
Boost : 
From: Vladimir Prus (ghost_at_[hidden])
Date: 20011112 04:23:41
Aleksey Gurtovoy wrote:
> For all algorithms that take an iterator pair (i.e. two iterator
> parameters that designate a single input/forward/etc. sequence) it
> makes sense and is very practical to have a version (wrapper) that
> takes a single sequence argument  a model of Sequence concept,
> e.g.
> template<typename InputSequence, typename UnaryFunction>
> inline
> UnaryFunction
> for_each(InputSequence const& seq, UnaryFunction const& f)
> {
> return std::for_each(
> boost::begin(seq)
> , boost::end(seq)
> , f
> );
> }
There are two problems, good solutions for which I'm yet to hear:
1. std::adjacent_find(ForwardIterator, ForwardIterator);
std::adjacent_find(ForwardIterator, ForwardIterator,
BinaryPredicate);
When
adjacent_find(const Sequence&);
adjacent_find(const Sequence&, BinaryPredicate)
are added, there will be ambiguity when calling the function with
two arguments, won't it?
2. What will you do about mutating algorithms?
sort(Sequence&);
Somebody then writes:
... filter(const Sequence&, Predicate);
sort(filter(v, <some functional object>));
But oops! filter returns rvalue, which can't be bound to nonconst
reference. The only possibility is to specialize algorithm for
derivatives of some fixed class.
Regards,
Vladimir
Boost list run by bdawes at acm.org, gregod at cs.rpi.edu, cpdaniel at pacbell.net, john at johnmaddock.co.uk