LNK2019 Errors with Templates

  • Thread starter Thread starter Chris B
  • Start date Start date
C

Chris B

Im trying out VS.NET 2003 by trying to make my own single linked list
library. Im trying to use templates but keep getting LNK2019 errors.
Right now I slimmed down my project to just the main.cpp, linked
list.cpp/h and Node.cpp/h
My error messages:
LibTest error LNK2019: unresolved external symbol "public: __thiscall
CSL::SingleLinkedList<int>::~SingleLinkedList<int>(void)"
(??1?$SingleLinkedList@H@CSL@@QAE@XZ) referenced in function _main

LibTest error LNK2019: unresolved external symbol "public: void
__thiscall CSL::SingleLinkedList<int>::Reverse(void)"
(?Reverse@?$SingleLinkedList@H@CSL@@QAEXXZ) referenced in function
_main


I posted the basics of my code at this link:
http://www.rafb.net/paste/results/OE4JNE25.html
I left out some to save space

I'm looking for any suggestions.
 
Chris said:
I'm looking for any suggestions.
Click to expand...

Have you by chance put the bodies of your template class members in a .CPP
file, like you would an ordinary non-template class? If so, that's your
problem - the bodies have to be visible to the compiler in every translation
unit where the template is used. In practice this usually means that
templates are implemented entirely in the header file.

-cd
 
Carl Daniel said:
Have you by chance put the bodies of your template class members in a .CPP
file, like you would an ordinary non-template class? If so, that's your
problem - the bodies have to be visible to the compiler in every translation
unit where the template is used. In practice this usually means that
templates are implemented entirely in the header file.

-cd
Click to expand...

Thanks! I got it too work with everything in the .h file.
Is there any way to hide the implementation so that if everything is
not in the .h file?
 
Chris said:
Thanks! I got it too work with everything in the .h file.
Is there any way to hide the implementation so that if everything is
not in the .h file?
Click to expand...

No, not really. some people put the implementation in another file
(frequently with the extension .ipp) and then #include that file at the end
of the header, but in the end, that's really not much different from having
the implementation in the header.

The C++ standard provides for another template model through the 'export'
keyword that does allow you to keep your template function bodies out of the
header file. Unfortunately, only one C++ compiler in existence (Comeau C++)
fully supports export. With an export-capable compiler, you still have to
ship your templates as source code if you distribute your code... but it
does get the code out of the header file.

-cd
 
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