Consider the following code:
=== bug.cpp ===
struct Test {
 static const int number=5;
 int test(const int n);
};

int Test::test(const int n)
{
 int max = number > n ? number : n;
 return max;
}

int main()
{
 Test t;
 t.test(6);
 return 0;
}
============
I get the following linker error:
/tmp/ccWCtyqx.o(.text+0x18): In function `Test::test(int)':
: undefined reference to `Test::number'
collect2: ld returned 1 exit status

I have tested g++ 3.3.5, 4.0.2, and 4.1.0. With g++ 4.* and -O2 the error disappears. Also if one replaces the ? : by an if statement, the error disappears. Of course, an additional "extern const int Test::number;" also solves the problem.

Environment: i386-linux (Debian GNU/Linux)
Releases: 3.3.5, 4.0.2, 4.1.0
How-To-Repeat: g++ -o bug bug.cpp

Best regards,
Elmar