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I'm reading some code in the Ogre3D implementation and I can't understand what a void * type variable means. What does a pointer to void mean in C++?
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A void pointer is a pointer that can point to any type of object, but does not know what type of object it points to. A void pointer must be explicitly cast into another type of pointer to perform indirection. A null pointer is a pointer that does not point to an address. A void pointer can be a null pointer.
Example of pointer in Cint a=5; int* point = &a; // pointer variable point is pointing to the address of the integer variable a! int a=5; int* point = &a; // pointer variable point is pointing to the address of the integer variable a!
Not only is it OK to free() a void * value, by definition, all free() ever sees is a void * , so technically, everything freed in C is void * :-) @Daniel - If you ask me, it should be struct foo *p = malloc(sizeof *p)); but what do I know?
A pointer to void, void* can point to any object:
int a = 5;
void *p = &a;
double b = 3.14;
p = &b;
You can't dereference, increment or decrement that pointer, because you don't know what type you point to. The idea is that void* can be used for functions like memcpy that just copy memory blocks around, and don't care about the type that they copy.
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It's just a generic pointer, used to pass data when you don't know the type. You have to cast it to the correct type in order to use it.
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