C ++模板-基础

Question

I'm trying to follow my college notes, and I've tried googling the error and looking on stackover flow but I can't seem to figure out whats wrong.

I've read on so many places that you need to have both implementation and specification files in one file (header) so I've done so. I've just copy and pasted from my printed slides, and have googled this and tried copying exactly what was written on the page and still I get errors. I'm using g++ compiler.

Anyway, here is my code.

template<class A_Type> 
class calc
{
  public:
    A_Type multiply(A_Type x, A_Type y);
    A_Type add(A_Type x, A_Type y);
};

template<class A_type> 
A_Type calc<A_Type>::multiply(A_Type x, A_Type y)
{
  return x*y;
}
template<class A_Type> 
A_Type calc<A_Type>::add(A_Type x, A_Type y)
{
  return x+y;
}

And I get the error: expected constructor, destructor, or type conversion before 'calc' (on line 10 of test.h)

Am I missing something? I dont get it

Answer 1

template<class A_type>                            // lowercase t in A_type
A_Type calc<A_Type>::multiply(A_Type x, A_Type y) // uppercase T's in A_Type

Answer 2

您的多重定义说template <class A_type> （小写的“ t”），然后在其他地方使用大写。