“cout”没有在这个范围内声明。

I have a C++ program:

我有一个c++程序:

#include<iostream>

int main()
{
    char t = 'f';
    char *t1;
    char **t2;
    cout<<t;    //this causes an error, cout was not declared in this scope
    return 0;
}
#include<i