Perform a lexicographic three-way comparison of the specified lhs and the specified rhs strings by using CHAR_TRAITS::eq on each character; return the result of that comparison.
Declared in <bslstl_string.h>
template<
class CHAR_TYPE,
class CHAR_TRAITS,
class ALLOC1,
class ALLOC2>
bsl::String_ComparisonCategoryType<CHAR_TRAITS>
operator<=>(
bsl::basic_string<CHAR_TYPE, CHAR_TRAITS, ALLOC1> const& lhs,
std::basic_string<CHAR_TYPE, CHAR_TRAITS, ALLOC2> const& rhs) noexcept;