[ublas] Intel compiler / Visual Studio 2005 SP1 errors with Vector and Matrix

From: Chris Bevan (chris_at_[hidden])
Date: 2008-02-26 11:46:21

Hi all,

We recently encountered an error compiling uBLAS on Windows with a  
combination of the Intel compiler v9.1 and the libraries and headers  
from Visual Studio 2005 SP1.  I've seen this error reported by others  
but didn't find a response, so thought I'd post my findings here.

Firstly, I'm not sure whether this is more of an issue with uBLAS,  
the Intel compiler, or VS2005 SP1, as any other combination seems  
completely fine.  As uBLAS is the only thing I could practically  
change, I've modified the appropriate files - vector.hpp and  
matrix.hpp - to get around the error.

Have a look at this example programme:
#include <boost/numeric/ublas/vector.hpp>

typedef boost::numeric::ublas::c_vector<int, 2> Vec;

void VecFn(const Vec& a)
{
   Vec b(a);
}
It produces the following error when compiled with the configuration  
mentioned above:
boost/numeric/ublas/vector.hpp(1302): error: more than one instance  
of overloaded function "std::copy" matches the argument list:
             function template "_OutElem *__cdecl std::copy(_InIt,  
_InIt, _OutElem (&)[_Size])"
             function template "std::_Enable_if<<expression>,  
_OutIt>::_Result __cdecl std::copy(_InIt, _InIt, _OutIt)"
             argument types are: (const  
boost::numeric::ublas::c_vector<int, 2U>::array_type, const  
boost::numeric::ublas::c_vector<int, 2U>::value_type *,  
boost::numeric::ublas::c_vector<int, 2U>::array_type)
               std::copy (v.data_, v.data_ + v.size_, data_);
               ^
           detected during:
             instantiation of "boost::numeric::ublas::c_vector<T, N>  
&boost::numeric::ublas::c_vector<T, N>::operator=(const  
boost::numeric::ublas::c_vector<T, N> &) [with T=int, N=2U]" at line  
1216
             instantiation of "boost::numeric::ublas::c_vector<T,  
N>::c_vector(const boost::numeric::ublas::c_vector<T, N> &) [with  
T=int, N=2U]"
The ambiguity between an array reference or a pointer to the first  
element of the array is causing problems here.  I've attached a  
unified diff that fixes the problem for me.  It's a simple change,  
but not a particularly elegant one, as I haven't really worked with  
the library myself otherwise.  The error comes up in a few other  
places depending on which methods are used, and no doubt there are  
more that I haven't looked into.

Maybe someone else more experienced with the code could suggest a  
better solution, but anyway I thought it might help to post the issue  
in case someone else experiences something similar.

Cheers,

- Chris Bevan