再次遇到 undefined reference to `vtable for XXXX'

 
之前遇到过一次，这次又遇到，又想不起来了，搜了一通还是找到了上次搜索的结果，特此记录备忘：

http://bytes.com/topic/c/answers/161894-undefined-reference-vtable

===================

That is the most obscure error message the gcc produces, but the reason

is usually simple:

The compiler has to put the vtable into an object file. It puts it into

the object file where the definition of the first non-inline member

function is. If it is missing, you get this rather unhelpful linker

error. Please check the existence of the definitions of your member
functions.

Gabriel

===================

 

原因就是：有成员函数未定义...