Sounds confusing to me. Does it have to be a constructor? What's wrong with a shallow_copy() function?
Martin On 22 February 2013 14:25, Johan Hake <hake....@gmail.com> wrote: > On 02/22/2013 02:18 PM, Garth N. Wells wrote: > > On 22 February 2013 13:13, Johan Hake <hake....@gmail.com> wrote: > >> Any comment on this? > >> > >> Basically we need another constructor which generates a shallow copy of > >> a Function, which also has access to the original Function. > >> > > > > Would this be a non-issue if using a shared_ptr? What's the difference > > between a shallow copy of a Function and a pointer to a Function? > > The shared_ptr is just a way to differ a deep copy from a shallow copy. > Using a shared_ptr is really just an abuse of syntax. The shared_ptr > will not be passed to the new Function anyhow. There might be other ways > to differentiate these two constructors from each others. The obvious > being: > > Function(const Function& other, bool deepcopy) > > but not sure that is any better... > > The reason we need this in the first place is to be able to generate a > Python wrapped version of a Function when such is returned from the C++ > interface. With a shallow copy constructor we minimize the amount of > copying. > > Johan > > > Garth > > > >> Johan > >> > >> On 02/21/2013 07:08 PM, Johan Hake wrote: > >>> Hello! > >>> > >>> To fix: > >>> > >>> [child().child() fails for Function and FunctionSpaces in Python] > >>> https://bugs.launchpad.net/bugs/1130354 > >>> > >>> we need to add a way of shallow copy a Function. For now we have used: > >>> > >>> Function(boost::shared_ptr<const FunctionSpace> V, > >>> boost::shared_ptr<GenericVector> x); > >>> > >>> Which create a new Function with a shared FunctionSpace and > >>> GenericVector. The problem is that there is no way of bringing > >>> Hierarchical data to the new Function as it is not passed through the > >>> constructor. > >>> > >>> We would need something like: > >>> > >>> Function(boost::shared_ptr<const Function> u); > >>> > >>> which is interpreted as a shallow copy. > >>> > >>> We could then map this to: > >>> > >>> Function._shallow_copy() > >>> > >>> and > >>> > >>> Function(const Function& u); > >>> > >>> to > >>> > >>> Function._deep_copy() > >>> > >>> in the Python interface. Then we add: > >>> > >>> Function. > >>> > >>> def copy(self, deepcopy=True): > >>> if deepcopy: > >>> return self._deep_copy() > >>> else: > >>> return self._shallow_copy() > >>> > >>> Any objections to adding: > >>> > >>> Function(boost::shared_ptr<const Function> u); > >>> > >>> as a shallow copy constructor? > >>> > >>> If so we could maybe remove: > >>> > >>> Function(boost::shared_ptr<const FunctionSpace> V, > >>> boost::shared_ptr<GenericVector> x); > >>> > >>> as I think we added it so we could create a shallow copy in the Python > >>> interface. > >>> > >>> Johan > >>> > >> > >> > >> _______________________________________________ > >> Mailing list: https://launchpad.net/~dolfin > >> Post to : dolfin@lists.launchpad.net > >> Unsubscribe : https://launchpad.net/~dolfin > >> More help : https://help.launchpad.net/ListHelp > > > _______________________________________________ > Mailing list: https://launchpad.net/~dolfin > Post to : dolfin@lists.launchpad.net > Unsubscribe : https://launchpad.net/~dolfin > More help : https://help.launchpad.net/ListHelp >
_______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : dolfin@lists.launchpad.net Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
