Complex-Real iterator adaptors (again)

From: nbecker_at_[hidden]
Date: 2001-11-20 09:08:46

Since iterator_adaptors has been improved, now I can implement
complex->real iterator adaptors.  Thanks!

Very useful things you can do:

1) convert a complex stream to a scalar stream, where the scalar picks
   up real and imag parts alternately.  This requires the adaptor to
   hold state.

2) pick off just the real (or just imag) part of a complex stream.
   This is implemented easily just using transform_iterator.

Things I don't know how to do (yet):

1) Combined two scalar streams into a complex.  This is like an
   iterator adaptor, but with two inputs.

Here's a couple of simple examples: