base.cpp

#include "base.h"

using namespace std;

base::base()
{
    a = 3;
    b = 2;
}

int base::add(int x, int y)
{
    return x + y;
}

template<class Archive>
void base::save(Archive & archive) const
{     
    archive(a, b); 
}

template<class Archive>
void base::load(Archive & archive) 
{     
    archive(a, b); 
}

base.h

#define CEREAL_SAVE_FUNCTION_NAME cereal_save
#define CEREAL_LOAD_FUNCTION_NAME cereal_load

#ifndef base_h_
#define base_h_

using namespace std;
class base
{
public:
    int a, b;
    base();
    
    int add(int x, int y);
    
    template<class Archive>
    void save(Archive & archive) const;
    
    
    template<class Archive>
    void load(Archive & archive);
};

#endif 

#undef CEREAL_SAVE_FUNCTION_NAME
#undef CEREAL_LOAD_FUNCTION_NAME

derived.h

#include "base.h"

using namespace std;
class derived : public base
{
public:
    int c, d;
    derived() : base()
    {
        c = 0;
        d = -1;
    }
    
};

error msg

Makefile

Mac148934:test2 zora$ g++ -c -std=c++11 base.cpp
Mac148934:test2 zora$ g++ -c -std=c++11 test.cpp
Mac148934:test2 zora$ g++ -std=c++11 base.o test.o -o test

Undefined symbols for architecture x86_64:
  "void base::serialize<cereal::JSONOutputArchive>(cereal::JSONOutputArchive&) const", referenced from:
      decltype(fp0.serialize(fp)) cereal::access::member_serialize<cereal::JSONOutputArchive, derived>(cereal::JSONOutputArchive&, derived&) in test.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

test.cpp

#include "cereal/archives/json.hpp"
#include <fstream>
#include "derived.h"

using namespace std;

int main()
{
    derived d;
        
    {
        std::ofstream os("cereatltest_save.cereal");
        cereal::JSONOutputArchive archive(os);
        archive(d);
    }
    
    return 0;
}