I see lots of problems about cout/cin , most of them are telling that cin/cout are slow and it's better to use scanf/printf;

but cin/cout are prettier and more easy to code for c++ coders. so i try to make an IO that it's pretty and fast.

#include <bits/stdc++.h>

using namespace std;

class FastIO{
public:
    //Output operators :
    inline FastIO & operator << (const int &a){ printf("%d" , a); return *this; }
    inline FastIO & operator << (const long long &a){ printf("%I64d" , a); return *this; }
    inline FastIO & operator << (const double &a){ printf("%.9f" , a); return *this; }
    inline FastIO & operator << (const long double &a){ printf("%.9lf" , a); return *this; }
    inline FastIO & operator << (const char * const&a){ printf("%s" , a); return *this; }
    inline FastIO & operator << (const string &a){ printf("%s" , a.c_str()); return *this; }
    //Input operators :
    inline FastIO & operator >> (int &a){ scanf("%d" , &a); return *this; }
    inline FastIO & operator >> (long long &a){ scanf("%I64d" , &a); return *this; }
    inline FastIO & operator >> (double &a){ scanf("%lf" , &a); return *this; }
    inline FastIO & operator >> (long double &a){ scanf("%lf" , &a); return *this; }
    inline FastIO & operator >> (char * const&a){ scanf("%s" , a); return *this; }
}fastIO;//you can change it to cin/cout 

int main(){
    int a;long long b;double c;
    fastIO >> a >> b >> c << a << " , " << b << " , " << c << "\n";
}