Add expressions using operator >>

Question

Consider the following snippet:

#include <iostream>

template <typename... types> void writeall(const types & ... items)
{
    (std :: cout << ... << items);
}

template <typename... types> void readall(types & ... items)
{
    (std :: cin >> ... >> items);
}

int main()
{
    writeall(1, 2, 3, 4);
    std :: cout << std :: endl;

    int a, b, c, d;
    readall(a, b, c, d);
}

In writeallI use fold expressions to feed std :: coutparameters into a package. Everything works fine, and I displayed 1234.

Q readall, I am doing exactly the same, expecting to read from a std :: cinpackage of parameters. However i get

error: expected ')'
(std :: cin >> ... >> items);

What am I doing wrong? One would expect that everything would work the same way, I just replaced the operator <<with the operator >>.