On Sun, Nov 23, 2008 at 13:06, Daniel Walker <daniel.j.walker@gmail.com> wrote:
On Sun, Nov 23, 2008 at 1:49 AM, David Abrahams <dave@boostpro.com> wrote: <snip>
Frankly, you don't even need to be that explicit: just write the semantics of empty as
begin(r) == end(r)
That was the definition of the semantics of empty(r) before it was (inexplicably) removed from the Range concept.
And despite not being mentioned in the concept (http://www.boost.org/doc/libs/1_37_0/libs/range/doc/range.html#single_pass_r... and boost/range/concepts.hpp), it's still in the Semantics section of the "Synopsis and Reference" page (http://www.boost.org/doc/libs/1_37_0/libs/range/doc/boost_range.html#Semanti...). In fact, why does iterator_range have a public empty() method at all? It's modelling a range, so boost::empty will use boost::begin and boost::end, completely ignoring iterator_range<T>::empty. Making ir.empty() just sugar for boost::empty(ir) seems the only reasonable way to avoid consistency problems. (Removing the member altogether would be nice, but it's probably too late for that.)