This component‐private metafunction derives from bsl::true_type if (template parameter) t_TYPE occurs exactly once as an alternative of (template parameter) t_VARIANT, and bsl::false_type otherwise, where two types that differ only in top‐level cv‐qualification are considered to be the same. The primary template (used when t_VARIANT is not a bsl::variant) is not defined.
Synopsis
Declared in <bslstl_variant.h>
template<
class t_TYPE,
class t_VARIANT>
struct Variant_HasUniqueCVType;