What is undefined reference?
An “Undefined Reference” error occurs when we have a reference to object name (class, function, variable, etc.) in our program and the linker cannot find its definition when it tries to search for it in all the linked object files and libraries.
What is undefined reference to Vtable?
When linker says “undefined reference to vtable for IBase” it basically means that Derived has vtable reference to IBase but it can’t find any compiled object code of IBase to look up to. So the bottom line is that class IBase has declarations without implementations.
What is Vtable C++?
To implement virtual functions, C++ uses a special form of late binding known as the virtual table. The virtual table is a lookup table of functions used to resolve function calls in a dynamic/late binding manner. A virtual table contains one entry for each virtual function that can be called by objects of the class.
How to fix undefined reference to vtable Stack Overflow?
It just gave me the vtable error message, and implementing the (empty) destructor solved the problem. Thus, the corrected class file looks like this: A couple of people have already pointed out the solution to the problem you’ve seen. I’ll add something rather different. You only need header guards in your headers.
What does undefined reference to vtable for iBase mean?
When linker says “undefined reference to vtable for IBase” it basically means that Derived has vtable reference to IBase but it can’t find any compiled object code of IBase to look up to. So the bottom line is that class IBase has declarations without implementations.
How to deal with undefined reference in Qt?
Unless you place them into .pro file under HEADERS section – you will get this “undefined reference” A quick option to solve the problem is to remove the Q_OBJECT macro, this will allow you to compile and test your application, but, not a right choice, if you intend to work every day with QT on CB must configure your environment.
Why is there no vtable in Stack Overflow?
Absence of a vtable is usually a symptom of failing to include the output of moc in the linker arguments. Make sure that you ran moc on your header, and that you linked the result.
