Re: Need help on this error
Neo wrote:
class A {
virtual void func1()=0;
....
}
class B {
virtual void func2()=0;
...
}
class C: public A, public B {
virtual void func1()=0;
virtual void func2()=0;
...
}
where below class C is "bidir_chan"
Hmmm, obviously the above doesn't compile.
bidir_chan.o:bidir_chan.cpp:(.rdata$_ZTV10bidir_chan[vtable for
bidir_chan]+0x20): undefined reference to `bidir_chan::~bidir_chan()'
It's missing a reference to the destructor of bidir_chan. Either it was
declared and not implemented or the objectfile is not part of the link.
If you want further advise, you will need to factor out a minimal testcase.
The problem with your description is the same that someone had a few days
ago here, namely "kiran" in a thread called "segmentation fault".
bidir_chan.o:bidir_chan.cpp:(.rdata$_ZTV10bidir_chan[vtable for
bidir_chan]+0x54): undefined reference to `non-virtual thunk to
bidir_chan::~bidir_chan()'
collect2: ld returned 1 exit status
what is this THUNK thing? I am using cygwin g++ ver 3.4.4-2
It's an internal implementation detail of how g++ models virtual functions.
It is normally nothing you need to worry about, just writing correct C++
should do the job.
Uli
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