用另一个类的模板参数实例化一个模板类

Question

Is there a way to instantiate a template class ("A" in the example) with the template parameter of another class?

example:

class "A":

//A.h
template <size_t size> 
class A
{
  void doSmt()
  {
     // do something with size
  }
};

class "B":

//B.h
#include "A.h"
template<typename V>
class B
{
  void doSmt2(A<V> a)  //Error Here
  {
    //do something with a
  }
};

Error I got: Error 1

error C2993: 'V' : illegal type for non-type template parameter 'size'  

Answer 1

Yes. Your issue is that V is a type parameter, whereas size is a size_t parameter. Just make them match.

template <std::size_t V>
class B
{
    void doSmt2(A<V> a)
    {
    }
};

Answer 2

The template type of A is a non-type template parameter. In B we have a type template parameter. These are not compatible. What you need to do is add the non-type template parameter type to B

template<size_t size>
class B
{
  void doSmt2(A<size> a)
  {
    //do something with a
  }
};