double to string

public static void main(){
    double d = 12.2627;
    stdout.printf("%s\n",double_to_string_p(d,2));
}

public string double_to_string_p(double d, int precision){
    string s = d.to_string();
    stdout.printf("%s\n",s);
    string[] a = s.split(".");
    if(a.length < 2) return s;
    a[1] = a[1].substring(0,precision);
    return string.joinv(".",a);
}