If I try to compile your unit, it fails but the error is not the same. The first message lines are:
unit1.pas(13,16) Error: Forward declaration not solved "procedure str:AnsiString;"
unit1.pas(14,22) Error: Forward declaration not solved "operator :=(const Double):<record type>;"
unit1.pas(15,22) Error: Forward declaration not solved "operator :=(const LongInt):<record type>;"
unit1.pas(16,22) Error: Forward declaration not solved "operator :=(const Int64):<record type>;"
unit1.pas(17,22) Error: Forward declaration not solved "operator +(const Tcomplex;const Tcomplex):<record type>;"
unit1.pas(18,22) Error: Forward declaration not solved "operator -(const Tcomplex;const Tcomplex):<record type>;"
...
I am using Lazarus 1.1 Revision 37429, FPC 2.7.1