On 18/06/20 07:34 +0100, Richard Sandiford wrote:
Thanks for the comments, just had a question about one of them…
Jonathan Wakely <jwak...@redhat.com> writes:
On 16/06/20 15:14 +0100, Richard Sandiford wrote:
Martin Li?ka <mli...@suse.cz> writes:
On 6/16/20 10:50 AM, Richard Sandiford wrote:
Hmm, sounds like a nice abstraction but I see 2 problems with that:
1) How can I define a constructor of the iterator_pair when I need something
like:
iterator_pair<const_iterator> (region_begin, region_end)?
Not sure if I'm answering the right question, sorry, but I meant
something along the lines of:
template<typename T>
struct iterator_pair
{
public:
iterator_pair (const T &begin, const T &end)
: m_begin (begin), m_end (end) {}
T begin () const { return m_begin; }
T end () const { return m_end; }
private:
T m_begin;
T m_end;
};
You could also add an "object generator" for that type:
template<typename T>
iterator_range<T>
make_iterator_range(T begin, T end)
{
return iterator_range<T>(begin, end);
}
This deduces the type T from the function arguments, so will allow you
to write:
return make_iterator_range(x, y);
instead of:
return iterator_range<const_iterator>(x, y);
i.e. you don't need to say <const_iterator> because the compiler can
deduce it from the arguments.
In Martin's case the x and y arguments don't naturally have type
const_iterator, so I guess this would become:
return make_iterator_range (const_iterator (x), const_iterator (y));
Ah yes, of course..
Is that more idiomatic than:
return iterator_range<const_iterator> (x, y);
?
Idiomatic or not, the make_iterator_range function is more verbose, so
defeats the purpose of using it.
