Perform a three-way comparison of the specified lhs and the specified rhs objects by using the comparison operators of t_LHS and t_RHS; return the result of that comparison. This function can be called in constant expressions only if t_LHS is not allocator-aware.
Declared in <bslstl_optional.h>
template<
class t_LHS,
class t_RHS>
requires (!BloombergLP::bslstl::Optional_DerivedFromOptional<t_RHS>) &&
three_way_comparable_with<t_LHS, t_RHS>
constexpr
compare_three_way_result_t<t_LHS, t_RHS>
operator<=>(
bsl::optional<t_LHS> const& lhs,
t_RHS const& rhs);