🚀 go-pugleaf

In article <C08p03.Htv@ucunix.san.uc.edu> you write:
> Hi folks,
> 
> Is there any options in the vhdl language that lets me declare types
> equivalent to the "union" in C. The brute force method that I can think of
> is to declare a record with all the possible choices in the original union
> as a strictly present field; and have integer tags to access the types: 
> 
> 	e.g.	-- pseudo vhdl code;
> 
> 	type union is record
> 		-- the tag to determine what field to use;
> 		access_type : integer;
> 		-- this is where the union starts
> 		-- list is declared earlier as an access type to a list;
> 		u1 : real;
> 		u2 : integer;
> 		u3 : list
> 		end record;
> 
> Is there any alternative to this lengthy  way of designing a data structure.
> 
> 
> thanks for any replies and comments.

Use one field of a type large enough to store each member of the union, and use
type conversion functions depending on the tag value. This is ineffecient in speed
but more efficient in storage (particularly for signals) - some type conversions
will be difficult too.

Kev.
-- 
Kevin Cameron          CLSI, Suite 100, 5457 Twin Knolls Rd., MD 21045, USA
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