORLANDC__)
+    BOOST_STATIC_CONSTANT(bool, value = (
+        boost::is_convertible<int,T>::value && boost::is_convertible<T,int>::value));
+#  else
+    BOOST_STATIC_CONSTANT(bool, value = ::boost::is_arithmetic<T>::value);
+#  endif
+# endif
+  };
+
+  // Compute the distance over arbitrary numeric and/or iterator types
+  template <class Distance, class Incrementable>
+  Distance any_distance(Incrementable start, Incrementable finish, Distance* = 0)
+  {
+    
+      return distance_policy_select<(
+          is_numeric<Incrementable>::value)>::template
+          policy<Distance, Incrementable>::distance(start, finish);
+  }
+  
+} // namespace detail
+
+template <class Incrementable>
+struct counting_iterator_traits {
+ private:
+    typedef ::boost::detail::counting_iterator_traits_select<(
+        ::boost::detail::is_numeric<Incrementable>::value
+        )> binder;
+    typedef typename binder::template traits<Incrementable> traits;
+ public:
+    typedef typename traits::difference_type difference_type;
+    typedef typename traits::iterator_category iterator_category;
+};
+
+template <class Incrementable>
+struct counting_iterator_policies : public default_iterator_policies
+{
+    const Incrementable& dereference(type<const Incrementable&>, const Incrementable& i) const
+        { return i; }
+
+    template <class Difference, class Iterator1, class Iterator2>
+    Difference distance(type<Difference>, const Iterator1& x,
+                        const Iterator2& y) const
+    {
+        return boost::detail::any_distance<Difference>(x, y);//,(Difference*)());
+    }
+};
+
+// A type generator for counting iterators
+template <class Incrementable>
+struct counting_iterator_generator
+{
+    typedef counting_iterator_traits<Incrementable> traits;
+    
+    typedef iterator_adaptor<Incrementable,
+        counting_iterator_policies<Incrementable>,
+        Incrementable,
+        const Incrementable&,
+        typename traits::iterator_category,
+        typename traits::difference_type,
+        const Incrementable*
+    > type;
+};
+
+// Manufacture a counting iterator for an arbitrary incrementable type
+template <class Incrementable>
+inline typename counting_iterator_generator<Incrementable>::type
+make_counting_iterator(Incrementable x)
+{
+  typedef typename counting_iterator_generator<Incrementable>::type result_t;
+  return result_t(x);
+}
+
+
+} // namespace boost
+
+#endif // BOOST_COUNTING_ITERATOR_HPP_DWA20000119