Typedef of template alias in C ++

I have the following templated class A

:

template<template<typename>class VectorT>
class A
{
      //...
}

      

        
        
        
      

    

which I create like this A<MyStdVector> objectA;

where MyStdVector

is an alias for std::vector

with a specific allocator ( MyAllocator

):

template<typename T>
using MyStdVector = std::vector<T,MyAllocator>

      

        
        
        
      

    

I decided to create an alias with a name Vector

inside A

:

template<template<typename>class VectorT>
class A
{
 public:
      template<typename T>
      using Vector = VectorT<T>;

      //...
}

      

        
        
        
      

    

so inside A

I can call Vector<int>

(instead of VectorT<int>

). More importantly, I would like to access this alias Vector

from another class B

. How to achieve this :

template<class A>
class B
{
public:
    // How to define a type Vector which refers to A::Vector 
    // such that inside B, Vector<int> refers to A::Vector<int>
    // which refers to MyStdVector<int> 
}   

      

        
        
        
      

    

to create an attribute Vector<int>

on a class B

eg. So I tried 3 things (inside a class B

):

typedef typename A::Vector Vector;   //1

template<typename T>
using Vector = typename A::Vector;   //2

template<typename T>
using Vector = typename A::Vector<T> //3

      

        
        
        
      

    

But the compiler says that typename A::Vector

is naming StdVector

which is not a type (I'm assuming it is only considered an alias and not a type?) For the first two solutions. And the last solution creates a syntax error.

Here is all the code I tried to compile:

#include <vector>

template<typename T>
using MyStdVector = std::vector<T/*,MyAllocator*/>;

template<template<typename>class VectorT>
class A
{
public:
    template<typename T>
    using Vector = VectorT<T>;

    //...
};

template<class A>
class B
{
public:
//    typedef typename A::Vector Vector;   // 1

//    template<typename T>
//    using Vector = typename A::Vector;   // 2

//    template<typename T>
//    using Vector = typename A::Vector<T>; // 3

    Vector<int> m_vector;
};

int main(int argc, char *argv[])
{
    A<MyStdVector> a;
    B<A<MyStdVector>> b;
    return 0;
}

      

        
        
        
      

    

I am confused about the difference between typedef

and alias

, especially when I want to mix them and patterns ...