Simple game of life

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <unistd.h>
class GameOfLife{
    private:
        int x_size;
        int y_size;
        std::vector<int> field;
    public:
        GameOfLife(int x = 50, int y = 80);
        void print();
        void set(int x, int y);
        int proxima(int x, int y);
        void evolve();

};

void GameOfLife::print(){
    for (int i = 0; i < y_size+2; ++i)
        std::cout<<"=";
    std::cout<<std::endl;
    std::string buf;
    for (int i = 0; i < x_size; ++i){
            std::cout<<"|";
        for (int j = 0; j < y_size; ++j){
            if(field[i*y_size+j] != 0){
                buf = "#";
            }
            else
                buf = " ";
            std::cout<<buf;
        }
    std::cout<<"|"<<std::endl;
    }
    for (int i = 0; i < y_size+2; ++i)
        std::cout<<"=";
    std::cout<<std::endl;
    usleep(80000);
}

void GameOfLife::set(int x, int y){
    field[x*y_size+y] = 1;
}

int GameOfLife::proxima(int x, int y){
    int sum = 0;
    if (field[((x+1+x_size)%x_size)*y_size+(y+y_size)%y_size] == 1)
        sum+=1;
    if (field[((x+1+x_size)%x_size)*y_size+(y+1+y_size)%y_size] == 1)
        sum+=1;
    if (field[((x+x_size)%x_size)*y_size+(y+1+y_size)%y_size] == 1)
        sum+=1;
    if (field[((x-1+x_size)%x_size)*y_size+(y+1+y_size)%y_size] == 1)
        sum+=1;
    if (field[((x-1+x_size)%x_size)*y_size+(y+y_size)%y_size] == 1)
        sum+=1;
    if (field[((x-1+x_size)%x_size)*y_size+(y-1+y_size)%y_size] == 1)
        sum+=1;
    if (field[((x+x_size)%x_size)*y_size+(y-1+y_size)%y_size] == 1)
        sum+=1;
    if (field[((x+1+x_size)%x_size)*y_size+(y-1+y_size)%y_size] == 1)
        sum+=1;
    return sum;
}

void GameOfLife::evolve(){
    std::vector<int> next = field;
    std::copy(field.begin(), field.end(), next.begin());
    for (int i = 0; i < x_size; ++i){
        for (int j = 0; j < y_size; ++j){
            if (field[i*y_size+j] == 0)
                if (GameOfLife::proxima(i,j) == 3)
                    next[i*y_size+j] = 1;
            if (field[i*y_size+j] == 1)
                if (GameOfLife::proxima(i,j) <= 1 ||  GameOfLife::proxima(i,j) >= 4)
                    next[i*y_size+j] = 0;
        }
    }
    std::copy(next.begin(), next.end(), field.begin());
    GameOfLife::print();
}

GameOfLife::GameOfLife(int x, int y) : x_size(x), y_size(y), field(x_size*y_size,0){
        x_size = x;
        y_size = y;
        std::vector<int> field(x_size*y_size);
}
int main(int argc, char* argv[]){
    GameOfLife GOL(60,100);

    GOL.set(30,2);
    GOL.set(30,3);
    GOL.set(31,2);
    GOL.set(31,3);
    GOL.set(30,12);
    GOL.set(31,12);
    GOL.set(32,12);
    GOL.set(29,13);
    GOL.set(33,13);
    GOL.set(28,14);
    GOL.set(34,14);
    GOL.set(28,15);
    GOL.set(34,15);
    GOL.set(31,16);
    GOL.set(29,17);
    GOL.set(33,17);
    GOL.set(30,18);
    GOL.set(31,18);
    GOL.set(32,18);
    GOL.set(31,19);
    GOL.set(28,22);
    GOL.set(29,22);
    GOL.set(30,22);
    GOL.set(28,23);
    GOL.set(29,23);
    GOL.set(30,23);
    GOL.set(27,24);
    GOL.set(31,24);
    GOL.set(26,26);
    GOL.set(27,26);
    GOL.set(31,26);
    GOL.set(32,26);
    GOL.set(28,36);
    GOL.set(28,37);
    GOL.set(29,36);
    GOL.set(29,37);


    GOL.set(30,60+20);
    GOL.set(30,61+20);
    GOL.set(31,60+20);
    GOL.set(31,62+20);
    GOL.set(32,62+20);
    GOL.set(33,62+20);
    GOL.set(33,63+20);

    GOL.print();
    while (1)
        GOL.evolve();
    return 0;
}