This error message is issued if you try to apply the standard function TypeOf to an object type that does not have a virtual method table.
A simple workaround is to declare a dummy virtual procedure to force the compiler to generate a VMT.
program Produce; type TMyObject = object procedure MyProc; end; procedure TMyObject.MyProc; begin (*...*) end; var P: Pointer; begin P := TypeOf(TMyObject); (*<-- Error message here*) end.
The example tries to apply the TypeOf standard function to type TMyObject which does not have virtual functions, and therefore no virtual function table (VMT).
program Solve; type TMyObject = object procedure MyProc; procedure Dummy; virtual; end; procedure TMyObject.MyProc; begin (*...*) end; procedure TMyObject.Dummy; begin end; var P: Pointer; begin P := TypeOf(TMyObject); end.
The solution is to introduce a dummy virtual function, or to eliminate the call to TypeOf.
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