Re: [ublas] boost::numeric::ublas::matrix_slice assignment operator Newbie question - update

From: Gunter Winkler (guwi17_at_[hidden])
Date: 2006-06-19 05:58:16

Sorry, I mixed up something. Forget about my last post.

On Monday 19 June 2006 11:46, Gunter Winkler wrote:

>         BOOST_UBLAS_INLINE
>         matrix_slice &operator = (const matrix_slice &ms) {
>             matrix_assign<scalar_assign> (*this, ms);
>             return *this;
>         }

matrix_slice _always_ assigns the data of the matrix. You can only create a 
(sub-)slice of the slice or use a new name. 

{ 
  matrix_slice ms( ... )
  do something
} // ms goes out of scope
{ 
  matrix_slice ms( ... )
  do something more
}
alternatively you can alway use 
project( M, slice(...), slice(...) ) = project( M, slice(..), slice(...) );

>         BOOST_UBLAS_INLINE
>         matrix_slice &assign_temporary (matrix_slice &ms) {
>             return *this = ms;
>         }

this calls the above assignement operator and there copies some data of the 
matrix.

mfg
Gunter