this is my easy code to learn vitual class，this code can be complied by clion 。
class BaseA{
public:
BaseA(){};
~BaseA(){};
int a;
virtual void fuc()=0;
};
class DrivedA:public BaseA{
public:
DrivedA(){};
~DrivedA(){};
int b;
void fuc() override{
b=2;
};
};
int main() {
DrivedA drivedA;
drivedA.fuc();
return 0;
}
this is makeLists：
cmake_minimum_required(VERSION 3.21)
project(learn_gcc_and_classvitrualtable)
set(CMAKE_CXX_STANDARD 20)
add_executable(learn_gcc_and_classvitrualtable main.cpp)
but when i use gcc alone to compile it，it does not work with these error。 Is there anything wrong in my code or i use gcc in a wrong way... Could you please help me?
[myk@MYK learn_gcc_and_classvitrualtable]$ gcc main.cpp
/usr/bin/ld: /tmp/ccY9AVjz.o:(.data.rel.ro._ZTI7DrivedA[_ZTI7DrivedA]+0x0): undefined reference to `vtable for __cxxabiv1::__si_class_type_info'
/usr/bin/ld: /tmp/ccY9AVjz.o:(.data.rel.ro._ZTI5BaseA[_ZTI5BaseA]+0x0): undefined reference to `vtable for __cxxabiv1::__class_type_info'
collect2: error: ld returned 1 exit status
