Question

I heard a saying that c++ programmers should avoid memset,

class ArrInit {
    //! int a[1024] = { 0 };
    int a[1024];
public:
    ArrInit() {  memset(a, 0, 1024 * sizeof(int)); }
};

so considering the code above,if you do not use memset,how could you make a[1..1024] filled with zero?Whats wrong with memset in C++?

thanks.

Answer 1

The issue is not so much using memset() on the built-in types, it is using them on class (aka non-POD) types. Doing so will almost always do the wrong thing and frequently do the fatal thing – it may, for example, trample over a virtual function table pointer.