[PATCH] PR c++/52343 - error with alias template as template template argument

[Dodji Seketeli]

Gabriel Dos Reis <gdr@integrable-solutions.net> writes:

G> On Sun, Dec 23, 2012 at 11:04 PM, Jason Merrill <jason@redhat.com> wrote:
>> On 12/21/2012 07:35 AM, Dodji Seketeli wrote:
>>>
>>>     else if (TREE_TYPE (t)
>>>            && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
>>> -          && !TREE_CONSTANT (t))
>>> +          && !TREE_CONSTANT (t)
>>> +          /* Class template and alias template arguments should be OK.
>>> */
>>> +          && !DECL_TYPE_TEMPLATE_P (t))
>>
>>
>> Instead, let's add a previous else if to catch template template arguments
>> (and do nothing) so that when we hit this else if, we know we're dealing
>> with a non-type argument.
>
> Thanks; that would make the logic clearer.  I would suggest that we
> abstract this series of conjunction into a separate (static inline)
> function, e.g. nontype_argument_p.

These conjunctions represents a non-type argument only if they are
satisfied /and/ the previous 'if' branches are not taken.  So just
putting the conjunctions in e.g, nontype_argument_p could be seen as
confusion too, IMHO.

Could we just consider that the patch + comment of my earlier message and the
comment of these conjunctions

   /* A non-type argument of integral or enumerated type must be a
      constant.  */

should make this less confusing?

-- 
		Dodji