A == B or C

#include <cassert>

template <typename T>
struct proxy
{
        const T&        value;
        bool            previous;

        proxy(const T& value, bool previous) : value(value), previous(previous) {}

        operator bool ()
        {
                return previous;
        }

        proxy<T> operator or (const T& rhs)
        {
                return proxy<T>(value, previous or value == rhs);
        }
};


template <typename T>
proxy<T> operator == (const T& lhs, const T& rhs)
{
        return proxy<T>(lhs, lhs == rhs);
}

int             main()
{
        assert(5 != 6);
        assert(5 == 5);
        assert(5 == 5 or 6);
}