[cfe-dev] Getting the corresponding template parameters of a template argument list in partial template specializations

[Douglas Gregor]

On Jul 26, 2010, at 2:40 AM, Olivier wrote:

> Hi,
> 
> I'm trying to figure out how I can retrive the template parameters that 
> correspond to certain template arguments in the template argument list of a 
> partial template specialization (ouf), i.e. :
> 
> template< typename Tp0, int N0, typename Tp1, int N1 >
>    struct Foo
>    { /* ... */ }
> 
> template< typename Tp0, int N1 >
>    struct Foo<Tp0,1,short,N1>
>    { /* ... */ }
> 
> In this example, the TemplateArgumentList object I get from the 
> ClassTemplatePartialSpecializationDecl will contain 4 template arguments :
> 
>  - One of kind TemplateArgument::Type
>  - One of kind TemplateArgument::Integral
>  - One of kind TemplateArgument::Type
>  - One of kind TemplateArgument::Expression
> 
> And a TemplateParameters of two elements.
> 
> I can't seem to figure out how to get the identifier of template arguments of 
> type TemplateArgument::Expression. How can I achieve this ?

Get the expression (an Expr*) from the template argument. It'll be a DeclRefExpr that refers to the NonTypeTemplateParmDecl for N1.

> As a more general question, I would like to be able to print 
> out "<Tp0,1,short,N1>" from the corresponding 
> ClassTemplatePartialSpecialization object. What is the best way to do this ?


ClassTemplatePartialSpecializationDecl::getTemplateArgsAsWritten() will give you the template arguments as written.

	- Doug