Re: [ublas] How to use "int" for index values in debug configuration?

From: Gunter Winkler (guwi17_at_[hidden])
Date: 2006-10-16 04:29:07

On Saturday 14 October 2006 10:07, wangxiaoyi wrote:
> The uBLAS uses *size_t* to for index values. However, I have use int as
> the index values in some cases. For example, I have to use int indexed
> sparse matrix when binding ublas matrix to superLU package. Using int as
> index value may fail to compile in debug configuration, i.e. no NDEBUG
> defined. The compiler reports that:
> NO function could match same_impl_ex(int, size_t). Actually in
> exception.hpp:276, same_impl_ex is just defined for the argument type,
> expected to be (size_t, size_t).
>
> Is there really a way to use int as index value in current released ublas?

The use of int instead of size_t is not fully working, but it should work with 
most expression. Only mixing of index types makes lots of trouble. It looks 
like you operated on two different types of vectors/matrices. If you need 
(int) as index type you always have to use the full type declaration

vector<double, A> where A is an allocator type, that defines the size_type as 
(int).

This is quite nasty and may still be fail on some expressions.

A workaround is to give a specialization of same_impl_ex (untested)

    template<class T>
    BOOST_UBLAS_INLINE
    size_t same_impl_ex (const size_t &size1, const int &size2, 
                         const char *file, int line) {
        BOOST_UBLAS_CHECK_EX (size1 == size2, file, line, bad_argument ());
        // WARNING: this fails if size2 is negative!
        return (size1<size2?(size_t)size1:(size_t)size2);
    }

mfg
Gunter