On Sat, Feb 14, 2009 at 6:08 PM, Johan Hake <[email protected]> wrote: > On Saturday 14 February 2009 17:45:44 Martin Sandve Alnæs wrote: >> On Sat, Feb 14, 2009 at 5:34 PM, Johan Hake <[email protected]> wrote: >> > On Saturday 14 February 2009 17:28:18 Garth N. Wells wrote: >> >> Johan Hake wrote: >> >> > On Saturday 14 February 2009 13:48:05 A Navaei wrote: >> >> >> It seems that the error can be re-produced even without sub-classing >> >> >> and using existing dolfin classes in pure c++. Based on the >> >> >> itk-dolfin interface code, the below minimal code should generate the >> >> >> error (note that I use the binary distribution which uses std::tr1, >> >> >> replacing it with boost shared pointer should not have any effect). >> >> > >> >> > Not in c++ but swig only support std::tr1::shared_ptr from version >> >> > 1.3.37. But if you intend to use shared_ptr only internally there >> >> > whould not be any problems. >> >> > >> >> >> After wrapping in python: >> >> >> >> >> >> (1) Calling FunctionTest.CreateFunction(), which returns by value, >> >> >> results this error: >> >> >> >> >> >> RuntimeError: *** Error: Unable to assign to function, missing >> >> >> coefficients (user-defined function). >> >> > >> >> > You cannot assign another user-defined function to another Function. >> >> > It must be a discrete function, which has an initialized _vector. This >> >> > is probably a feature that other developers should answer for. >> >> > >> >> > However this means that you cannot copy a userdefined function, with >> >> > the side effect of not beeing able to return a user-defined Function >> >> > by value. >> >> > >> >> >> Since dolfin::Function does come with the required copy ctors, the >> >> >> problem cannot be stemmed from this. >> >> > >> >> > This use the assignment operator which requires the Function to be a >> >> > discrete and not a user-defined Function. >> >> > >> >> > I consider this to be a bug in the library. Any other comments from >> >> > the C++ DOLFIN developers (I am mostly dealing with the python >> >> > interface)? >> >> >> >> In a nutshell, are you suggesting that the Function copy constructor >> >> should work for user-defined Functions? >> > >> > Yes. Why shouldn't it? >> > >> > I can see why the assigment operator should not work. >> >> If I understand this right, what you propose is probably not >> technically possible in C++ with the current design. The old design >> which used the envelope-letter could have dealt with this. > > Why's that? > > The only data that needs to be copied are the FunctionSpace, when _vector is > null, and this is shared? Am I missing somthing wrt to the copting of any > derived class of Function? > > Johan
I haven't followed this in detail, so I may misunderstand, but if you have a subclass MyFunction of Function, copying it to a Function can't possibly work. How could it? However, Function can make a discrete function from MyFunction, then it's ok. Martin _______________________________________________ DOLFIN-dev mailing list [email protected] http://www.fenics.org/mailman/listinfo/dolfin-dev
