On Wed, Jun 17, 2015 at 11:13:58AM +0200, Martin Jambor wrote:
> > >> Do you mean Richard following changes:
> > >>
> > >> alloc-pool.h (allocate):
> > >> ...
> > >> + /* Placement new contructor. */
> > >> + inline void *operator new (size_t, elt_loc_list *&ptr)
> > >> + {
> > >> + return ptr;
> > >> + }
> > >
> > > That should be there with including <new>
> > >
> > >> and e.g. cselib.h:
> > >>
> > >> struct cselib_val
> > >> {
> > >> /* Pool allocation new operator. */
> > >> inline void *operator new (size_t)
> > >> {
> > >> return pool.allocate ();
> > >> }
> > >>
> > >> /* Placement new contructor. */
> > >> inline void *operator new (size_t, char *&ptr)
> > >> {
> > >> return ptr;
> > >> }
> > >
> > > Yes, though I wonder whether cselib_val should really have undefined
> > > contents after
> > > allocating it? (or does the pool allocator zero the memory?)
IMHO if you want to put placement new into allocate, then you probably need
two different methods, one that will return you just void * to the
allocated memory chunk that you should use
inline void *operator new (size_t) { return pool.allocate (); } on,
and another method that will use that and additionally invoke a placement
new on it and return you the constructed pointer, which you'd use elsewhere.
Otherwise you'd construct the object twice...
Jakub
