Re: [boost] Re: Fxns as io::filters

From: Jonathan Wakely (cow_at_[hidden])
Date: 2005-01-11 07:31:41

On Mon, Jan 10, 2005 at 04:52:58PM -0700, Jonathan Turkanis wrote:

> christopher diggins wrote:
> > I mentioned in an earlier response to JT that I have written a
> > function to filter adapter. The entire code is now online at
> > http://www.cdiggins.com/iostreams_fxn_filters.hpp
> >
> > I can't help but wonder if the syntax for chaining streams to filters
> > shouldn't be
> >
> >   cin >> fxn_filter(fxn) >> cout;
> >
> > instead of
> >
> >   cin | fxn_filter(fxn) | cout;
> >
> > Anyone have any thoughts on the subject? Would anyone else, other
> > than me, like to see this functionality added to iostreams?
> 
> I certainly wouldn't want two operators that do the same thing. So the question
> is whether to replace | with >>. Following JC van Winkel and John van Krieken, I
> chose | because of the close analogy with the UNIX pipe operator. Another reason
> is that someone might want to write inserters and extractors for a filter or
> device type, which would then interfere with the piping mechanism. Also
> 
>       xxx >> cout
> 
> looks like an error to me.

I strongly agree. Using operator| makes it clear something other than
standard IOStream syntax is being used.

jon

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