According to the description given in 28.10/2 the class template
match_results "shall satisfy the requirements of a Sequence, [..],
except that only operations defined for const-qualified Sequences
are supported".
Comparing the provided operations from 28.10/3 with the sequence
/container tables 80 and 81 one recognizes the following
missing operations:

1) The members

const_iterator rbegin() const;
const_iterator rend() const;

should exists because 23.1/10 demands these for containers
(all sequences are containers) which support bidirectional
iterators. Aren't these supported by match_result? This is not
explicitely expressed, but it's somewhat implied by two arguments:
(a) Several typedefs delegate to
iterator_traits<BidirectionalIterator>.
(b) The existence of const_reference operator[](size_type n) const
implies even random-access iteration.
I also suggest, that match_result should explicitly mention,
which minimum iterator category is supported and if this does
not include random-access the existence of operator[] is
somewhat questionable.
Furtheron it seems somewhat deliberate to provide operator[]
but not the at()/front()/back() members which all four belong
to the optional sequence operations of table 83.

2) The new "convenience" members

const_iterator cbegin() const;
const_iterator cend() const;
const_iterator crbegin() const;
const_iterator crend() const;

should be added according to tables 80/81.

Greetings from Bremen,

Daniel Kr   gler


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> Furtheron it seems somewhat deliberate to provide operator[]
> but not the at()/front()/back() members which all four belong
> to the optional sequence operations of table 83.

Sorry for this one: I see now that at() is really not needed.

Daniel

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