SystemVerilog - virtual class implementing interface - compilation error when interface functions not at least redeclared in virtual class - why?

SystemVerilog
,
4

In reply to dave_59:

Hi Dave,

Cadence got back to me and it seems like the error is correct. According to the LRM in 8.26.7:

It shall be illegal to use an interface class to partially define a virtual class without fulfilling the interface class prototype requirements. In other words, when an interface class is implemented by a virtual class, the virtual class must do one of the following for each interface class method prototype:
— Provide a method implementation
— Re-declare the method prototype with the pure qualifier

Any reason the LRM mandates this?