Move from boost-sanbox [ JDG ]

[SVN r18958]

include/boost/iterator/permutation_iterator.hpp

@@ -0,0 +1,92 @@
+// (C) Copyright Toon Knapen    2001.
+// (C) Copyright David Abrahams 2003.
+// (C) Copyright Roland Richter 2003.
+// 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.
+
+#ifndef BOOST_PERMUTATION_ITERATOR_HPP
+#define BOOST_PERMUTATION_ITERATOR_HPP
+
+#include <iterator>
+
+#include <boost/iterator/iterator_adaptor.hpp>
+
+
+namespace boost
+{
+
+template< class ElementIterator
+        , class IndexIterator
+        , class ValueT        = use_default
+        , class CategoryT     = use_default
+        , class ReferenceT    = use_default
+        , class DifferenceT   = use_default >
+class permutation_iterator
+  : public iterator_adaptor< 
+             permutation_iterator<ElementIterator, IndexIterator, ValueT, CategoryT, ReferenceT, DifferenceT>
+           , ElementIterator, ValueT, CategoryT, ReferenceT, DifferenceT >
+{
+  typedef iterator_adaptor< 
+            permutation_iterator<ElementIterator, IndexIterator, ValueT, CategoryT, ReferenceT, DifferenceT>
+          , ElementIterator, ValueT, CategoryT, ReferenceT, DifferenceT > super_t;
+
+  friend class iterator_core_access;
+
+public:
+  permutation_iterator() : order_it_() {}
+
+  explicit permutation_iterator(ElementIterator x, IndexIterator y) 
+      : super_t(x), order_it_(y) {}
+
+  template<class OtherElementIterator, class OtherIndexIterator, class V, class C, class R, class D >
+  permutation_iterator(
+      permutation_iterator<OtherElementIterator, OtherIndexIterator, V, C, R, D> const& r
+      , typename enable_if_convertible<OtherElementIterator, ElementIterator>::type* = 0
+      , typename enable_if_convertible<OtherIndexIterator, IndexIterator>::type* = 0
+      )
+      : super_t(r.base())
+  {}
+
+private:
+    typename super_t::reference dereference() const
+        { return *(this->base() + *this->order_it_); }
+  
+    void increment() { ++this->order_it_; }
+    void decrement() { --this->order_it_; }
+
+    void advance(typename super_t::difference_type n)
+    {
+      std::advance( order_it_, n );
+    }
+
+    template<class OtherElementIterator, class OtherIndexIterator, class V, class C, class R, class D >
+    typename super_t::difference_type
+    distance_to( permutation_iterator<OtherElementIterator, OtherIndexIterator, V, C, R, D> const& y ) const
+    {
+      return std::distance( this->order_it_, y.order_it_ );
+    }
+
+    template<class OtherElementIterator, class OtherIndexIterator, class V, class C, class R, class D >
+    bool
+    equal( permutation_iterator<OtherElementIterator, OtherIndexIterator, V, C, R, D> const& y ) const
+    {
+      return( y.order_it_ == this->order_it_ );
+    }
+
+    IndexIterator order_it_;
+};
+
+
+template <class ElementIterator, class IndexIterator>
+permutation_iterator<ElementIterator, IndexIterator> 
+make_permutation_iterator( ElementIterator e, IndexIterator i )
+{
+    return permutation_iterator<ElementIterator, IndexIterator>( e, i );
+}
+
+
+} // namespace boost
+
+#endif