Re: [Boost-users] How to inherit from boost::multi_array

From: Yan Zhang (Yan.Zhang_at_[hidden])
Date: 2005-06-06 12:09:38

I'm read the posting by Thomas and replay by Ronald on how to inherit
from boost::multi_array as following:
 
 
On Oct 2, 2004, at 10:26 AM, Thomas Mensch wrote:
 
Dear List,
 
I am using boost 1.31.0 on Linux (with gcc 3.3.2)
I would like to create a 2D array class, which inherits  from
boost::multi_array<double, 2> class. However I have problems
with the copy constructor of my class Array.  Below is the code,
which I am trying to run.
 

#include <boost/multi_array.hpp>

class Array
: public boost::multi_array<double,2>
{
public:
Array (void) :
boost::multi_array<double, 2> ()
{}

Array (const int nrow, const int ncol) :
boost::multi_array<double, 2> (boost::extents[nrow][ncol])
{}

Array (const Array& other) :
boost::multi_array<double, 2> (other)
{}

~Array (void)
{}

Array& operator= (const Array& rhs)
{
if (&rhs != this)
{
boost::multi_array<double, 2>::operator= (rhs);
}
return *this;
}
}; /* class Array */

 

 

Ronald's replay: 

Greetings Thomas,

Though you did not supply the error message from your compiler, I
suspect that the problem is this: multi_array has a templated
constructor of the form:
template <class T> multi_array(T const&);

that will match your Array type better than the constructor with the
signature:

multi_array(multi_array<double,2> const&);

In short, overload resolution is not selecting the constructor that you
desire. You'll need to coerce your Array reference to a
multi_array<double,2> reference before passing it to the constructor.

Hope this helps.

I had the same problem as Thomas'. I don't quit understand Ronald's
comment. How to you overload template <class T> multi_array(T const&)
instead of multi_array(multi_array<double,2> const&)? I thought Thomas'
code is overloading template <class T> multi_array(T const&).

 

Thanks in advance,

 

Yan