Operator overloading and macros are trivial solutions to such a riddle.
And if so, can it actually be useful?
Well, with some imagination... One possible use case I can think of are unit tests or integration tests in which you want to make sure that your overloaded operator== for some class works correctly and you know for sure that it works incorrectly if it reports equality for different operands when it's not supposed to do that:
class A {public: A(int i); bool operator==(int i) const; // ...};A a(1);if ((a==1)&&(a==2)&&(a==3)) { // failed test // ...}