11 Dec
2013
11 Dec
'13
1:17 a.m.
You are referring to a function in the source code which is not linked into the binary. Specifically:
echo _ZNK4ldu23lcfEv | c++filt ldu2::lcf() const
Which is the function I presume you've written. For whatever reason the code for that function is not present in the object files the linker knows about. Hope that helps.