Re: [ublas] bounded_matrix declaration only

Subject: Re: [ublas] bounded_matrix declaration only
From: Benson Margulies (bimargulies_at_[hidden])
Date: 2008-11-15 17:17:53

Declare it as a pointer, use new when you know the size.

On Sat, Nov 15, 2008 at 5:11 PM, Vardan Akopian <vakopian_at_[hidden]> wrote:
> On Sat, Nov 15, 2008 at 7:00 AM, Moritz Beber
> <moritz.beber_at_[hidden]> wrote:
>> Dear members,
>> I'm trying to use the bounded_matrix as a member variable for a class
>> I'm currently designing. The declaration of it gives me troubles though
>> since the way I'm currently approaching it, it would require size
>> information for the declaration already while I naturally only have that
>> information available at the point of construction of an object of that
>> class. A default constructor where that info is not available yet is
>> another story also.
>> I suppose I could use a normal matrix but since the size of the matrix
>> will not change at all during the existence time of the class object I
>> thought a bounded_matrix would make sense.
>>
>> So the code I had in mind would look somewhat like this:
>>
>> myclass {
>>        bounded_matrix<double, M, N, column_major> m;
>>        ...
>> }
>>
>> myclass::myclass(unsigned int rows, unsigned int cols)
>> {
>>        m = bounded_matrix<double, rows, cols, column_major>(rows, cols);
>>        ...
>> }
>>
>> Is there a way to bypass the need to give specific size information at
>> the time of declaration?
>>
>> Thank you for your insights,
>> Moritz
>>
>> _______________________________________________
>> ublas mailing list
>> ublas_at_[hidden]
>> http://lists.boost.org/mailman/listinfo.cgi/ublas
>>
>
> Moritz,
>
> Template parameters have to be known at compile time.
> Just because the matrix size does not change during its existence,
> does not mean that it is known at compile time. So your code above
> cannot work with bounded_matrix. You either need to use
> unbounded_matrix, or you'd need to make your class a template class as
> well. The latter only moves the issue to another place (where you'd
> need to instantiate myclass), so if in principle the dimensions are
> not known at compile time, this solution will not work and you'd still
> have to go with unbounded_matrix.
>
> Hope it helps
> -Vardan
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