#include <iostream>
#include <sstream>

class Utl
{
public:

    // singleton accessor
    static Utl& GetInstance();

    virtual std::string GetHello( bool full ) = 0;
};

class UtlImpl : public Utl
{
public:
    UtlImpl() {}

    virtual std::string GetHello( bool full )
    {
        return (full)?"full":"partial";
    }
};

Utl& Utl::GetInstance()
{
    static UtlImpl instance;
    return instance;
}

int main( int argc, char* argv[] )
{
    std::cout << Utl::GetInstance().GetHello(true) << std::endl;
    std::cout << Utl::GetInstance().GetHello(false) << std::endl;
    return 0;
}