Implementations of language featuers

[Walt Karas]

Is there a reference (besides the ARM and hopefully consisting of WWW page(s) ) that outlines possible implementations (that is, generated object code) of C++ features? Something to point an experience C programmer to in response to comments like "I think calling a virtual function must involve a hash table lookup" or "I don't see how exception handling could not have execution time overhead even when no exceptions are thrown".