Greg: > Only casts to variable length unpacked arrays are impacted. That is my understanding too. > incompatibility can be avoided by excluding them from you proposal But they were not part of the proposal, which addresses only the assignment compatibility of various array types. However, one could widen the proposal to forbid bit-stream casting to a variable-sized target. Its existing uses can always be replaced (with more flexibility) by streaming concatenation {>>{...}}. As I see it there are three possible outcomes here: 1) Previous decisions (Manti 1447, 1702) relaxing array assignment compatibility could be revoked. I really don't like this; those changes met some important user needs, and also fixed a number of internal contradictions in the 2005 LRM, so undoing them would be not only undesirable but also far from trivial. 2) Continue with approximately the current suggestion for 2380, and accept that the semantics of bit-stream casting to queues and dynamic arrays will be incompatible between 2005 and 2009. 3) Make it illegal to do a bit-stream cast to a variable-length array, and expect users to change existing code to use streaming concatenation or some other substitute. I am willing to act as scribe for either (2) or (3), but I'm not qualified to decide which option is preferred. There's also option (0), do nothing and leave the present internal contradictions about array assignment compatibility, but I sincerely hope that would be vetoed by some balloting entity! -- Jonathan Bromley Consultant Doulos - Developing Design Know-how VHDL * Verilog * SystemVerilog * SystemC * PSL * Perl * Tcl/Tk * Project Services Doulos Ltd. Church Hatch, 22 Market Place, Ringwood, Hampshire, BH24 1AW, UK Tel: + 44 (0)1425 471223 Email: jonathan.bromley@doulos.com Fax: +44 (0)1425 471573 http://www.doulos.com -------------------------------------------------------------------------------- Doulos Ltd is registered in England and Wales with company no. 3723454 Its registered office is 4 Brackley Close, Bournemouth International Airport, Christchurch, BH23 6SE, UK. This message may contain personal views which are not the views of Doulos, unless specifically stated. -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.Received on Fri May 22 02:02:04 2009
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