typedef jr_src_hash_slot struct jr_src_hash_slot;

typedef struct jr_src_hash_slot jr_src_hash_slot;

#endif _jr_src_hash_h

 	Thanks dmail for your reply, but multiple types in one declaration error is what really breaking the compilation, isn't it?!

i tried to google it, but no solution is working with me

#ifndef _jr_src_hash_h
#define _jr_src_hash_h

#include <odmrp/defs.h>

//forward declare the struct
struct jr_src_hash_slot;

struct jr_src_hash_slot{
nsaddr_t src;
int seqno;
nsaddr_t prev_hop; /* why do we need this?? */
int hop_count;
/*--struct--*/ jr_src_hash_slot *next;
};

/*--no need for this here its C++-- typedef jr_src_hash_slot struct jr_src_hash_slot;*/

class JRSrcTable {
private:
/*struct --no need for this here its C++*/ 
jr_src_hash_slot *hash_table[OD_JR_SRC_HASH_SIZE];
public:
JRSrcTable();
~JRSrcTable();

int lookup(nsaddr_t src_addr, nsaddr_t prev_hop, int seqno);
int enterInTable(nsaddr_t src_addr, nsaddr_t prev_hop, int seqno);
int removeFromTable(nsaddr_t src_addr);

void printTable();
};

#endif //_jr_src_hash_h