extern "C"
{
 #include <sys/types.h>
 #include <sys/ipc.h>
 #include <sys/shm.h>
}
template <class InputClass>
class SharedMemory
{
 private:
  key_t key;
  int shmid;
  InputClass *data;
  int SHM_SIZE;
  string fileName;
 
  void initialize()
  {
   if ((key = ftok(fileName.c_str(), 'R')) == -1) 
   {
	   throw DHException( "*** Could not connect to shared memory file [" + fileName + "] Check that the file exists...***" );
 }
 
  /* connect to (and possibly create) the segment: */
	  if ((shmid = shmget(key, SHM_SIZE, 0644 | IPC_CREAT)) == -1)
	  {
		throw DHException( "*** Could not use shared memory file: [" + fileName + "] Check that the allocated size is OK..***");
	  }
 
	  data = (InputClass *) shmat(shmid, 0, 0);
	  if (data == (InputClass *)(-1)) 
	  {
	   throw DHException ( "*** Could not connect to shared memory file:(error 3):" + fileName);
	  }
  }
 
  public:
  SharedMemory( string file )
  {
   SHM_SIZE=sizeof(InputClass);
   fileName = file;
   initialize();
 
  }
 
  SharedMemory( int size, string file )
  {
   SHM_SIZE=size;
   fileName = file;
   initialize();
  }
 
 
  void writeToSharedMemory( InputClass ic )
  {
   *data = ic;
  }
 
  InputClass getFromSharedMemory( )
  {
   return *data;
  }
 
  ~SharedMemory()
  {
 
   if (shmdt((char *)data) == -1) 
   {
	throw DHException ( "Could not disconnect from shared memory file:" + fileName );
	}
  }
 
  int getMemorySize() { return SHM_SIZE; }

 SharedMemory<Date> shm(1000, "DANTEST" );
 
 while ( true )
 {
 
  Date a;
  shm.writeToSharedMemory(a);
  screenLog<<"Just Placed:"<<a<<endl;
 
  sleep( 1 );
 
 }

#include <iostream>
#include <string>
#include <cstddef>

void showobject(const void *object, std::size_t size)
{
   const unsigned char *byte = static_cast<const unsigned char *>(object);
   for (size_t i = 0; i < size; ++i)
   {
      std::cout << std::hex << static_cast<int>(byte[i]);
   }
   std::cout << std::endl;
}

int main()
{
   std::string text("hello world");
   std::cout << text << " : ";
   showobject(static_cast<const void *>(&text), sizeof text);
   std::cout << text.c_str() << " : ";
   showobject(static_cast<const void *>(text.c_str()), text.size());
   std::cout << static_cast<const void *>(&text[0]) << std::endl;
   return 0;
}

/* my output
hello world : 4454201000143b7b01000
hello world : 68656c6c6f20776f726c64
007B3B14
007B3B14
*/

class string_proxy {
  std::string _str;
  char *_mem;
public:
  std::string_proxy(char *addr): _mem(addr) {}
  std::string& get() { _str.assign(_mem); }
  void serialize()
  {
    memcpy(_mem, _str.c_str(), _str.size() + 1);
  }
};