Nested struct type in a template class

Question

template <typename vec1, typename vec2>
class fakevector
{
    public:
       /* Do something */
};



template <class A>
class caller
{
    public:

    struct typeList
    {
        struct typeOne
        {
            //...
        };
    };

    typedef fakevector<typeList::typeOne,int> __methodList;  /* This will trigger compile error */

};

The error messages I got are:

1. Error: type/value mismatch at argument 1 in template parameter list for ‘template class fakevector’

2. Error: expected a type, got ‘caller::typeList::typeOne’

   If template is removed from the caller class, no error will be reported, like this

   class caller { public: struct typeList { .... };

I don't know the reason. Thank you very much!

Answer 1

Try:

 typedef fakevector<typename typeList::typeOne,int> __methodList;

http://www.comeaucomputing.com/techtalk/templates/#typename

Answer 2

Try typedef fakevector<typename typeList::typeOne,int>

The typename prefix to a name is required when the name

Appears in a template

Is qualified

Is not used as in a list of base class specifications or in a list of member initializers introducing a constructor definition

Is dependent on a template parameter

Furthermore, the typename prefix is not allowed unless at least the first three previous conditions hold.

Answer 3

Looks like the compiler is in doubt what typeOne is.

typedef fakevector<typename typeList::typeOne,int> 

should compile