Re: Number/Algebraic concepts (was RE: [boost] RE: rational.hpp)

From: Doug Gregor (gregod_at_[hidden])
Date: 2001-01-13 21:03:10

On Saturday 13 January 2001 08:35, you wrote:
> Hi Doug,
>
> Thanks for the explanation.
>
> How about the case when the matrix size is a run-time value, instead
> of compile-time as in your example?

Our notion of literal tables can't handle run-time values. They were designed 
to be analagous to C++ literals (int, float, string, bool, etc) for 
high-level compiler optimizations and as such must be generated using only 
static information. 

However, Boost doesn't need the same functionality that literal tables were 
designed for. Instead of literal tables, a one-way mapping from ID to value 
could be used. Then, additional parameters could be specified at run-time:

template<typename Domain, int ID>
struct GetLiteral
{
  static Domain get() { /* ... */ }  
};

This would allow something like:

template<typename T>
struct GetLiteral<Matrix<T>, 1>
{
  static Matrix<T> get(int rows, int cols) { 
        return Matrix<T>(rows, cols, Matrix<T>::identity);
  }
};

        Doug Gregor
        gregod_at_[hidden]