Question

I’m trying to port a C++ project to iOS. It compiles just fine in QtCreator on Linux and Windows and also on MSVC.
Now on Xcode/GCC, with a certain templated class I get the following error: “error: too few template-parameter-lists”.

The code that causes this error looks something like this:

template <typename TA, typename TB, int Type>
class MyClassImpl
{
public:
   MyClassImpl();
   virtual int GetType() const
   {
       return type;
   }
};    

typedef MyClassImpl<float, int, 12> MyFloatIntClass;

MyFloatIntClass::MyFloatIntClass()
{
...
}

int MyFloatIntClass::GetType() const
{
   return 22;
}

I’m guessing that something about the typedef syntax is illegal and GCC is more strict on the standard.
Can anybody tell me what exactly the problem is and how I can fix it?

Answer 1

This is just a guess, but do you need to add template<>?

Since it’s a template specialization, I believe it still needs to be a template.

ex.

template<>
MyFloatIntClass::MyClassImpl() {}

template<>
int MyFloatIntClass::GetType() const {
    return 22;
}

EDIT: From modelnine’s answer- turns out it needs the untypedef’d name for the ctor.

EDIT2: The following code works fine for me:

template <typename TA, typename TB, int Type>
class MyClassImpl
{
public:
   MyClassImpl();
   MyClassImpl(const MyClassImpl<TA, TB, Type>&);
   virtual int GetType() const
   {
       return Type;
   }
   const MyClassImpl<TA, TB, Type>& operator=(const MyClassImpl<TA, TB, Type>&);
};    

typedef MyClassImpl<float, int, 12> MyFloatIntClass;

template<>
MyFloatIntClass::MyClassImpl()
{
 //
}

template<>
MyFloatIntClass::MyClassImpl( const MyFloatIntClass& rhs )
{
 //
}

template<>
const MyFloatIntClass& MyFloatIntClass::operator=( const MyFloatIntClass& rhs )
{
  return *this;
}

template<>
int MyFloatIntClass::GetType() const
{
   return 22;
}