Re: Casting void*, comparing void*
On 05.02.2015 15:08, Martin Bonner wrote:
On Wednesday, 4 February 2015 15:00:12 UTC, Jens M?ller wrote:
Given the following example code:
class A {
public: A() {}
};
class B {
public; B() {}
};
A* a = new A();
B* b = new B();
void *aVoid = a;
void *bVoid = b;
bool compareVoid = (aVoid == bVoid); // (1) false?
B* aCastedToB = static_cast<B*> aVoid;
bool compareB = (aCastedToB == b); // (2) false or unspecified?
There's a third alternative: "Undefined". I strongly suspect that
either compareB or aCastedToB is undefined behaviour.
I agree that the statci_cast looks like UB.
See also:
"Is comparing two void pointers to different objects defined in C++?"
http://stackoverflow.com/questions/8225501/is-comparing-two-void-pointers-to-different-objects-defined-in-c
cheers,
Martin
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