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From: Anatoli Tubman (anatoli_at_[hidden])
Date: 2004-04-22 09:23:14

John Torjo wrote:
> However, had I used
> crange<int> r(d); // how do I know what iterators to keep inside?
> crange<int> r(v); // how do I know what iterators to keep inside?

You keep a pointer to crange_impl_base<int> which points to a
heap-allocated instance of crange_impl<int, d_array> (or
crange_impl<int, v_array> or what have you) which is derived from
crange_impl_base<int> and knows what iterators to keep inside. Not very
efficient, but not technically impossible either.

Another option is to write

   for (crange<int>& r = mkrange(d); r; ++r) { ... }

where mkrange returns crange_impl<int, d_array> which is derived from

This doesn't need heap allocation, but still needs virtual operator++
and virtual operator*. A smart compiler could in theory inline them
anyway, but I wouldn't count on it.

Anatoli Tubman
PTC Israel (Haifa)
Tel. (+972) 4-8550035 ext. 229

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