undefined reference to Struct

Contributor
26Oct2010,19:16   #1
heidik's Avatar
Code:
breachmonitor.cpp:(.text+0x17ce): undefined reference to `BreachMonitor::Breach::Breach()'
Can anyone please tell me what does it mean? I have created a struct and then declared its variable like

Code:
Breach wb;
and it isnt compiling. The structure has default constructor (no arguments) and another one for initialization. It has also got two methods.

Code:
bool operator==(const Breach& p) const
bool operator<(const Breach& p) const