Proposed resolution:

Add the following two rows to table 93 (unordered associative container requirements) in section [unord.req]:

Unordered associative container requirements (in addition to container)

expression	return type	assertion/note pre/post-condition	complexity
b.cbegin(n)	const_local_iterator	n shall be in the range [0, bucket_count()). Note: [b.cbegin(n), b.cend(n)) is a valid range containing all of the elements in the nth bucket.	Constant
b.cend(n)	const_local_iterator	n shall be in the range [0, bucket_count()).	Constant

Add to the synopsis in [unord.map]:

const_local_iterator cbegin(size_type n) const;
const_local_iterator cend(size_type n) const;

Add to the synopsis in [unord.multimap]:

const_local_iterator cbegin(size_type n) const;
const_local_iterator cend(size_type n) const;

Add to the synopsis in [unord.set]:

const_local_iterator cbegin(size_type n) const;
const_local_iterator cend(size_type n) const;

Add to the synopsis in [unord.multiset]:

const_local_iterator cbegin(size_type n) const;
const_local_iterator cend(size_type n) const;

The last version of TR1 does not include the following member functions for unordered containers:

const_local_iterator cbegin(size_type n) const;
const_local_iterator cend(size_type n) const;

which looks like an oversight to me. I've checked th TR1 issues lists and the latest working draft of the C++0x std (N2284) and haven't found any mention to these menfuns or to their absence.

Is this really an oversight, or am I missing something?