Hi !

Studying the draft sections about VALARRAY, several questions came up to me.

- how can I pass the 'raw data' to a C or FORTRAN function?
  As far as I understand 26.3.2.3(3) it should be safe to pass &V[0]
  (if V is a valarray)  BUT this seems to be guarantueed for non-const
  valarrays. How can I pass a const valarray. Probably I cannot
  rely on  &V == &V[0] !?  Can I still rely on  &V[0] pointing to the
  first element of the array?

- How efficient is the constructor  valarray( const slice_array<T>& ) ?
  As far as I understand, there are no operators which apply to a
  slice_array directly. So doing  S+T  where S and T are slices of
  equal length, the compiler must convert to valarray first.
  Now I wonder wether an implementation of the conversion can be done
  without copying. If it should imply copying it is a pity since
  copying is as expensive as adding.

- Why doesn't have the 3rd argument of 'slice' (stride) a default
  value of 1. It will be used this way most of the time and I am not
  sure if the compiler optimizes it as if there were no 3rd argument.

Thanks for your comments,

---
Helmut Jarausch
Lehrstuhl f. Numerische Mathematik
Institute of Technology
RWTH Aachen
D 52056 Aachen, Germany
---
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