Vtable for virtual functions in D

[Henrik]

Does anyone know if D is using the vtable implementation for 
virtual functions just like most C++ compilers? If yes, can 
someone explain the advantages of this strategy? A function 
pointer in C is regarded as expensive because of missing 
inlining, but a double indirection through a vtable just looks 
insane - if there aren't really good reasons for such an 
implementation. Does it make class inheritance or class 
polymorphism much simpler to implement or what is the reason?

I have worked with C in embedded systems for many years now, and 
for our modern Linux systems we are using a combination of C and 
Java today. Java for parts where memory safety is more important 
than speed/determinism, and C for the critical real time parts. 
There should exist a language between these worlds, where we can 
achieve memory safety at relatively small costs. C++ is not 
really an alternative, and D looks much more pleasant for us C 
programmers than for example Rust.