(1) explicit unordered_map( size_type bucket_count = /*implementation-defined*/,
const Hash& hash = Hash(),
const KeyEqual& equal = KeyEqual(),
const Allocator& alloc = Allocator() ); (since C++11) (until C++14) unordered_map() : unordered_map( size_type(/*implementation-defined*/) {}
explicit unordered_map( size_type bucket_count,
const Hash& hash = Hash(),