Re: [boost] [PQS] rank of a physical quantity?

From: Frederick Akalin (akalin_at_[hidden])
Date: 2006-06-19 23:30:00

> Having rank also solves the following problem I was wondering about: how
> do you define vector scalar multiplication in a sufficiently restrictive
> way.  Without a notion of rank, matrix * vector could be ambiguous with
> scalar * vector since (matrix * x, matrix * y, matrix * z) would be a 
> valid
> vector<matrix<T> >.
>
>   
Perhaps I'm horribly misunderstanding something, but wouldn't the fact 
that "matrix<T> * vector<T>" has to return "vector<T>" be enough to 
disambiguate it?  Your example is implying that matrix<T> * vector<T> 
can somehow return vector<matrix<T> >.

Frederick Akalin