The use case is if you have a wrapper class:
class Base {
void *Ptr;
public:
Base() : Ptr(0) { }
operator bool() const { return Ptr; }
.....
}
and sub-wrappers that have exactly the same size:
class Sub : public Base {
public:
....
static bool classof(const Base*);
}
and in the code you would do:
void f(Base b) {
Sub sub = dyn_cast<Sub>(b);
if (sub) {
....
}
}
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78424 91177308-0d34-0410-b5e6-96231b3b80d8
8b6d86df06