Boost logo

Ublas :

From: Gunter Winkler (guwi17_at_[hidden])
Date: 2007-04-17 16:49:13

Am Dienstag, 17. April 2007 20:14 schrieb Neal Becker:
> Any clue about the feasibility of making the ublas functions
> real/imag into lvalues, so we could say:
> real (z) = w
> where z is a vector<complex> and w is vector<double>, for example

The difference between range(M, i, k) and real(M) is that the first is a
proxy and the second is just a simple expression template. In order to
get such assignments work you have to create a (mutable) proxy class
like range() instead of the current vector_unary. Maybe you extend
vector_unary to a mutable_vector_unary by adding some non-const

Alternatively you can try to do something like the noalias() proxy,
which essentially maps operator=() to assign() such that your proxy
maps operator=() to some real_assign(). (This may be work by simply
adding scalar_real_assign similar to scalar_plus_assign and using
vector_assign<scalar_real_assign>(x,y) )


PS: What about reinterpreting as n-by-2 dense row-major matrix
and using the column proxy?
(note to myself: this would be a nice example of matrix, array_adaptor
and column.)