Question

This is more a curiosity than anything else…

Suppose I have a C++ class Kitty as follows:

class Kitty
{
    void Meow()
    {
        //Do stuff
    }
}

Does the compiler place the code for Meow() in every instance of Kitty?

Obviously repeating the same code everywhere requires more memory. But on the other hand, branching to a relative location in nearby memory requires fewer assembly instructions than branching to an absolute location in memory on modern processors, so this is potentially faster.

I suppose this is an implementation detail, so different compilers may perform differently.

Keep in mind, I’m not considering static or virtual methods here.

Answer 1

I believe the standard way for instance methods is to be implemented like any static method, only once, but having the this pointer passed on a specific register or on the stack to perform the call.