[fpc-pascal] Can class function used in specialized class use intristic functions Low, High with generic type ?
lacak at zoznam.sk
Fri Apr 21 14:23:59 CEST 2017
> > I have some generic class:
> > generic T2DNumericArray<T> = object(specialize T2DArray<T>)
> > public
> > class function Truncate(Value: double): T; inline;
> > ...
> > In class function Truncate I want check if supplied Value is in
> range of T.
> > T will be always ordinal type (byte, integer) ... (I know this, but
> compiler does not of course)
> > Can I use in :
> > class function T2DNumericArray.Truncate(Value: double): T;
> > begin
> > if Value > High(T) then
> > Result := High(T)
> > else if Value < Low(T) then
> > Result := Low(T)
> > else
> > Result := Value;
> > end;
> > I understand, that from compiler POV T can be any type, so High()
> and Low() can be invalid, but I wonder if there is any way how to
> solve this.
> The compiler will use dummy values while parsing the generic, but
> during specialization it will use the correct ones. Though it might be
> that you'd need 3.1.1 for it (dont know right now when I had fixed that).
Yes, I can confirm, that in 3.1.1 it works, in 3.0.2 does not.
Thank you Sven
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