"Maxim Egorushkin" <[EMAIL PROTECTED]> wrote in message news:<[EMAIL PROTECTED]>...
> I don't get the idea of reinventing the stream classes. One can use their > rdbuf() member function to change the buffer. Could you please elaborate on > that?
True, the stream classes are thin wrappers. You don't have to use them if you don't wan't to.
> You have read/write member functions of your source/sink/filter concepts > virtual. If one went for efficiency she would stay away from virtual > functions. With such a design you leave a user no choice.
Source/sink/filter classes don't have to derive from the basic implementations which use virtual functions. The adapters which call the source/sink/filters know the fully-derived types of the source/sink/filters and shouldn't have to use virtual function dispatch. There does seem to be a need for one non-inlinable function at each junction, if non-trivial filtering is taking place. I address this in the efiiciency section.
> There are too many adapters, IMHO. It obscures. Since each STL sequence > support iterators why don't use it? Generally speaking, there should be only > two adapters (input and output) that take any STL sequence represented by > begin/end iterators.
The factory functions address this. You just call new_source or new_sink with whatever object you want to make into a source/sink. This is less verbose than using, e.g., streambuf iterators. Also, in the case of strings, the factories return adapters which are better than generic container adapters; with SFINAE you should be able to pass a string literal to new_source.
Examples:
new_source<char>(v); // simpler than using
// iterator_source< vector<char>::iterator
>(v.begin(), v.end())
new_sink<char>(sb); // simpler than using
// iterator_source< ostreambu_iterator<char> >
// ( ostreambuf_iterator<char>(sb),
streambuf_iterator<char>() );
new_source<char>("hello"); // simpler than string h("hello");
// iterator_source(h.begin(), h.end()).
...
> P.S. There is a very good article by Alexandre Duret-Lutz and Thierry Geraud > " > Improving Object-Oriented Generic Programming".
I'll look at it. Thanks.
_______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
