Type of nested structure in 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 appeared:

• Error: type / value mismatch in argument 1 in the template parameter list for the 'fakevector' template class

• Error: expected type, received 'caller :: typeList :: typeOne

  If the template is removed from the class of the caller, it will be reported without errors like this

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

I do not 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

It seems that the compiler doubts what typeOne is.

typedef fakevector<typename typeList::typeOne,int> 

should compile

Answer 3

typedef fakevector<typename typeList::typeOne,int>

A prefix typenamefor the name is required if the name

Appears in the template.

Is qualified

It is not used both in the list of specifications of the base class and in the list of element initializers by entering a constructor definition

depends on template parameter

In addition, the prefix is typenamenot allowed if at least the first three previous conditions are not met.