[fpc-pascal] Question about functions returning a string

Ewald ewald at yellowcouch.org
Mon Dec 1 16:10:20 CET 2014

On 12/01/2014 04:34 AM, leledumbo wrote:
>> So in general, one should not use managed types in the prototype of an 
>> exported (public) function?
> Bingo. At least not until we have properly sharable RTL.

The problem lies not with a sharable RTL. As mentioned, I do not want to
/use/ these managed types in another language. I just want to pass them
along :-)

>> my thought was that it would be 
>> possible to pass along these managed types (especially string, as it is 
>> a pointer internally) to another pascal function (a callback in my case).
> You can still pass pointer to its first element as a PChar, treating it
> read-only in the caller for safety reason (though it's possible to make it
> writable as well, but the safety burden is propagated to the caller).

Actually I was trying to avoid PChar's ;-)

In the meanwhile, I've fixed my issue by not returning a string as a
result, but as an out parameter:

Function Bla: String;

... becomes ...

Procedure Bla(out Result: String);

This seems to work. How portable it is, I do not know, I guess time will
be the judge and jury on that.

Anyway, thanks to you all!


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