Re: [C++ Patch] PR 18747

[Paolo Carlini <paolo dot carlini at oracle dot com>]

On 08/23/2012 05:24 PM, Jason Merrill wrote:
> On 08/23/2012 10:04 AM, Paolo Carlini wrote:
> > +    if (decl
> > +    && TREE_CODE (decl) == VAR_DECL
> > +    && ! TYPE_P (CP_DECL_CONTEXT (decl)))
> > +      {
> > +    error_at (decl_spec_token_start->location,
> > +          "%qT is not a template type", TREE_TYPE (decl));
> > +    decl = error_mark_node;
> > +      }
>
> Can we just check whether decl has DECL_TEMPLATE_INFO at this point?
I tried, possibly together with a preliminary DECL_LANG_SPECIFIC check 
and maybe a check that decl isn't already error_mark_node, but anyway 
apparently the idea has issues with friends, testcases like 
template/friend17.C (gave me already headaches earlier today, that's why 
I'm so quick at replying ;)

template <class T>
struct X {
  template <class U> void operator+=(U);

  template <class V>
  template <class U>
  friend void X<V>::operator+=(U);
};

int main() {
  X<int>() += 1.0;
}

when we parse the friend declaration, DECL_TEMPLATE_INFO is not set.

Paolo.