Question : Unresolved external symbol error

Hi,

I am tryng to complile my project, but i am getting unresolved external symbol errors. On programme entry I have created an application class depending on the outcome of test see code below.

However, both the NAR_app object and the ACE_app object need to be global and visible by all other functions. So, i have declared at the top of all my scripts the following..

extern ACE_manager ACE_app;
NAR_manager NAR_app;

I am getting loads of linking errors like:

Error 2 error LNK2001: unresolved external symbol "class ACE_manager ACE_app" (?ACE_app@@3VACE_manager@@A) Trajectory Scan.obj NARSIM_PARSER

---And i have no real idea what is going on...

Also..how do i ensure that the programme ENTERS in the correct .cpp file?? Other than calling the function 'main'--how does the compiler know?

Many thanks

Simondo

Code Snippet:

         
           
             1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:

           
           
             // THE USER CAN NOT HAVE BOTH CHECKED AT THE SAME TIME. IT IS AN ACE OR NARSIM PARSE. NOT BOTH.
 
	int NAR=0;										// Radio button input for a NARSIM Parse
	int ACE=1;										// RAdio button input for an ACE Parse
 
 
	if (NAR)
	{
		NAR_manager NAR_app;						// Create a NARSIM application object to manage the parse
		NARSIM_PARSE();								// Go and parse NARSIM Files
	}
	if (ACE)
	{
		ACE_manager ACE_app;						// Create an ACE application object to manage the parse
		ACE_PARSE();								// Go and parse ACE files
	}
 
 
return 0;
}

           
         

Open in New Window Select All

Answer : Unresolved external symbol error

>> Hmm, okay what would that look like?

Ok, quick and dirty...

extern ACE_manager * pACE_app; // THis will be NULL until created, it will never be deleted unless you write code to do so or use an auto_ptr

if (ACE)
{
pACE_app = new ACE_manager ACE_app; // Create an ACE application object to manage the parse
ACE_PARSE(); // Go and parse ACE files
}