SoundStream - Pure virtual method called

#include <SFML/Audio.hpp>
#include <SFML/System.hpp>
#include <SFML/Graphics.hpp>
#include <SFML/Network.hpp>
#include <windows.h>
#include <iostream>
#include <ctime>
#include <cstdio>

using namespace sf;

Int16 smp[ 44110 ];

class CustomStream
    : public SoundStream
{
    bool onGetData( Chunk & data )
    {
        data.sampleCount = 44110;
        data.samples = smp;
    }
   
    void onSeek( sf::Time timeOffset )
    {
       
    }
   
public:
    void init()
    {
        initialize( 1, 44100 );
    }
};

int main()
{
   
    CustomStream strim;
    strim.init();
   
    for( int i = 0; i < 44110; i++ )
    {
        smp[ i ] =( rand() % 5000 ) *- 1;
    }
   
    strim.play();
}