Jeff Flinn skrev:

David Abrahams wrote:

...

in 1.35 I'm pretty sure that iterator_range<T>::size() only works when T is a random access iterator, and filtered iterators are by necessity bidirectional. I suggest you use

std::distance(r.begin(), r.end())

if you're willing to pay for O(N) execution.

Hmm, it looks like that's what iterator_range<T>::size() did in 1.34.1 while 1.35 returns m_Begin - m_End. Any idea why this was done?

boost::distance(r) could also work. I did it as part of the general clean-up of the range lib. size() is expected to be O(1) by users, distance() is not. -Thorsten