Calling scope resolution-ed CPP function from Objective C++ [duplicate]

I have a cpp function defined in a dynamic library like this

namespace A
{
namespace B
{
    class C
    {
     public:
        static funcA();
    };
}
}

Now I am calling the above function from obcpp.mm file in the following manner:

void sample()
{
    A::B::C::funcA();
}

This gives me error like Undefined Symbol A::B::C::funcA

Would highly appreciate any help regarding this.