Operator overloading for enumerations

[apokroy 0]

Hello!

Is there any way to overload operators for enumerations?

I'm having fun trying to implement a Tri-State Boolean and Optional types, but I'm forced to use a record type for operators. Records look a bit ugly, have performance, RTTI and published properties issues ...

Now, my code looks like this:

TriBoolEnum = (Unknown, ExactFalse, ExactTrue);
TriBoolSet  = set of TriBoolEnum;

TriBool = record
private
  FValue: TriBoolEnum;
public
  class operator Initialize(out Value: TriBool);
  class operator Implicit(const Value: Boolean): TriBool; static; inline;
  class operator Implicit(const Value: TriBool): Boolean; static; inline;
  class operator Implicit(const Value: TriBool): TriBoolEnum; static; inline;
  class operator Implicit(const Value: TriBoolEnum): TriBool; static; inline;
  class operator Equal(const L, R: TriBool): TriBool; static; inline;
  class operator Equal(const L: Boolean; R: TriBool): TriBool; static; inline;
  class operator Equal(const L: TriBool; R: Boolean): TriBool; static; inline;
  class operator LogicalOr(const L, R: TriBool): TriBool; static; inline;
  class operator LogicalOr(const L: Boolean; R: TriBool): TriBool; static; inline;
  class operator LogicalOr(const L: TriBool; R: Boolean): TriBool; static; inline;
...

I want something like this:

TriBool = (Unknown, ExactFalse, ExactTrue);

TriBoolHelper = record helper for TriBool
class operator ...

It compiles, but overloading doesn't work.

 

Thanks in advance.