From: David Abrahams (dave_at_[hidden])
Date: 2003-10-11 07:12:34
"Thorsten Ottosen" <nesotto_at_[hidden]> writes:
> Brian, thanks for your cat and dog example; the thing is that it could be
> necessary to sort polymorphic types or that Base is not polymophic. Anyway,
> the hard thing is to make the copy copy pointers and not objects. The easy
> (which I'm leaning a little towards ) is simply to provide normal iterators:
> struct ptr_less_than
> template< typename T >
> bool operator()( const T*l, const T* r)
> *l < *r;
> sort( v.ptr_begin(), v.ptr_end(), ptr_less_than() );
That is also the correct solution.
There's a way to get the effect you want with the new iterator
adaptors using a proxy reference type, provided, of course, that your
stdlib's sort doesn't check to make sure it has an lvalue iterator.
Its harder and probably less efficient than the above.
-- Dave Abrahams Boost Consulting www.boost-consulting.com
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