🚀 go-pugleaf

Michael McCarty (mikem@eai.com) wrote:
|> I confess I haven't read much of the draft standard and frankly I hope I never
|> have to, but I do have one question that is puzzling me:

|> How exactly is dynamic_cast<T> supposed to be implemented in the compiler?

|> The implementation of this worries me a bit.  I can't really imagine this
|> functionality having a practical implementation (i.e. without breaking a LOT of

|> code).

|> It seems to me that the only way to implement this is to attach a type
|> 'pointer' to every object instantiated, similar to virtual function pointer
|> tables.  If this is so, I strongly disagree with this implementation and, if it

|> came to pass in the standard, would strongly consider migrating back to C
|> because of it.

Dynamic_cast only works on objects with at least one virtual function.
In this case, there is already a `type pointer' attached, at least in
the common implementation.  Or what else would you call the pointer to
the virtual function tables.
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