Return true if the specified lhs and rhs optional objects do not have the same value, and false otherwise. Two optional objects do not have the same value if one is disengaged and the other is engaged, or if both are engaged and the values of their underlying objects do not compare equal. This function can be called in constant expressions only if neither t_LHS_TYPE nor t_RHS_TYPE is allocator-aware.
Declared in <bslstl_optional.h>
template<
class t_LHS_TYPE,
class t_RHS_TYPE>
constexpr
bool
operator!=(
bsl::optional<t_LHS_TYPE> const& lhs,
bsl::optional<t_RHS_TYPE> const& rhs);