class calculate {
　int _count;
public:
　calculate() : _count(0) {}
　double operator()() {
　　　return sin(2.0 * M_PI * 1000.0 * (double)(_count++)/8000.0);
　}
};

std::vector<double> tbl(256, 0.0);
std::generate(tbl.begin(), tbl.end(), calculate());