Re: [Boost-users] Help with Visual Studio settings for BoostSerialization

Subject: Re: [Boost-users] Help with Visual Studio settings for BoostSerialization
From: Edward Diener (eldiener_at_[hidden])
Date: 2010-12-04 20:49:51

On 12/4/2010 6:49 PM, Abdullah ARSLAN wrote:
> you seem to be right.
> I was using a header file for class declaration and a cpp file for
> definition, when i moved everything to cpp file,
> It worked.
>
> But what is the problem? My header file contains
>   template<class Archive>
>      void serialize(Archive & ar, const unsigned int version);
>
> and in cpp file
> template<class Archive>
> void g7GameObject::serialize(Archive & ar, const unsigned int version)
> {
> ar & height;
> ar & width;
> ......
> } // my class name is g7GameObject
>
> and with above code i get following error
> error LNK2019: unresolved external symbol "private: void __thiscall
> g7GameObject::serialize....
>
> What am i doing wrong

In the typical template inclusion model, both the template declaration 
and the template definition need to be in a header file so that soure 
using the template can include that header file and get the full 
template code. If you put the definition in a source file it is quite 
likely that code which uses that template never "include"s that source 
file and therefore the template definition is missing when you link.