Even if you call a pure virtual function of an abstract base class, the compiler can devirtualize if it can determine the type anyway due to data flow analysis.

Even if you call a pure virtual function of an abstract base class, the compiler can devirtualize if it can determine the type anyway due to data flow analysis. There are limitations but with LTO you’d be surprised at how effective the compiler is here. Also in Rust you’re never going through the vtable unless it’s a &dyn Trait and the compiler fails to devirtualize.