-- Created on: 1993-01-07
-- Created by: Remi LEQUETTE
-- Copyright (c) 1993-1999 Matra Datavision
-- Copyright (c) 1999-2012 OPEN CASCADE SAS
--
-- The content of this file is subject to the Open CASCADE Technology Public
-- License Version 6.5 (the "License"). You may not use the content of this file
-- except in compliance with the License. Please obtain a copy of the License
-- at http://www.opencascade.org and read it completely before using this file.
--
-- The Initial Developer of the Original Code is Open CASCADE S.A.S., having its
-- main offices at: 1, place des Freres Montgolfier, 78280 Guyancourt, France.
--
-- The Original Code and all software distributed under the License is
-- distributed on an "AS IS" basis, without warranty of any kind, and the
-- Initial Developer hereby disclaims all such warranties, including without
-- limitation, any warranties of merchantability, fitness for a particular
-- purpose or non-infringement. Please see the License for the specific terms
-- and conditions governing the rights and limitations under the License.



generic class MapHasher from TCollection (Key as any)

	---Purpose: A hasher on the keys of a map instantiated from the
    	-- Collections component.
    	-- A hasher provides two functions:
    	-- -   The hashing function (HashCode) transforms a key
    	--   into a bucket index in the map. The number of values
    	--   that can be computed by the hashing function is equal
    	--   to the number of buckets in the map.
    	-- -   IsEqual is the equality test between two keys.
    	--   Hashers are used as parameters in generic maps
    	-- provided by the Collections component.
    	-- MapHasher is a generic class which depends on the type
    	-- of keys, provided that Key is a type from the Standard
    	-- package. In such cases MapHasher may be directly
    	-- instantiated with Key. Note that the package TColStd
    	-- provides some of these instantiations.
    	-- But if Key is not a type from the Standard package you
    	-- must consider MapHasher as a template and build a class
    	-- which includes its functions, in order to use it as a hasher
    	-- in a map instantiated from the Collections component.
    	-- Note that TCollection_AsciiString and
    	-- TCollection_ExtendedString classes correspond to
    	-- these specifications, in consequence they may be used as
    	-- hashers: when Key is one of these two types you may just
    	-- define the hasher as the same type at the time of
    	-- instantiation of your map.

is
    HashCode(myclass; K : Key; Upper : Integer) returns Integer;
	---Level: Public
	---Purpose: Returns a HasCode value  for  the  Key <K>  in the
	-- range 0..Upper.
	-- Default ::HashCode(K,Upper)
	
    IsEqual(myclass; K1, K2 : Key) returns Boolean;
	---Level: Public
	---Purpose: Returns True  when the two  keys are the same. Two
	-- same  keys  must   have  the  same  hashcode,  the
	-- contrary is not necessary.
	-- Default K1 == K2
	
end MapHasher;