Re: Variant Record Defaults

[pa.dec.com!nntpd2.cxo.dec.com!bonmot!wallace@decuac.dec.com (Richard Wal]

BERRYMAN@orca.drep.dnd.ca (DON BERRYMAN) writes:
: 
: Please concider the following code fragment:
: 
:      package dstring is
:          type text (maxlen: positive := 64) is private;
:          ---STUFF DELETED--
:      private
:          type text (maxlen: positive := 64) is
:      	record
:      	    last: natural := 0;
:      	    data: string (1..maxlen);
:      	end record;
:      end dstring;
: 
:      with dstring;
:      procedure useit is
:         type buffer is record
:              data: dstring.text;
:         end record;
:         aaa: buffer;
:         bbb: dstring.text;
:      begin
:         null;
:      end useit;
: 
: 
: When compiled on VAX/VMS Ada I get the following:
: 
:      S2$ ada useit
:          3      type buffer is record
:      ...........1
:      %ADAC-I-CONS_OR_NUM_ERR, (1) CONSTRAINT_ERROR or NUMERIC_ERROR will be r
aised
:              here [LRM 11.1(5-6), F.9.5]
:              during evaluation related to record type buffer at line 3
:      %ADAC-I-ENDDIAGS, Ada compilation completed with 1 diagnostic
:      S2$
: 
: What appears to be the problem is that BUFFER.DATA is not using the default
: for MAXLEN. When I specify it in the record definition the message goes
: away. Since I can create the variable, BBB, of type DSTRING.TEXT it does not
: seem to be a problem with my definitions. So why does ADA not use the 
: default for BUFFER.DATA???  
: 
: I'm sure the reason is given in an obscure section of the LRM,
: 
: 
: Don Berryman
: Defence Research Establishment Pacific
: Canadian Forces Base Esquimalt
: Victoria, BC, CANADA, V0S-1B0
: 604-363-2731    604-363-2856fax
: berryman@orca.drep.dnd.ca
: 
: