Arguments in partial template specialization

[rincewind]

Hi,

can anybody summarise all options for partial template specialization,
for all kind of parameters (type, nontype, template)?

I *think* I understand options for partial specialization on type
parameters - in place of a template argument one can construct arbitrary
valid C++ type declaration, more or less like in "typedef" statement.

What about nontype parameters? Am I right that you cannot partially
specialize on nontype parameters at all - you either leave the parameter
as it is in the primary template, or fully specialize it by passing a
constant as an argument?

Finally, what are the options for template template parameters?

[Victor Bazarov]

rincewind wrote:

can anybody summarise all options for partial template specialization,
for all kind of parameters (type, nontype, template)?

I *think* I understand options for partial specialization on type
parameters - in place of a template argument one can construct arbitrary
valid C++ type declaration, more or less like in "typedef" statement.

What about nontype parameters? Am I right that you cannot partially
specialize on nontype parameters at all - you either leave the parameter
as it is in the primary template, or fully specialize it by passing a
constant as an argument?

Finally, what are the options for template template parameters?

Partial specialisation is not just for one-argument templates. Templates
with more than one argument can be partially specialised by specifying one
or more, but not all, arguments.

template<int i, char c> class Foo {};
template<int i> class Foo<i,'A'> {}; // partial specialisation

So, every time you narrow down the set of possible instantiations of
a template, you make it specialised. You can for example specialise this
template:

template< template<class> class container > class Foo {};

by making it a different template

template< class T > class MyContainer {};
template< class T > class Foo<MyContainer> {};

V

[rincewind]

Victor Bazarov wrote:

Partial specialisation is not just for one-argument templates.

Yes, sure, but when you narrow down the set of possible instantiations,
you do it for (at least) one template parameter. I basically asked
whether you can *partially* specialize for nontype or template parameters?

[rincewind]

Victor Bazarov wrote:

Partial specialisation is not just for one-argument templates.

Yes, sure, but when you narrow down the set of possible instantiations,
you do it for (at least) one template parameter. I basically asked
whether you can *partially* specialize for nontype or template parameters?

[JustBoo]

On Fri, 06 Jan 2006 19:14:54 +0300, rincewind <fa**@not.real> wrote:

Rincewind is that you? Makes perfect sense you double posted. I mean
your Rincewind right. :-) It's me Death.

Don't think of it as dying, said Death. Just think of it as leaving
early to avoid the rush. - Terry Pratchett (I left out the caps so as
not to freakout the netcops.) :-) Oh, too late.

[Victor Bazarov]

rincewind wrote:

Victor Bazarov wrote:

Partial specialisation is not just for one-argument templates.

Yes, sure, but when you narrow down the set of possible instantiations,
you do it for (at least) one template parameter. I basically asked
whether you can *partially* specialize for nontype or template parameters?

A non-type template argument, no. A template template argument - yes,
and I've shown it. Look again.

[puzzlecracker]

rincewind wrote:

Victor Bazarov wrote:

Partial specialisation is not just for one-argument templates.

Yes, sure, but when you narrow down the set of possible instantiations,
you do it for (at least) one template parameter. I basically asked
whether you can *partially* specialize for nontype or template parameters?

template< template<class> class container > class Foo {};

is when you want to pass generically defined types such as vectors

Foo<vector<Type> >