On 13.04.2018 23:16, Sven Barth via fpc-devel wrote:
I wasn't talking about the boundaries. I meant undefined values inside
the enum. If we want such a cast operator to work with such enums as
well it should check for invalid values inside the enum, too.
Otherwise the operator isn't worth it and should be forbidden for such
enums.
How can I know what you mean with /"//What about enums with holes?//"/ ? :)
Nevertheless, as I already said in the reply to Martok, there are no
undefined values inside an enum with assigned values. The values only
don't have an alias. See the Delphi docs:
http://docwiki.embarcadero.com/RADStudio/Tokyo/en/Simple_Types_(Delphi)#Enumerated_Types_with_Explicitly_Assigned_Ordinality
/type Size = (Small = 5, Medium = 10, Large = Small + Medium);/
/An enumerated type is, in effect, a subrange whose lowest and highest
values correspond to the lowest and highest ordinalities of the
constants in the declaration. In the previous example, the Size type has
11 possible values whose ordinalities range from 5 to 15. (Hence the
type array[Size] of Char represents an array of 11 characters.) Only
three of these values have names, but the others are accessible through
typecasts and through routines such as Pred, Succ, Inc, and Dec.
/IMO the docs are very clear about it. BTW. the Delphi 7 docs have the
same information:
http://docs.embarcadero.com/products/rad_studio/cbuilder6/EN/CB6_ObjPascalLangGuide_EN.pdf
see page 5-7 and 5-8
Ondrej
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