template class does not like list iterator

[lowerlogic]

Here's a simple example that shows the error:

#include <list>
using namespace std;
template <class T>
class fastlist {
  public:
  list<T>::iterator begin();
  private:
  list<T> elements;
};

And I get this error:

fastlist.h:6: error: expected `;' before "begin"

It compiles fine when the member function is list<int>::iterator begin(), but I want begin() to return a list iterator for a list of class T.

[ChaosEngine]

try
typename list<T>::iterator::begin()

[lowerlogic]

Thanks.

[CodeMonkey]

try
typename list<T>::iterator::begin()

typename list<T>::iterator begin();

Because he was declaring a function (no :: before begin). But yes, typename did it. Damned semantic ambiguities.

[brewbuck]

The general rule is if you are trying to specify a fully qualified type name, AND the type name contains a template parameter (either implicitly or explicitly), AND the typename contains a scoping "::" operator, you need to put "typename" in front of the type.

You even have to do it in contexts where the fully qualified name could not be anything BUT a type, which is irritating (e.g. in the return type of a function, like in this case).