SystemVerilog OOP Mastery · All levels
No Multiple Inheritance (Only Interface-Class Contracts): Concept Explained
Concept Explained for No Multiple Inheritance (Only Interface-Class Contracts).
Concept
In short: C++ can inherit implementation from multiple bases; SystemVerilog cannot. In DV, you combine one extends chain with interface-class contracts and composition helpers.
C++ supports multiple inheritance of implementation, so a derived class can reuse code and data members from more than one concrete base class. That model enables rich mixins but can introduce ambiguity (diamond patterns) and complex method-resolution rules.
SystemVerilog classes extend exactly one base class. You can still implement multiple interface classes, but those interfaces contain signatures only. Practical architecture therefore uses a single behavioral base (often a UVM base class), plus helper objects that own reusable behavior, plus interface-class contracts that document required APIs.
The idiom is: extends for identity and lifecycle, implements for capability contracts, composition for reusable behavior.