program toperator9; // Check IN operator support {$mode objfpc}{$H+} {$apptype console} type TFoo = record F: Integer; end; operator in(const I: Integer; const Foo: TFoo): Boolean; begin Result := Foo.F = I; end; var Foo: TFoo; begin Foo.F := 1; if not (1 in Foo) then halt(1); if 2 in Foo then halt(2); WriteLn('ok'); end.