ID:	  N-007

Proposed by:  David Bishop and Paul Menchini  12/02
Analyzed by:  
Resolved:     

Summary:
    Create a function named IEEE.numeric_std.match
    and make it based on the IEEE.std_logic_1164.match.
    Rewrite IEEE.numeric_std.std_match to be an alias to
    the corresponding match function.

Detail:
    IEEE.numeric_std.std_match includes overloading for 
    std_logic_vector.  This functionality should be available 
    to any user of std_logic_1164.  It was desired to move
    std_match for std_logic_vector to std_logic_1164, however,
    that would break references of the form IEEE.numeric_std.std_match.

    Hence, in a coordinated effort with std_logic_1164, match was
    added to std_logic_1164 for std_logic family types and match
    was added to numeric_std and numeric_bit for unsigned and signed
    types.   

    Rather than maintain the functionality of std_match, std_match
    will be an alias to the match function.  

    This proposal suggests three modifications:
      
Add match to std_logic_1164 for std_logic_1164 types.
    See std_logic_1164 CP-010

	
Add match as follows to numeric_std:

	    function match (L, R: signed) return boolean is
	    begin
	      return ieee.std_logic_1164.match(
			std_logic_vector(L),
			std_logic_vector(R));
	    end function std_match;

	    function match (L, R: unsigned) return boolean is
	    begin
	      return ieee.std_logic_1164.match(
			std_logic_vector(L),
			std_logic_vector(R));
	    end function std_match;

	
Remove the std_match functions from numeric_std and numeric_bit

	    alias std_match is
		  ieee.std_logic_1164.match [
				 ieee.std_logic_1164.std_ulogic,
				 ieee.std_logic_1164.std_ulogic
			] return std.standard.boolean;
	    alias std_match is
		  ieee.std_logic_1164.match [
				 ieee.std_logic_1164.std_ulogic_vector,
				 ieee.std_logic_1164.std_ulogic_vector,
		        ] return std.standard.boolean;
	    alias std_match is
		  ieee.std_logic_1164.match [
				 ieee.std_logic_1164.std_logic_vector,
				 ieee.std_logic_1164.std_logic_vector,
		        ] return std.standard.boolean;
	    alias std_match is
		  match [
				 unsigned,
				 unsigned
			] return std.standard.boolean;
	    alias std_match is
		  match [
				 signed,
				 signed
			] return std.standard.boolean;



Analysis:
	[To be performed by the Working Group.]

Resolution:
	[To be determined by the Working Group.]


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Please send feedback to David Bishop
dbishop@vhdl.org