Re: [C++ Patch] PR 18747

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

Hi,

On 09/06/2012 02:03 AM, Jason Merrill wrote:
> > but note that for:
> >
> > template <class T>
> > struct A
> > {
> >     int select() { return 0; }
> > };
> >
> > we have parser->num_template_parameter_lists == 1 and num_templates ==
> > 0. Thus it seems that the case 'num_templates + 1' isn't (just) about
> > member templates...
>
> That's odd, num_templates should be 1.
Yes, it seems odd, the same happens for template functions, like simply:

template <class T>
void foo();

Really, whatever we do at least the comment should be adjusted not to 
mention only member templates.
>   And I notice that cp_parser_check_declarator_template_parameters has
> another copy of the num_template_headers_for_class logic; they should
> be merged.
Something like the attached passes testing, the clean-up is nice, but 
I'm not sure about the specific details of the existing code vs 
num_template_headers_for_class, whether we can just call the latter as I 
did and be done.
> I think the problem with 24314 is that we try to decide how many
> template headers we want before we determine what declaration we're
> looking at.  When we have a redefinition or specialization, we know
> exactly how many headers we want, and we should check accordingly
> rather than say N or N+1.
I see. Yesterday at some point I wondered whether we could do that 
already when cp_parser_check_template_parameters is called, that is 
remove the + 1 case and make the callers more precise. But I understand 
not that it's too early. Then, are you under the impression that we 
should still have cp_parser_check_template_parameters as-is and add a 
check later, or have only the late one?

I'm looking more into this.

Thanks,
Paolo.

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