indexing
	description: "[
		Strategies for computing several features of subsets. The computing
		strategy is optimized depending on the type of elements contained in
		the set.
	]"
	status: "See notice at end of class"
	date: "$Date$"
	revision: "$Revision$"

deferred class interface
	SUBSET_STRATEGY [G]

feature -- Comparison

	disjoint (set1, set2: TRAVERSABLE_SUBSET [G]): BOOLEAN
			-- Are set1 and set2 disjoint?
		require
			sets_exist: set1 /= void and set2 /= void
			same_rule: set1.object_comparison = set2.object_comparison

feature -- Basic operations

	symdif (set1, set2: TRAVERSABLE_SUBSET [G])
			-- Remove all items of set1 that are also in set2, and add all
			-- items of set2 not already present in set1.
		require
			sets_exist: set1 /= void and set2 /= void
			same_rule: set1.object_comparison = set2.object_comparison

invariant

		-- from ANY
	reflexive_equality: standard_is_equal (Current)
	reflexive_conformance: conforms_to (Current)

indexing
	library: "[
			EiffelBase: Library of reusable components for Eiffel.
	]"
	status: "[
			Copyright 1986-2001 Interactive Software Engineering (ISE).
			For ISE customers the original versions are an ISE product
			covered by the ISE Eiffel license and support agreements.
	]"
	license: "[
			EiffelBase may now be used by anyone as FREE SOFTWARE to
			develop any product, public-domain or commercial, without
			payment to ISE, under the terms of the ISE Free Eiffel Library
			License (IFELL) at http://eiffel.com/products/base/license.html.
	]"
	source: "[
			Interactive Software Engineering Inc.
			ISE Building
			360 Storke Road, Goleta, CA 93117 USA
			Telephone 805-685-1006, Fax 805-685-6869
			Electronic mail <info@eiffel.com>
			Customer support http://support.eiffel.com
	]"
	info: "[
			For latest info see award-winning pages: http://eiffel.com
	]"

end -- class SUBSET_STRATEGY