Re: [Boost-users] [iostreams] how to say a filter is closable

From: Jonathan Turkanis (turkanis_at_[hidden])
Date: 2008-01-08 16:12:21

frederic.bron_at_[hidden] wrote:
> 
> 
> I want to write a filter but this filter needs to do some things when the stream is ending.
> Is it enough to do the following? I want the close function to be called at the end of the stream.
> Do I need to category_flag to inherit from (closable_tag)?
> 
> class my_filter : public io::dual_use_filter {
>         public:
>                 template<typename Source> int get(Source&) ;
>                 template<typename Sink> bool put(Sink&, int) ;
>                 template<typename Device> void close(Device&, std::ios_base::openmode) ;
> } ;

Hi Fred,

Eric is correct: the convenience base class dual_use_filter has category 
convertible to closable_tag, and a no-op implementation of close.

-- 
Jonathan Turkanis
CodeRage
http://www.coderage.com