LNK2019 errors

"unresolved external symbol"

First of all it can help to turn off Use Precompiled Headers.. project properties: C/C++->Precompiled headers.

I have read that it is caused by functions being declared but not defined. The errors show up when you try to use these functions.

Now here's the really moronic reason for the error:

REMEMBER TO ADD THE CLASS SCOPE TO YOUR FUNCTION DEFINITIONS

e.g.

Class1.h
class A {
dosomething();
}

Class1.cpp
A::dosomething() {}

NOT:

dosomething() {}


HOWEVER, there are still more reasons for the occurrence of this error.. hopefully they will appear here in the future..