typeinfo 未定义的引用
https://cloud.tencent.com/developer/ask/29853/answer/38024
编译链接错误：对‘vtable for xxxx’未定义的引用
https://www.wandouip.com/t5i109220/
未定义的引用typeinfo for class'(undefined reference totypeinfo for class’)
http://www.it1352.com/488500.html
