Re: set a pointer to const

[Hans Boldt <boldt@xxxxxxxxxx>]

Steve Richter wrote:
> When a procedure argument is const, a pointer cannot be set to the argument.
> Is it possible to declare a pointer as const in order for the pointer to be
> set?
>
> here is an example:
>
>   ** declare a ds called "Address"
>   d Address         ds                  qualified
>   d  Street                       30a   varying
>   d  City                         30a   varying
>   d  State                         2a
>   d  Zip                          10a
>
>   ** proc to print the address
>   pPrintAddress     b
>   dPrintAddress     pi
>   d InAddress                           const likeds(Address)
>
>   d pStreet         s               *
>    /free
>       pStreet = %addr(InAddress.Street) ;
>       RplUnprintableChars( pStreet: %size(InAddress.Street)) ;
>    /end-free
>   p                 e
>
> the pointer pStreet cannot be set to InAddress because InAddress is const.
>
> thanks,
No, you can't do that.  By declaring a parameter as CONST, you
indicate to RPG that you do not intend to modify the parameter.
Setting a pointer to the address of the parameter would allow you to
change the value of the parameter via a based variable, which
violates your promise not to.

If you do really want to change the value of the parameter, then
define the parameter as a normal reference parameter.

Alternatively, copy the value you're interested in to a local
variable, and do whatever you want with that.

Cheers!  Hans