Virtual inline in C++

[Jacek]

Is it possible to declare a virtual inline in C++? Does this poses a problem to the compilation and/or performance when the call for a virtual inline function is from a secondary purpose?

[Ashok.M]

Is it possible to declare a virtual inline in C++?

Yes

Does this poses a problem to the compilation and/or performance when the call for a virtual inline function is from a secondary purpose?

No, it does not poses any problem.

[Jacek]

What surprises me is that I thought during the compilation, the compiler does not know whether it is the type of object that calls the declared virtual (ie: depending on the parent class or function Class) and thus may not be able to inline code. Am I wrong?

[Ashok.M]

No. It is quite rightly. But nothing prevents you declare virtual inline and nothing prevents a compiler to inline a call to a virtual function if he knows to resolve statically.

[Jacek]

Here is what I could have a sample code, which highlights the call for a virtual inline from a subclass that the compiler knows to solve statically:

class A
{
virtual inline f() {...} 
}; 
class B: public A 
{
virtual inline f() {...} 
}; 
main () 
{
A * a; 
a = new B(); 
a -> f(); 
}

In this case the compiler can not inline a-> f () a priori as I understand it, but in which case it may do as you pointed out to me?

[Ashok.M]

In a static:

virtual void B::f() { A::f(); }
// Or
B b;
b.f();