On Sat, 13 Jul 2019, Ben Grasset wrote:
On Sat, Jul 13, 2019 at 2:37 PM Ondrej Pokorny <laza...@kluug.net> wrote:
I do exactly the same - check the low/high bounds in a type helper :)
Yes, and I am tired of typing it as well :)
You can pretty easily write a generic function that will work on pretty
much any enum for this, BTW:
program Example;
{$mode Delphi}
uses TypInfo, SysUtils;
function TryConvert<T>(const Value: SizeInt): T; inline;
begin
if (Value >= SizeInt(Low(T))) and (Value <= SizeInt(High(T))) then
Result := T(Value)
else
raise EConvertError.Create(
Format(
'Invalid value for %s : %d', [
PTypeInfo(TypeInfo(T))^.Name,
Value
]
)
);
For the record:
The above will not work in delphi for at least 2 reasons:
1. Simple fuctions are not supported. Can be worked around by making it part
of a record.
2. The Low(T) does not work, as there is no way to tell Delphi that T must
be an enum.
Michael.
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