Method invoke

tutorials/external/catch.hpp:4293–4301

        OcMethod( Class cls, SEL sel ) : m_cls( cls ), m_sel( sel ) {}

        virtual void invoke() const {
            id obj = [[m_cls alloc] init];

            performOptionalSelector( obj, @selector(setUp)  );
            performOptionalSelector( obj, m_sel );
            performOptionalSelector( obj, @selector(tearDown)  );

            arcSafeRelease( obj );
        }
    private:
        virtual ~OcMethod() {}