Usage of class forward declarations;

[Belebele]

Why is the code below giving an error in VC++ 8? Why would the
compiler need to see the definition of Foo to compile:

class Foo;
Foo& g();
void f()
{
g(); // error: use of undefined type 'Foo'
}


?

Thanks

 

[Erik Wikström]

Why is the code below giving an error in VC++ 8? Why would the
compiler need to see the definition of Foo to compile:

class Foo;
Foo& g();
void f()
{
g(); // error: use of undefined type 'Foo'
}

Because g() returns an object of type Foo, which means that the compiler
needs to know how to create such an object.

 

[Juha Nieminen]

Because g() returns an object of type Foo, which means that the compiler
needs to know how to create such an object.

Actually it returns a reference of type Foo.