problem with a structure nested within a template

problem with a structure nested within a template

[Paul Ianna]

Hi All,

I'm perplexed and hoping to obtain some guru insight from the community.

The code below is a snippet from some existing code that compiles with
many other compilers, but not gcc (I tried both 3.4.4 and 4.1.1
versions).

The problem line is:  C1<U>::Node*    pNode;

and the error is:  error: expected `;' before '*' token

If I use a concrete type (e.g., C1<int>), all is well.

Thanks in advance,
Paul


///////////////////////////////////////
template<typename T>
class C1
{
public:

   struct Node
   {
      T*     prev;
      T*     next;
   };

   Node   myNode;
};



///////////////////////////////////////
template<typename U>
class C2
{
public:

   U                       someObj;
   C1<U>::Node*    pNode;
};


///////////////////////////////////////
int main()
{
   C1<int> c1;

   C2<int> c2;

   return 0;
}

RE: problem with a structure nested within a template

[Young, Michael]

> The problem line is:  C1<U>::Node*    pNode;

I *think* this is a "type-dependent id expression" (in std lingo), because "U" is a template parameter type.
You should be able to write the following and get rid of this problem...

typename C1<U>::Node*  pNode;

HTH,
  Michael

RE: problem with a structure nested within a template

[Young, Michael]

I may have been wrong in the nomenclature - it may be a "qualified-name" (14.6 p3).  Either way, the proposed solution should work.
  - Michael