[C++-0X] User-defined literals

[Ed Smith-Rowland <3dw4rd at verizon dot net>]

Greetings,

I am taking a new shot at user-defined literals.
Compared to the previous attempt:
  * I have altered libcpp so that it tokenizes user defined literals in 
one chunk properly.
  * I have started work on new tree nodes and accessors.
  * I have (or am trying to) refine the checks for argument and 
template parameter.

I would like to check that template literal operators have the specific 
non-type parameter pack:
template<char...>
  Foo operator"" sluggo();

I looked through the internals documentation and didn't see much on 
this.  Could anyone give me some pointers?

Also, is there any preference for using VEC vs. TREE_CHAIN for making 
trees and accessing them?  Is one sort of "modern"?

Finally I am using compparms to verify that a literal operator argument 
list conforms to strings like:
(const char*)
(const char*, std::size_t)
(const wchar_t*, std::size_t)
...
I cant get them to work.  I built a set of global trees for the argument 
types that I want to check.  The char and number tests work.
I use things like this to build the argument lists (I neglect the return 
type).
    userdef_lit_char16_str_type
     = build_function_type_list (void_type_node, char16_array_type_node,
                 size_type_node, NULL_TREE);
I'm hoping that this matches
(const char16_t*, std::size_t)
but it doesn't.

Ideas?

Thanks,

Ed Smith-Rowland