Re: [boost] numeric: linear algebra concepts, operator[]

From: boost (boost_at_[hidden])
Date: 2001-03-30 03:16:55

Salut,

On Thursday 29 March 2001 23:56, you wrote:
> Ullrich Koethe wrote:
[...]
>
> operator[] can, of course, return an assignable value. An if you know
> that it does, your algorithms can use 'x[i] = a'. However, truly generic
> algorithms should not be based on this assumption.

I agree.
What about Hermitean or antisymmetric matrices.
Returning an lvalue is a pain. Generally, return lvalues for objects
which have to respect some symmetries an operator[] returning 
an lvalue is problematic. This even applies for vectors, e.g.
you may constraint a vector be normalized, or element of 
a projective space.

Best wishes,
Peter