Can you help? The following code:
class MT
{
public:
static int ms_number;
};
int MT::ms_number;
yields:
Error 8 error LNK2005: "public: static int MT::ms_number"
(?ms_number@MT@@2HA) already defined in ProjName.obj
Why?
views:
83answers:
2
+11
A:
You need to move this line:
int MT::ms_number;
out of your .h file and into a single .cpp file.
R Samuel Klatchko
2010-06-20 15:48:58
great! it works! thanks!but why? what's the problem of it to be in the .h?
Hellfrost
2010-06-20 16:03:41
@Hellfrost: You're only allowed to define it once. If it's in a header, then it will end up being defined in every source file that includes the header.
Mike Seymour
2010-06-20 16:24:21
A:
The static needs to be defined as extern, in addition to R Samuel Klatchko's answer.
DeadMG
2010-06-20 15:52:51
No it doesn't. That's only needed for objects at namespace scope, not static class members.
Mike Seymour
2010-06-20 16:05:35