An annoying question about auto in C++

I was recently asked during a C++ job interview what are the types of riN variables in the code below:

int val = 25;

int foo() { return val; }
int& foo1() { return val; }
//warning: type qualifiers ignored on function return type
/*const*/ int foo2() { return val; }
const int& foo3() { return val; }

int main()
{
  auto ri = foo(); 
  auto ri1 = foo1();
  auto ri2 = foo2();
  auto ri3 = foo3();

  //cannot bind non-const lvalue reference of type 'int&' to an rvalue of type 'int'
  //auto& ri4 = foo();
  auto& ri5 = foo1();
  //cannot bind non-const lvalue reference of type 'int&' to an rvalue of type 'int'
  //auto& ri6 = foo2();
  auto& ri7 = foo3();

  auto&& ri8 = foo();
  auto&& ri9 = foo1();
  auto&& ri10 = foo2();
  auto&& ri11 = foo3();
    
  return 0;
}

auto ignores the type qualifiers and references, so looks like the types are simply int, int& and int&&.

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