TITLE: Partial template specialization

PROBLEM: mossner@kotw0002.mch.sni.de (Werner Mossner)

I've questions regarding the specialization of templates with more
than one parameter:

Is it possible to specialize such a template in only one of its
parameter? 


RESPONSE: clamage@Eng.Sun.COM (Steve Clamage), 10 Aug 95

It is allowed by the draft standard, but few if any C++ implementations
support it yet. It is a new language addition.

If yes, what is the correct syntax for doing it?

Example:

	template< class T, class U, int I > class A { // the primary template
		...
	};

	template< class T, class U > class A< T, U, 10 > { // partial specialization
		...
	};
	template< class T, int I > class A< class T, double, I > { // another partial
	};

That is, you omit the specialized items from the parameter list that
follows "template", and use a template-id in place of a template-name
in the header. When instantiating a template, partial specializations
are checked before the primary (unspecialized) template is used. The
full set of rules is pretty complicated.

	A<double, int, 10> a1; // uses first partial specialization
	A<int, double, 20> a2; // uses second partial specialization
	A<double, int, 30> a3; // uses primary template