对象成员实践一 提示undefined reference
||=== 构建文件: "无目标" in "无项目" (compiler: 未知的) ===| D:\filedemo\imooc_xy.o||In function `main':| D:\filedemo\imooc_xy.cpp|16|undefined reference to `Line::Line()'| D:\filedemo\imooc_xy.cpp|17|undefined reference to `Line::~Line()'| ||error: ld returned 1 exit status| ||=== Build 失败: 3 error(s), 0 warning(s) (0 minute(s), 0 second(s)) ===|
