Re: [boost] ublas matrix::swap problem

From: boost (boost_at_[hidden])
Date: 2002-04-17 16:48:17

Dear Jörg,

On Wednesday 17 April 2002 21:23, Joerg Walter wrote:

> The precondition, that the sizes of the matrices shall be identical, is
> checked, because swap() is used in assign_temporary(). May be, we could
> move the precondition checks to assign_temporary().
If they are needed there, I'd move them.

>
> But swap() for matrix views like matrix_range<> is intended to have deep
> semantics similar to assignment, i.e. swap() should swap the elements of
> the referenced matrices, but not the views. Here the precondition seems to
> be reasonable.
Mmhh, why ? SInce the views are references to parts of a matrix,
I'd expect them to change after calling swap().

> So the interesting question arises, whether container and views should
> require the same precondition on swap() or container's swap() should be
> allowed to swap different sized matrices, too.

Container should be allowed to swap to different sized matrices, since
that's what we're used from STL. 

Best wishes,
Peter