[fpc-pascal] User-defined operators and dummy parameters

Mark Morgan Lloyd markMLl.fpc-pascal at telemetry.co.uk
Mon Aug 12 16:03:34 CEST 2013

Sven Barth wrote:
> On 10.08.2013 12:04, Mark Morgan Lloyd wrote:
>> Is it possible to pass a dummy parameter to a user-defined operator,
>> with no expectation that it be referenced?
>> The following test program compiles OK but fails at runtime with an
>> error 217 on all platforms if the record is empty. It works if it
>> contains a variant, but not reliably with other types.
> It seems that the compiler does not detect here that the variants unit 
> is needed and thus does not impolitely add it. Please open a bug report 
> with your code as an example. As a workaround simply add the unit 
> "variants" to the unit where your operator is defined.


The reason I revisited this was after we were looking at apparent 
zero-size record problems elsewhere.

> Btw: You don't need the "s: Variant" for operators in mode Delphi or 
> mode ObjFPC as there you can use "Result" as usual (just write ": 
> Variant" as for normal functions).

Noted, my "eye was off the ball" while I was struggling with various 
errors in a test program somewhat larger than I've submitted (working up 
to 3-D arrays etc.).

Mark Morgan Lloyd
markMLl .AT. telemetry.co .DOT. uk

[Opinions above are the author's, not those of his employers or colleagues]

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