Re: CONST vs. VALUE

[Jon.Paris@xxxxxx]

 >> What's the difference between using CONST and VALUE on ILE parm lists?

Huge difference.  The RPG Redbook goes into it in more detail but here's
the short version.

CONST is a pass by reference i.e. a pointer is passed just as it would be
if there was no keyword.  The thing that CONST buys you is that if there is
a minor difference in the parm being passed and the proto definition the
compiler takes care of it.  e.g. Proto says 15P 5 parm is 10S 2 - in this
case the compiler generates a 15P 5 temporary field - moves the parm to it,
and passes the temp to the called program/procedure.

VALUE actually passes the _content_ of the field on the stack (not a
pointer).  It deals with differences just as CONST does but it is _always_
a copy of the data that is passed whereas CONST may pass a pointer to the
original field or to a temp.

CONST can be used for both program and procedure calls - VALUE can only be
used when calling procedures (i.e. bound calls)



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