Deduce the template parameter KEY from the value_type of the initializer_list supplied to the constructor of unordered_set. Deduce the template parameters HASH and ALLOCATOR from the other parameters passed to the constructor. This deduction guide does not participate unless the supplied HASH is invocable with a KEY, and the supplied allocator meets the requirements of a standard allocator.
Declared in <bslstl_unorderedset.h>
template<
class KEY,
class HASH,
class ALLOCATOR>
requires std::is_invocable_v<HASH, const KEY &> && bsl::IsStdAllocator_v<ALLOCATOR>
unordered_set<KEY, HASH, bsl::equal_to<KEY>, ALLOCATOR>(
std::initializer_list<KEY>,
bsl::allocator_traits<ALLOCATOR>::size_type,
HASH,
ALLOCATOR) -> unordered_set<KEY, HASH, bsl::equal_to<KEY>, ALLOCATOR>;