%Warning-CASTCONST: t/t_castdyn_castconst_bad.v:20:11: $cast will always return one as 'int' is always castable from 'logic[31:0]' : ... In instance t : ... Suggest static cast 20 | i = $cast(v, 1); | ^~~~~ ... For warning description see https://verilator.org/warn/CASTCONST?v=latest ... Use "/* verilator lint_off CASTCONST */" and lint_on around source to disable this message. %Warning-CASTCONST: t/t_castdyn_castconst_bad.v:21:11: $cast will always return one as 'CLASSREFDTYPE 'Base'' is always castable from 'CLASSREFDTYPE 'Base'' : ... In instance t : ... Suggest static cast 21 | i = $cast(b, b); | ^~~~~ %Warning-CASTCONST: t/t_castdyn_castconst_bad.v:22:11: $cast will always return zero as 'CLASSREFDTYPE 'Base'' is not castable from 'CLASSREFDTYPE 'Other'' : ... In instance t 22 | i = $cast(b, o); | ^~~~~ %Error: Exiting due to