The static_cast operator is used to convert with a compile time check, but not a runtime check, so this means that the pointers must be related. The void* pointer can be converted to any pointer, so the following compiles and makes sense:
int *pi = static_cast<int*>(malloc(sizeof(int))); *pi = 42; cout << *pi << endl; free(pi);
The C malloc function returns a void* pointer so you have to convert it to be able to use the memory. (Of course, the C++ new operator removes the need for such casting.) The built-in types are not "related" enough for static_cast to convert between pointer types, so you cannot use static_cast to convert an int* pointer to a char* pointer, even though int and char are both integer ...
