error: request for member '..' in '..' which is of non-class type

Parenthesis is not required to instantiate a class object when you don't intend to use a parameterised constructor.

Just use Foo foo2;

It will work.

Just for the record..

It is actually not a solution to your code, but I had the same error message when incorrectly accessing the method of a class instance pointed to by myPointerToClass, e.g.

MyClass* myPointerToClass = new MyClass();
myPointerToClass.aMethodOfThatClass();

where

myPointerToClass->aMethodOfThatClass();

would obviously be correct.

Foo foo2();

change to

Foo foo2;

You get the error because compiler thinks of

Foo foo2()

as of function declaration with name 'foo2' and the return type 'Foo'.

But in that case If we change to Foo foo2 , the compiler might show the error " call of overloaded ‘Foo()’ is ambiguous".