Struct NonStandard variable length in C ++ 11?

Question

Possible duplicate:
Technically, the behavior is undefined "struct hack>

I checked if zero-length arrays are allowed in C ++ 11. It turned out that this is not the case. From8.3.4 Arrays [dcl.array]

If the constant expression (5.19) is present, it must be an integral constant expression and its value must be greater than zero.

Since I cannot use arrays of zero length Can I use structures of variable length, being standard / chucked? For example, I would like to do something like below. How to make it well defined and standard when the buffer MAY BE EMPTY.

-edit- related: Array of zero length

struct MyStruct {
    uint size;
    int32 buf[0];//<-- NonStandard!
};
...
auto len=GetLength();
auto ptr=GetPtr();
auto bytelen=len*sizeof(int32);
var p = reinterpret_cast<MyStruct*>(malloc(bytelen))
p->size=len
memcpy(p->buf, ptr, bytelen)
return p;

Answer 1

++, C. ++, , , . :

#include <cstring>

template <typename STRUCT, typename TYPE> class flex_struct {
public:
  TYPE *tail()
  {
    return (TYPE *) ((char *) this + padded_size());
  }

  // substitute malloc/free here for new[]/delete[] if you want
  void *operator new(size_t size, size_t tail)
  {
    size_t total = padded_size() + sizeof (TYPE) * tail;
    return new char[total];
  }

  void operator delete(void *mem)
  {
    delete [] (char *) mem;
  }
private:
  static size_t padded_size() {
    size_t padded = sizeof (flex_struct<STRUCT, TYPE>);
    if(padded % alignof(TYPE) != 0) {
         padded = padded & ~(alignof(TYPE)-1) + alignof(TYPE);
    }
    return padded;
  }
};

struct mystruct : public flex_struct<mystruct, char> {
  int regular_member;
};

int main()
{
  mystruct *s = new (100) mystruct; // mystruct with 100 chars extra
  char *ptr = s->tail();            // get pointer to those 100 chars
  memset(ptr, 0, 100);              // fill them
  delete s;                         // blow off struct and 100 chars
}

Answer 2

, .

std::vector.

^{* , ++ , C . , , , .}

Answer 3

. :

struct MyStruct {
    uint size;
    int32 buf[1];
};