Why won't the last two member functions compile?

Also when this does compile, will it always work correctly
across platforms?

#include <stdio.h>
#include <string.h>
#include <vector>
#define uint8 unsigned char
#define uint16 unsigned short
#define uint32 unsigned int

std::vector<uint32> DataBlock;

struct Test {
  uint32 Var1;
  uint16 Var2;
  uint8 Var3;
  uint8 Var4;
  uint8 Var5;
  std::vector<uint8> Var6;
  Test();
  void Out();
  void Serialize(std::vector<uint32> DataBlock, uint32&
Offset){ memcpy(&DataBlock[0], this, 9); };
  void DeSerialize(std::vector<uint32> DataBlock, uint32&
Offset){ memcpy(this, &DataBlock[0], 9); };
};

Test::Test() {
  Var1 = 1;
  Var2 = 2;
  Var3 = 3;
  Var4 = 4;
  Var5 = 5;
  for (int N = 1; N <= 10; N++)
    Var6.push_back(N);
}

void Test::Out() {
  printf("%d %d %d %d %d---", Var1, Var2, Var3, Var4, Var5);
  for (int N = 0; N < Var6.size(); N++)
    printf("%d-", Var6[N]);
  printf("\n");
}

Test T1;
Test T2;

int main() {
  DataBlock.resize(4);
  T1.Serialize(DataBlock, 0);
  T1.Out();
  T1.DeSerialize(DataBlock, 0);
  T1.Out();
  return 0;
}