Re: parameter passing pitfall

Just curious --

Why doesn't the compiler check that the arguments are
the correct length, not just the correct type?

Phil

--- Joel Fritz <JFritz@sharperimage.com> wrote:
> Here's a little something I probably should have
> realized about passing by
> reference, but had to learn the hard way.  I was
> debugging a program a
> couple of days ago found out that the problem was
> having procedure
> parameters out of order.  The parameters were
> defined as read only reference
> (const) and I was accidentally stuffing a 25
> character field into a two
> character field.  It worked just fine except that
> the file update resulted
> in some odd data.
>
> Here's a sample prototype for a procedure that
> concatenates the two fields
> in the order they're specified in the prototype
> without trimming any blanks:
>
> D combine         PR            22A
> D twochar                        2A   CONST
> D twentychar                    20A   CONST
>
> If you call it with a twenty character field
> followed by a two character
> field, the result will be the first two characters
> of the twenty character
> field followed by the contents of the second field
> followed by 18 blanks.
> If you pass a two character field followed by a
> twenty character field,
> you'll get what you expect.
>
> I guess the moral of the story is to get your
> argument list right the first
> time, although you might argue that converting the
> larger string to a
> smaller one is a type cast that results in a loss of
> precision.  Forewarned
> is forearmed. <g>
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