imgtools/imglib/boostlibrary/boost/iterator/filter_iterator.hpp
changeset 2 39c28ec933dd
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/imgtools/imglib/boostlibrary/boost/iterator/filter_iterator.hpp	Mon May 10 19:54:49 2010 +0100
@@ -0,0 +1,135 @@
+// (C) Copyright David Abrahams 2002.
+// (C) Copyright Jeremy Siek    2002.
+// (C) Copyright Thomas Witt    2002.
+// Distributed under the Boost Software License, Version 1.0. (See
+// accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+#ifndef BOOST_FILTER_ITERATOR_23022003THW_HPP
+#define BOOST_FILTER_ITERATOR_23022003THW_HPP
+
+#include <boost/iterator.hpp>
+#include <boost/iterator/iterator_adaptor.hpp>
+#include <boost/iterator/iterator_categories.hpp>
+
+#include <boost/type_traits/is_class.hpp>
+#include <boost/static_assert.hpp>
+
+namespace boost
+{
+  template <class Predicate, class Iterator>
+  class filter_iterator;
+
+  namespace detail
+  {
+    template <class Predicate, class Iterator>
+    struct filter_iterator_base
+    {
+        typedef iterator_adaptor<
+            filter_iterator<Predicate, Iterator>
+          , Iterator
+          , use_default
+          , typename mpl::if_<
+                is_convertible<
+                    typename iterator_traversal<Iterator>::type
+                  , random_access_traversal_tag
+                >
+              , bidirectional_traversal_tag
+              , use_default
+            >::type
+        > type;
+    };
+  }
+  
+  template <class Predicate, class Iterator>
+  class filter_iterator
+    : public detail::filter_iterator_base<Predicate, Iterator>::type
+  {
+      typedef typename detail::filter_iterator_base<
+          Predicate, Iterator
+      >::type super_t;
+
+      friend class iterator_core_access;
+
+   public:
+      filter_iterator() { }
+
+      filter_iterator(Predicate f, Iterator x, Iterator end_ = Iterator())
+          : super_t(x), m_predicate(f), m_end(end_)
+      {
+          satisfy_predicate();
+      }
+
+      filter_iterator(Iterator x, Iterator end_ = Iterator())
+        : super_t(x), m_predicate(), m_end(end_)
+      {
+        // Pro8 is a little too aggressive about instantiating the
+        // body of this function.
+#if !BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
+          // Don't allow use of this constructor if Predicate is a
+          // function pointer type, since it will be 0.
+          BOOST_STATIC_ASSERT(is_class<Predicate>::value);
+#endif 
+          satisfy_predicate();
+      }
+
+      template<class OtherIterator>
+      filter_iterator(
+          filter_iterator<Predicate, OtherIterator> const& t
+          , typename enable_if_convertible<OtherIterator, Iterator>::type* = 0
+          )
+          : super_t(t.base()), m_predicate(t.predicate()), m_end(t.end()) {}
+
+      Predicate predicate() const { return m_predicate; }
+
+      Iterator end() const { return m_end; }
+
+   private:
+      void increment()
+      {
+          ++(this->base_reference());
+          satisfy_predicate();
+      }
+
+      void decrement()
+      {
+        while(!this->m_predicate(*--(this->base_reference()))){};
+      }
+
+      void satisfy_predicate()
+      {
+          while (this->base() != this->m_end && !this->m_predicate(*this->base()))
+              ++(this->base_reference());
+      }
+
+      // Probably should be the initial base class so it can be
+      // optimized away via EBO if it is an empty class.
+      Predicate m_predicate;
+      Iterator m_end;
+  };
+
+  template <class Predicate, class Iterator>
+  filter_iterator<Predicate,Iterator>
+  make_filter_iterator(Predicate f, Iterator x, Iterator end = Iterator())
+  {
+      return filter_iterator<Predicate,Iterator>(f,x,end);
+  }
+
+  template <class Predicate, class Iterator>
+  filter_iterator<Predicate,Iterator>
+  make_filter_iterator(
+      typename iterators::enable_if<
+          is_class<Predicate>
+        , Iterator
+      >::type x
+    , Iterator end = Iterator()
+#if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
+    , Predicate* = 0
+#endif 
+  )
+  {
+      return filter_iterator<Predicate,Iterator>(x,end);
+  }
+
+} // namespace boost
+
+#endif // BOOST_FILTER_ITERATOR_23022003THW_HPP