Re: [Libmesh-devel] Casting issues

2009-02-09 Thread Derek Gaston
On Feb 9, 2009, at 1:43 PM, Roy Stogner wrote: > Apparently the compiler can't figure out where to find a vtable > pointer unless it at least knows what the root base class is you're > pointing to, and it can't figure out how to do a proper cast (at least > in the context of multiple inheritance)

Re: [Libmesh-devel] Casting issues

2009-02-09 Thread Roy Stogner
On Mon, 9 Feb 2009, Derek Gaston wrote: > Why can't you cast a void pointer to a class pointer dynamically? > Seems odd to me... so I'm probably doing something wrong. Apparently the compiler can't figure out where to find a vtable pointer unless it at least knows what the root base class is you

[Libmesh-devel] Casting issues

2009-02-09 Thread Derek Gaston
To revisit the discussion on casting last week... I just ran across this issue: error: cannot dynamic_cast ‘oldvar’ (of type ‘void*’) to type ‘class Preconditioner*’ (source is not a pointer to class) The offending code is: PetscErrorCode __libmesh_petsc_preconditioner_setup (void * ctx)