Is there a sensible way to write the contents of one stream to another?
I know

ostream.write(istream.read)

works, and it reads nice, but the entire contents of istream is loaded
into memory, and that is not always reasonable.

I think the least surprising thing would be for 

ostream.write(istream)

to write the contents of istream to ostream. The same goes for ostream
<< istream.

Thomas