Nontype class template partial specialisation

[J B 0]

Hi guys, is it possible to define partial specialisation for a class template that contains nontype parameter? I wrote a simple template example and wanted to do a specialisation for char * type. I couldn't figure out how to do it, any thoughts? My original template class is below:

template<class kind, int stack_size>
class stack {
	private:
		int count;			// Number of items in the stack
		kind data[stack_size];		// The items themselves
	public:
		// Initialise the stack
		stack (void) {
			count = 0;		// Zero the stack
		}

		// Push an item on the stack
		void push (const kind item);

		// Pop an item from the stack
		kind pop (void) {
			// Stack goes down by one
			--count;
			// Then we return the top value
			return (data[count]);
		}
};

With push() member function separately defined.

template<class kind, int stack_size>
inline void stack<kind, stack_size>::push(const kind item)
{
	data[count] = item;
	++count;
}

Now I tried to specialise the class for char *

template<int stack_size>
class stack<char *, stack_size>
{
	private:
		int count;			// Number of items in the stack
		char *data[stack_size];		// The items themselves
	public:
		// Initialise the stack
		stack (void) {
			count = 0;		// Zero the stack
		}

		// Push an item on the stack
		void push (const char *item);

		// Pop an item from the stack
		char *pop (void) {
			// Stack goes down by one
			--count;
			// Then we return the top value
			return (data[count]);
		}
};

inline void stack<char *, stack_size>::push(const char *item)      <---- error
{
				data[count] = strdup(item);
				++count;
}

The part above wouldn't compile properly. I got a compile error when it hits the push() function definition. It says the stack_size is undeclared identifier. Thanks.

[Joaquin M Lopez Munoz]

The correct syntax for the specialized member of stack::push is as follows:

template<int stack_size>
inline void stack<char*,stack_size>::push(const char* item)
{
...
}

Joaquín M López Muñoz Telefónica, Investigación y Desarrollo Want a Boost forum in Code Project? Vote here[^]!

[J B 0]

Thank you, Joaquín In addition. You can see that only stack::push() was needed to change for the specialisation. I am wondering if the C++ template standard provides a way to directly make a specialisation towrds member functions, without having to rewrite whole class specialised declaration? Thanks again.

[Joaquin M Lopez Munoz]

No, you can't partially specialize a member function. The language allows you only to fully specialize a member function. For instance, the following is valid:

// no class specialization prior to this
template<>
inline void stack<char*,1024>::push(char* const)
{
}

but I'm afraid this is not what you're after, sorry. Joaquín M López Muñoz Telefónica, Investigación y Desarrollo Want a Boost forum in Code Project? Vote here[^]!