C / C++ / MFC

struct foo      
{               // default (align=8)      pack(1)
  char   c;     // & = this+0             & = this + 0
                // (3 pad bytes)          (no pad bytes)   
  int    count; // & = this+4             & = this + 1
};

struct {
  char a;
  char b;    // byte - no padding needed
  __pad[2];  // pad the int to a multiple of 4
  int x;
};

struct {
  char a;
  char b;    
  __pad[6];  // pad the double (8 byte) to a multiple of 8
  double x;
};

struct {
  double x;
  char a;
  char b;    
  __pad[6];   // struct contains an 8 byte member, so pad size to n*8 bytes
};

struct {
  int x;
  int y;
  char a;
  char b;    
  __pad[2];   // biggest memebr struct contains is 4 byte ==> pad size to n*4 bytes
};

struct foo {
  int x, y; char a, b;
};
struct bar {
  double x; char a, b;
};

void main()
{
  cout << "sizeof(foo) = " << sizeof(foo) << endl;
  cout << "sizeof(bar) = " << sizeof(bar) << endl;
}

char *HexDisplayValue( char *buffer, void *value, size_t bytecount )
{
    char *pbuf = buffer;
    BYTE *chval = (BYTE *)value;
    for( size_t index = 0; index < bytecount; ++index, ++chval )
        pbuf += sprintf( pbuf, "%02X", *chval );
    return buffer;
}

char *HexDisplayValue( char *buffer, void *value, size_t bytecount )
{
    char *pbuf = buffer;
    BYTE *chval = (BYTE *)value;
    for( size_t index = 0; index < bytecount; ++index, ++chval )
        pbuf += sprintf( pbuf, "%02X", (unsigned int)(*chval) );
    return buffer;
}

AfxGetApp()->WriteProfileInt(_T("MyRegistryKey"), _T("MyRegistryValue"), m_MyIntValue)