📜  mingw32 bin ld.exe: C:\Users\mfrom\AppData\Local\Temp\ccSKcRks.o:PizzaPi.cpp:(.text$_ZN5PizzaC2Ev[__ZN5PizzaC2Ev]+0xa): undefined reference to `vtable for Pizza' collect2.exe : 错误: ld 返回 1 个退出状态 - C++ 代码示例

virtual void process() = 0;