[Python-ideas] generic Ref class

[Aaron Brady]

> -----Original Message-----
> From: python-ideas-bounces at python.org [mailto:python-ideas-
> bounces at python.org] On Behalf Of Aaron Brady
> 
> > -----Original Message-----
> > From: python-ideas-bounces+castironpi=comcast.net at python.org
> > [mailto:python-ideas-bounces+castironpi=comcast.net at python.org] On
> Behalf
> > Of Adam Atlas
> >
> > On 12 Jan 2008, at 15:03, Aaron Brady wrote:
> > > Then:
> > >
> > > 	for x in refs( listA ):
> > > 		x.val+= 1
> > >
> > > Better than:
> > >
> > > 	for i, x in enumerate( listA ):
> > > 		listA[i]= x+ 1
> >
> > Don't these do different things? The latter modifies the original
> > list, while the former, with your Ref class, apparently modifies (in a
> > by-reference sense) a new list that is thrown away once the for loop
> > is done.
> 
> Ah yes.  Say:
> 
> 	listA= refs( range( 20 ) ) #or your list
> 
> then:
> 
> 	for x in listA:
> 		x.val+= 1
> 
> Slightly slower, but useful in addition to pass to functions too:
> 
> 	def squareanint( intref ):
> 		intref.val**= 2
> 
> 	a= 2
> 	squareanint( a )
> 	print a

And once again, I typo:

 	a= 2
 	squareanint( Ref( a ) )
 	print a