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typedef for a template class with a template class as param

Posted on 2004-09-01
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Last Modified: 2010-04-01
Good Morning,

I would like to know if there is a way that I can create a typedef for a template class that has another template in it with a variable type parameter.

for example

template<class T> class Outer{...};
template<class T> class Inner{...};

typedef Outer< Inner<class T> > NewClass;

NewClass<int> getClass() {
}

I have tried this with GCC and it tells me the "NewClass" type is not a template, therefore I cannot pass a parameter to it.

I do not want to use the proprocessor.

Thank you,
- Dave
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Question by:illusioned
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4 Comments
 
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Accepted Solution

by:
jkr earned 1000 total points
ID: 11952644
You can't - see e.g. http://www.gotw.ca/gotw/079.htm ("Template Typedef") - the key sentence is "the code in question above isn't legal for a simple reason: Today's C++ doesn't support template typedefs.". The article also offers an alternative solution.
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Expert Comment

by:havman56
ID: 11952847

This works fine on MSC

template<class T>
class Outer{

      public:
      void getClass();
      
};

template<class T>
class Inner{
      };


template <class T>
void Outer<T>:: getClass()
{


}


main()
{
      typedef Outer< Inner <int> > NewClass;

      NewClass  obj;
      obj.getClass();

}
0
 

Author Comment

by:illusioned
ID: 11953289
Thanks JKR.  

From other things that I have read this may be appearing in standard C++ in the future.  In light of this, I may end up using the preprocessor just so that I won't have to change my code when it is supported by GCC (it may even be now, but I am going to stick with GCC 3.2.3).


Thank you for the help.
- Dave
0
 
LVL 86

Expert Comment

by:jkr
ID: 11959253
You're most welcome :o)
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