Returns true if this result does not compare equal to the other result. Comparison is done using operator!= on either value_type or error_type if the currently chosen state is the same for both results, otherwise true is returned.

Requires: operator!= must be a valid expression between value_type and A, and between error_type and B. If value_type is void, then so must be A; similarly for error_type and B.

Complexity: Whatever the underlying operator!= have. Constexpr and noexcept of underlying operations is propagated.

Guarantees: None.

Free function alias: There is a free function bool operator!=(const basic_result<A, B, C> &, const basic_outcome<A, B, C, D> &) which forwards perfectly to this function, by reversing the operands.