Created on 2021-10-31.00:00:00 last changed 3 weeks ago
template<class ForwardIterator> basic_regex(ForwardIterator first, ForwardIterator last, flag_type f = regex_constants::ECMAScript);
template<class InputIterator> basic_regex& assign(InputIterator first, InputIterator last, flag_type f = regex_constants::ECMAScript);
Ignoring the lack of proper requirements (which is LWG 3341),
why does the constructor take forward iterators,
but the assign function takes input iterators?
Why could construction from input iterators not be implemented as simply
assign(first, last, f)?
The current constructor signature is the result of N2409
which was resolving LWG 682.
It looks like the
assign function should have been changed
at the same time, to keep them consistent.
I see no reason why they can't both take input iterators.
The meta-programming needed to avoid an additional string copy for the
input iterator case is trivial with
and C++20 iterator concepts.