This gist represents the provider module, as described in my post titled "Write an Interface between your program and a Shared Object"

main.cpp

// Test for the shared object

#include "provider.hpp"
#include <iostream>

int main()
{
    Provider p;
    std::string surname("Wilkes");
    std::cout << "Wilkes, " << p.GetResource(surname) << '\n';
    return 0;
}

Makefile

provider_name := provider

.PHONY: all
all: main

%.o: %.cpp
	g++ -Wall -Werror -fPIC -c $<

.PHONY: $(provider_name)
$(provider_name): provider.o resource.o
	g++ -shared -Wl,-soname,lib$@.so.1 -o lib$@.so.1.0 $^
	ln -sf lib$@.so.1.0 lib$@.so.1 
	ln -sf lib$@.so.1 lib$@.so

main.o: main.cpp
	g++ -g -Wall -Werror -c $<

main: main.o $(provider_name) 
	g++ $< -L. -l$(provider_name) -o $@ 

clean:
	rm -f *.o lib$(provider_name).so* main

love:
	@echo "...not war!"

provider.cpp

#include "provider.hpp"
#include "resource.hpp"
#include <iostream>

Provider::Provider() : r_(new Resource())
{
    std::clog << "Provider::Provider()\n";
}

std::string Provider::GetResource(const std::string& name)
{
    std::clog << "Provider::GetResource()\n";
    return r_->GetName(name);
}

provider.hpp

#ifndef PROVIDER_HPP
#define PROVIDER_HPP

#include <string>

class Resource;

class Provider {
    Resource* r_;

public:    
    Provider();
    std::string GetResource(const std::string& name);
};

#endif // PROVIDER_HPP

resource.cpp

#include "resource.hpp"
#include <map>
#include <string>
#include <exception>
#include <stdexcept>
#include <iostream>

using std::map;
using std::string;
using std::out_of_range;
using std::exception;
using std::cerr;
using std::clog;

Resource::Resource()
{
    clog << "Resource::Resource()\n";
    dict_["Lovelace"] = "Ada";
    dict_["Wilkes"] = "Mary Allen";
    dict_["Liskov"] = "Barbara";
}

std::string Resource::GetName(const std::string& surname)
{
    clog << "Resource::GetName(surname=" << surname << ")\n";
    string res;
    try {
        res = dict_.at(surname);
    } catch (const out_of_range& oor) {
        cerr << "Element not in map:\n" << surname << '\n';
        throw;
    } catch (const exception& ex) {
        cerr << "Unknown exception!\n" << ex.what();
        throw;
    }
    clog << "res = [" << res << "]\n";
    return res;
}

resource.hpp

#ifndef RESOURCE_HPP
#define RESOURCE_HPP

#include <map>
#include <string>

using std::map;
using std::string;

class Resource {
    map<string, string> dict_;

public:    
    Resource();
    std::string GetName(const std::string& surname);
};

#endif // RESOURCE_HPP