error overloading operator '>>' - c++

Question

I am trying to overload the >> operator, check my code, it's the most reduced program:
#include <iostream>
#include <string>
using namespace std;
class MyClass{
private:
string bar;
int foo;
public:
MyClass(){
bar="";
foo=0;
};
istream& operator>>(istream& is){
is >> bar >> foo;
return is;
};
ostream& operator<<(ostream& os){
os << bar << foo;
return os;
};
~MyClass(){};
};
int main()
{
MyClass* a = new MyClass();
cin >> *a;
delete a;
return 0;
}
This code doesn't compile, I've googled before post my question and I found the trouble could be the most vexing parse, but i cannot imagine how to fix it.
Anyway, I don't know where is the problem, when i try to compile, the compiler throws:
First:
error: no match for ‘operator>>’ (operand types are ‘std::istream {aka std::basic_istream<char>}’ and ‘MyClass’)
cin >> *a;
~~~~^~~~~
Then, after trying to convert the types to int, double, char, etc it throws:
/usr/include/c++/6.1.1/istream:924:5: nota: candidate:
std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&&, _Tp&) [con _CharT = char; _Traits = std::char_traits<char>; _Tp = MyClass] <coincidencia cercana>
operator>>(basic_istream<_CharT, _Traits>&& __is, _Tp& __x)
^~~~~~~~
/usr/include/c++/6.1.1/istream:924:5: nota: conversion of argument 1 would be ill-formed:
error: no se puede unir el l-valor ‘std::istream {aka std::basic_istream<char>}’ a ‘std::basic_istream<char>&&’
cin >> *a;
What can I do to solve this issue?

Answer 1

Overloading the input and output operators can't be done as member functions. The reason is that when you defined the >> or << operators as member functions the object instance of the class must be on the left hand side of the operator.
Instead define the operator functions as non-member friend functions (which can be done inline in the class) like
class MyClass
{
public:
...
friend std::ostream& operator<<(std::ostream& os, MyClass const& object)
{
return os << object.bar << object.foo;
}
};

Answer 2

">>" and "<<" operators are usually not implemented as member functions because the first argument is an implicit object of that class in a member function but you can do that and it will work if you would do something like *a >> cin in your main.Other wise implement these operators as global functions as explained in the above answer.