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delphidelphi-xe6

Overloading global functions in helpers

I'm adding some functions for TPoint and if I use the same name as the global function, I can't see it inside helper function. Am I missing something or I can't simply do that?

uses 
  Winapi.Windows, Math;

type
  TPointHelper = record helper for TPoint
    function InRange(const AMin, AMax: TPoint): Boolean;
  end;

implementation

function TPointHelper.InRange(const AMin, AMax: TPoint): Boolean;
begin
  Result := InRange(X, AMin.X, AMax.X) and InRange(Y, AMin.Y, AMax.Y);
end;

end.
Solution

  • You need to fully qualify the call to InRange because the compiler sees the InRange in the closest scope. Which is your helper method. Your code should read:

    function TPointHelper.InRange(const AMin, AMax: TPoint): Boolean;
begin
  Result := Math.InRange(X, AMin.X, AMax.X) and Math.InRange(Y, AMin.Y, AMax.Y);
end;