[Boost-users] [iostreams] Prepending and appending output data in a filter

From: Edward Diener (eldiener_at_[hidden])
Date: 2008-04-28 12:31:38

I have a filter, derived from multichar_output_filter, in which I am 
both prepending data and appending data. In other words the data being 
written to the sink will be greater than the data being passed into the 
       filter's 'template<typename Sink> std::streamsize write(Sink& 
dest, const char* s, std::streamsize n)' member function, which my 
filter is implementing.

Is this an allowable use of filters ?

Do I still return the 'n' streamsize data being passed in or do I return 
the actual length of the data being written ?

Can I use the

'template<typename T> std::streamsize write( T& t, const typename 
char_type_of<T>::type* s, std::streamsize n );'

function to write the data, or do I need to 'put' each character to the 
sink using the

'template<typename Sink> void put(Sink& snk, typename 
char_type_of<Sink>::type c);'

function instead ?