Re: Explanation of a datastructure as a parameter...

Jon, isn't this what "VALUE" means?

I have long advocated that RPG should have const-and-I-mean-it whereby a copy is _always_ made. Then const would mean what most people already think it means!

On 6/16/12 9:22 AM, Jon Paris wrote:

On 2012-06-15, at 7:36 PM, rpg400-l-request@xxxxxxxxxxxx wrote:

What exactly scenario can you change the contents of a parameter that uses Const? If there's a scenario, open a PMR.

Const means different things in the caller and the callee.

In the caller it means make a copy if the datatype/size does not exactly match.

In the callee it means read-only.

As a result regardless of what the caller codes, if the callee does not code const, the values can be changed. Whether the caller "sees" those changes or not depends on whether a copy was made. Since RPG III, CL, and COBOL have no proto capability then coding const in the caller really offers no protection. But a lot of people mistakenly think that by coding const that they are safe from any and all callee changes.

I have long advocated that RPG should have const-and-I-mean-it whereby a copy is _always_ made. Then const would mean what most people already think it means!


Jon Paris

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