Enum declaration with subrange bounds violation?
type
{$MINENUMSIZE 2}
TMyEnum2 = (
Enum11 = 1,
Enum12 = 2,
Enum13 = 3,
Enum1Mid1 = $7fff, // No warning
Enum1Mid2 = $8000, // No warning
Enum1Max = $ffff); // No warning
{$MINENUMSIZE 4}
TMyEnum4 = (
Enum21 = 1,
Enum22 = 2,
Enum23 = 3,
Enum2Mid1 = $7fffffff, // No warning
Enum2Mid2 = $80000000, // Warning
Enum2Max = $ffffffff); // Warning
The two last entries in the second type declaration above, gives a warning: W1012 Constant expression violates subrange bounds.
Any known QC issue or workaround for this?
Any reason that the enum can’t use the most signficant bit in a 4 byte size enum?
MaxInt ($7FFFFFFF) seems to be the limit, I’m guessing that the compiler uses Longint (ie. signed dword) for 4-byte enums. Funny that this gets rid of the warning (in XE2):
type
TMyEnum4 = (
Enum21 = 1,
Enum22 = 2,
Enum23 = 3,
Enum2Mid1 = MaxInt, // No warning
Enum2Mid2 = MaxInt + 1, // No Warning
Enum2Max = MaxInt + MaxInt + 1); // No Warning
However, although Ord(Enum2Max) returns $FFFFFFFF as expected, High(TMyEnum4) still returns $7FFFFFFF.
That workaround would need a Assert(SizeOf(MaxInt) = 4) somewhere 🙂