|
|
Ublas : |
Subject: [ublas] Move Semantics
From: Jesse Perla (jesseperla_at_[hidden])
Date: 2009-08-28 08:24:52
Hi there,
I am writing many routines where I would strongly prefer: matrix<double>
f(const matrix<double>& in) to void f(const matrix<double>& in,
matrix<double>& out )
There has been a lot of discussion about this from the C++ groups:
- The move library to support this in C++03
- http://cpp-next.com/archive/2009/08/want-speed-pass-by-value/
Also, I see that this is native to MTL:
http://www.osl.iu.edu/research/mtl/mtl4/doc/matrix_assignment.html#move_semantics
I don't understand expression templates well enough to know the current
state in ublas, but is it possible to return large matrices in this way?
For example, if I took the following code:
http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?LU_Matrix_Inversionand
had it return a matrix instead, would that give overhead for large
matrices?
Could I even nest it with no overhead in other vector expressions: e.g.
matrix<double> C, B; //setup. Assume they are very large
matrix<double> A = inv(B) + C;
If this pattern is not usable yet, any idea of when it would be?
Thanks,
Jesse