Override identifier after destructor in C++11

Yes. If the base destructor is not virtual then the override marking will cause the program to not compile:

class Base
{
public:
    ~Base()
    {}
};

class Derived : public Base
{
public:
    virtual ~Derived() override //error: '~Derived' marked 'override' but does
                                //        not override any member functions
    {}
};