binding to C++

[drug via Digitalmars-d-learn]

Trying to bind to cpp code I stop at some moment having undefined 
reference to some cpp function. But objdump -Ct cpplibrary.so shows me 
that this cpp function exists in the library. linker message about cpp 
function is _identical_ to objdump message so I don't know where is the 
difference. For example linker says:
`undefined reference to 
`Namespace::StructName::method_name(Namespace::Otherstruct const*)`
And ojbdump called by command:
```
objdump -Ct libLibrary.so | method_name
```
shows the following:
```
0000000000026ed0  w    F .text  0000000000000025 
Namespace::StructName::method_name(Namespace::Otherstruct const*)
```
That is two outputs are identical.
Could someone help what to do to investigate the problem?
Thanks in advance