Hi Robert, Robert Dailey skrev:
On Windows, I plan to create a ptr_vector in a separate DLL and propagate it to the executable for ownership (Factory-style). The executable will be responsible for the lifetime of this ptr_vector, and will eventually result in "delete" being called on each element in the ptr_vector. However, this 'delete' will be from the executable's memory manager, when the memory was originally allocated in the shared library's memory manager, causing serious issues.
It would be ideal to specify a delete_clone class that ptr_vector would use (via ADL) and would force those objects in the ptr_vector to use the 'delete' call from the DLL's memory manager, and not the executable's.
I don't see that this is going to be possible, or at least able to be done easily. Since the delete_clone's operator will have to be implemented in a CPP file, so it will be included into the shared library. This also implies that I'll have to import the delete_clone's interface, since this DLL will be loaded dynamically with LoadLibrary() in Windows. I just don't see this happening.
Now, if ptr_vector had a function like so:
ptr_vector::set_deleter()
I could give it a pointer to a global function in my DLL, and the deleter becomes fully transparent to my executable. It just has to keep the ptr_vector around and let it fall out of scope and the deleter from the DLL will be used to delete each object in the ptr_vector. However, it isn't this simple and I need advice on how I can make this work.
Well, we need to make the clone_allocator stateful, which is currently not supported. I always was lacking a good argument, so let's work on the design of this on the dev list. -Thorsten