[Freeciv-Dev] Re: TODO

[Jules Bean <jules@xxxxxxxxxxxxxxxxxxxxxxxxx>]

On Fri, Sep 22, 2000 at 12:45:45PM +0200, Raimar Falke wrote:
> On Fri, Sep 22, 2000 at 10:56:58AM +0100, Jules Bean wrote:
> > Instead use a 'constructor' function
> > 
> > struct locus make_locus(int x,int y) {
> >   struct locus l;
> >   l.x=x; l.y=y;
> >   return l;
> > }
> 
> AFAIK this is wrong. The variable l is created on the stack which is
> destroyed at the return. You have to do return a newly allocated part of
> memory. Using this you will get some problems with bookkeeping since C has
> no GC.

Nope.

The above will make another copy of 'l' and return that.

I'm not returning a pointer to l, I'm returning l itself, which is a
copying operation.  At no point do I use pointers, so I cannot trip
over destroyed memory errors.

Some compilers will in fact optimise out the copy, but that's their
problem (and it's a good thing, if they do it correctly ;-)

Jules