include/adt/slice.h

#pragma once

template<typename Container>
struct slice_view
{
  typedef Container                                             container_type;

  typedef typename container_type::const_iterator               const_iterator;
  typedef typename container_type::iterator                     iterator;

  typedef typename container_type::const_reverse_iterator       const_reverse_iterator;
  typedef typename container_type::reverse_iterator             reverse_iterator;

  slice_view (Container const &container, size_t offset)
    : container (container)
    , offset (offset)
  {
    if (container.size () < offset)
      throw std::logic_error ("slice out of bounds");
    else if (container.size () == offset)
      throw std::logic_error ("empty slice interval");
  }

  const_iterator begin () const { return container.begin () + offset; }
  const_iterator end   () const { return container.end   ();          }

  const_reverse_iterator rbegin () const { return container.rbegin () + offset; }
  const_reverse_iterator rend   () const { return container.rend   ();          }

private:
  container_type const &container;
  size_t offset;
};

template<typename Container>
slice_view<Container>
slice (Container const &container, size_t offset)
{
  return slice_view<Container> (container, offset);
}
Revision:	1.3
Committed:	Mon Feb 7 19:18:44 2011 UTC (15 years, 8 months ago) by sf-pippijn
Content type:	text/plain
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.2:	+2 -2 lines
Log Message:	inventory_widget: don't fault on pgdn with only one item by Jonathan Neuschäfer <j.neuschaefer@gmx.net>
#	User	Rev	Content
1	sf-pippijn	1.1	#pragma once
2
3			template<typename Container>
4	sf-pippijn	1.2	struct slice_view
5	sf-pippijn	1.1	{
6	sf-pippijn	1.2	typedef Container container_type;
7	sf-pippijn	1.1
8	sf-pippijn	1.2	typedef typename container_type::const_iterator const_iterator;
9			typedef typename container_type::iterator iterator;
10	sf-pippijn	1.1
11	sf-pippijn	1.2	typedef typename container_type::const_reverse_iterator const_reverse_iterator;
12			typedef typename container_type::reverse_iterator reverse_iterator;
13
14			slice_view (Container const &container, size_t offset)
15	sf-pippijn	1.1	: container (container)
16			, offset (offset)
17			{
18			if (container.size () < offset)
19	sf-pippijn	1.3	throw std::logic_error ("slice out of bounds");
20	sf-pippijn	1.1	else if (container.size () == offset)
21	sf-pippijn	1.3	throw std::logic_error ("empty slice interval");
22	sf-pippijn	1.1	}
23
24			const_iterator begin () const { return container.begin () + offset; }
25			const_iterator end () const { return container.end (); }
26
27	sf-pippijn	1.2	const_reverse_iterator rbegin () const { return container.rbegin () + offset; }
28			const_reverse_iterator rend () const { return container.rend (); }
29
30	sf-pippijn	1.1	private:
31			container_type const &container;
32			size_t offset;
33			};
34
35			template<typename Container>
36	sf-pippijn	1.2	slice_view<Container>
37	sf-pippijn	1.1	slice (Container const &container, size_t offset)
38			{
39	sf-pippijn	1.2	return slice_view<Container> (container, offset);
40	sf-pippijn	1.1	}