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Subject: Re: [Boost-users] begin (cout) or boost::copy to cout
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2011-09-13 20:48:19


On 09/13/2011 05:41 PM, Nathan Ridge wrote:
>> This function eliminats the need of passing explicit template parameters to
>> std:: ostream_iterator, which makes the code fragile and hard to read.
> I agree that having to pass a template parameter to std::ostream_iterator
> is annoying.
> However, overloading boost::begin for std::ostream is not a good solution,
> because, as Steven pointed out, ostream is not a range. (And certainly,
> overloading boost:copy for something as specific as std::ostream is
> not a good solution - it goes directly against the spirit of generic
> programming, which is to express algorithms in terms of a generic
> interface (iterators), and have data structures adapt to that interface).
> A better solution is to write a polymorphic version of ostream_iterator;
> that is, a version that's not a template, but which has a templated
> operator=, so that you can output any type using the iterator.

I suspect that it would be difficult to
make a valid STL iterator like that.
How would you define std::iterator_traits
for it?

> With such a modified ostream_iterator, you can write:
> boost:copy(some_range, my_ostream_iterator(cout, " "));
> which is very close to what you are aiming for.

In Christ,
Steven Watanabe

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