[fpc-pascal] C Enum vs. Integer

Jonas Maebe jonas.maebe at elis.ugent.be
Thu Sep 13 15:45:33 CEST 2012

Guillermo Martínez Jiménez wrote on Thu, 13 Sep 2012:

>> On 12 Sep 2012, at 19:11, Johann Glaser wrote:
>>> Can I translate this 1:1, i.e., define an Enum in Pascal and just ignore
>>> the compiler warnings about reused values?
>>> Or should I rather define all these types as Integer and define
>>> constants for all values?
>> It depends on whether you need arithmetic or not. If you do, use  
>> integer constants, otherwise you can use an enum.
> Actually you cannot.  FPC optimizes enumerations in some cases (i.e.
> in Delphi mode) but GCC uses 32bit for enumerations alwais.

The size of an enum in gcc depends on whether or not the -fshort-enums  
command line option is used, and on the number of bits required to  
represent its upper bound value.

> Anyway you can still use enums, but telling to FPC that you want to
> set its size by directives $PACKENUM and $ENUMSIZE.

It's $PACKENUM *or* $ENUMSIZE (they affect the same compiler setting)

Anwyay, yes, that's also what I said the part of my original mail that  
you cut away.


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