Re: [C++ Patch] PR 58503

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

On 10/03/2013 03:27 PM, Jason Merrill wrote:
> On 10/03/2013 05:52 AM, Paolo Carlini wrote:
> > +      else if (!TREE_TYPE (*begin) || !TREE_TYPE (*end))
>
> This should use type_dependent_expression_p.
>
> And there should be a positive test for a dependent range that 
> exercises this code.

I see what you mean. But I'm not sure that positive test can really 
exist (that is, a positive test exercising the new code).

My point is that do_range_for_auto_deduction is called only by 
cp_parser_range_for and *only* when type_dependent_expression_p is 
*false* for the range_expr. Now, is it possible that in a range-based 
for-statement with such a range_expr, begin_expr and end_expr are 
nevertheless type-dependent?

At the moment I can't see how, given the various options in C++11, also 
summarized in the comment before cp_convert_range_for. Thus it seems to 
me that we are dealing with very specific forms of type-dependency that 
can occur only in invalid code. What do you think?

Thanks!
Paolo.