How to initialize constant array of generic record in Delphi

Question

In Delphi I can initialize a constant array of non generic record like this:

type
  TMapEntry = record
    Key: Integer;
    Value: Integer;
  end;

const
  Arr: array[0..0] of TMapEntry = ((Key: 1; Value: 10));

But when I try to extent the code in a more generic way then I can't initialize the constant array:

type
  TMapEntry<KeyType, ValueType> = record
    Key: KeyType;
    Value: ValueType;
  end;

const
  Arr: array[0..0] of TMapEntry<Integer, Integer> = ((Key: 1; Value: 10)); //<-- Compile error

I even tried to use a type alias but got the same compile error:

type
  TIntMapEntry = TMapEntry<Integer, Integer>; 

const
  Arr: array[0..0] of TIntMapEntry = ((Key: 1; Value: 10)); //<-- Compile error

Is there any way to initialize a constant array of generic record?

PS: I am using Delphi 10.3

David Heffernan · Accepted Answer · 2020-06-26 08:54:14Z

1

Is there any way to initialize a constant array of generic record?

No. Unfortunately this is a limitation of the compiler.

answered Jun 26, 2020 at 8:54

David Heffernan

616k46 gold badges1.1k silver badges1.5k bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Delmo Over a year ago

Thanks @David, if you claim that and didn't come up with a workaround it means there is no way so I accepted your answer as the correct one. But I'm curious: would not be easy for the compiler to solve this limitation? Could this be reported as a possible compiler improvement for future versions?

David Heffernan Over a year ago

@Delmo I don't know the internals of the compiler. It's worth submitting a QP report, if there is not already one in existence. Then at least there is a record.

Didier Cabalé Over a year ago

Just to state that "constant of generic record", like const cPair: TPair<byte, byte> = (Key: 1; Value: 1); is supported

Collectives™ on Stack Overflow

How to initialize constant array of generic record in Delphi

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related