OffsetOf Delphi ekvivalent?

[himitsu]

Code:

#define offsetof(struct_type, member) \
          (size_t) &(((struct_type *)0)->member)

This would presumably it look something like this in Delphi.

Delphi-Quellcode:

function OffsetOf(StructType: Type; Member: string): Integer;
  type P = ^StructType;

  begin
    //Result := Integer(@P(nil)^.[Member]) - Integer(@P(nil)^);
    //Result := Integer(@P(nil)^.[Member]) - Integer(P(nil));
    //Result := Integer(@P(nil)^.[Member]) - 0;
    Result := Integer(@P(nil)^.[Member]);
  end;

My code would look something like this.

Delphi-Quellcode:

function OffsetOf(StructType: Type; Member: string): Integer;
  var X: StructType;

  begin
    Result := Integer(@X.[Member]) - Integer(@X);
  end;

But Delphi does not support macros.

Zitat von nanix:

Code:

length = OffsetOf(member, CharData) +  sizeof(member->CharData);

length := Integer(@PMember(nil).CharData) + SizeOf(TMember.CharData);