Pointer questions - GNU c++ on a unix platform

[emp]

I have 3 structures in my header file
struct{
int a;
int b;
} header;

struct{
int c;
int d;
} trailer;

struct{
header hdr;
trailer trl;
} msg_struct;

I declare an instance in my code

msg_struct new_msg;

After I populate new_msg, I then want to pass a pointer to new message to a special printFunc() I have written.

My call to the function
printFunc(&new_ msg);

HERE's My first problem -----
What should the function prototype look like in my header file for printFunc()
I have
printFunc(int *)

I get compiler error saying cannot convert int** to int* for argument 1.....

HERE's My second problem -----

In printFunc(), to cout the contents of new_msg, should the line read
std::cout<< new_msg->header.a << std::endl;
std::cout<< new_msg->header.b << std::endl;
etc........

This gives compiler "error expected unqualified-id before '.' token" which I assume means that it doesn't understand what the "new_msg->" is

Any help would be appreciated.

Thanks

emp1953

[mschenkelberg]

Change your printFunc( int * ) function to printFunc ( msg_struct * new_msg )

that should solve the problems

Max

[emp]

I assume you suggest making the change both in the function declaration in the header file and in the function itself?

When I do that I get a compiler error that says something very similar to original error.

cannot convert msg_struct** to msg_struct*
and the unqualified-id error has not changed

[mschenkelberg]

can you post all of the source?

[emp]

What I'm working is sensitive so I'm posting a simplified version
Here's the header file

printFunc.h

struct{
int a;
int b;
} header;

struct{
int c;
ind d;
} trailer;

struct{

header hdr;

trailer trl;

} msg_struct;





void decodeOutput(ms g_type_enum, msg_struct *);
void printFunc(msg_s truct *);



############### ############### ############### ############### ############### #######





Here's the code.cpp

#include "printFunc. h"

void decodeOutput(ms g_type_enum typeIn, msg_struct *msgIn){
{
switch(typeIn)

{

case 0: printFunc(&msgI n);

default: break;

}

}
void printFunc(msg_s truct *msgIn)

{

std::cout<< msgin->hdr.a << std::endl;

std::cout<< msgin->hdr.b << std::endl;

std::cout<< msgin->trl.c << std::endl;

std::cout<< msgin->trl.d << std::endl;

}

############### ############### ############### ############### ############### ########


Compiler errors


error: cannot convert int** to int* for argument 1 (""this refers to the case 0 call to printFunc in the switch")

error: expected unqualified-id before '.' token (""This refers to the couts, referring to the msgIn->")

[emp]

Sorry, a correction to my most recent code pose

error: cannot convert msg_struct** to msg_struct* for argument 1 (""this refers to the case 0 call to printFunc in the switch")

error: expected unqualified-id before '.' token (""This refers to the couts, referring to the msgIn->")

[mschenkelberg]

It is because you already passed the msg_struct as a pointer to the decode function therefore you do not need to & operator when passing the msg_struct to the printFunc. It should look like this:

case 0:
printFunc( msgln );


Max

[emp]

It is because you already passed the msg_struct as a pointer to the decode function therefore you do not need to & operator when passing the msg_struct to the printFunc. It should look like this:

case 0:
printFunc( msgln );


Max

############### ############### ############### #######

Thank You Max, that got rid of the can't convert msg_struct** to msg_struct* error

I still have the compiler error
expected unqualified-id before '.' token

Which I assume is the msgIn-> in my cout....


emp1953

[mschenkelberg]

you typed msgin -> ... when it should be msgln

capital vs lowercase

Max

[emp]

you typed msgin -> ... when it should be msgln

capital vs lowercase

Max

Duh! My brain is on caffeine overdose. I hope I don't have to bother you guys with this any more

Thanks again