Re: Casting to a derived class
PGK wrote:
Is it safe to cast from a base class pointer to a derived one? My
guess is that it's not, though may go unnoticed if the derived class
has no member variables.
Yep, "undefined behaviour" has many faces.
On the other hand, when I compile the code below I get no warnings.
Surely if this is less than savoury, the compiler should tell?
You are explicitly silencing the compiler with the cast. It could even be
totally unrelated types, you are effectively telling the compiler "Shut up,
I know what I'm doing!".
int main(int argc, char *argv[]) {
der *pd = (der *)new base();
The correct cast is static_cast, but it requires that you know by some means
that the source pointer points to the actual derived type, which this one
doesn't.
pd->d = 123;
This of course is straight out.
Uli
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