[PATCH 1/3] Rewrite valid-expr.h's internals in terms of the detection idiom (C++17/N4502)

[Luis Machado]

On 9/28/20 3:59 PM, Tom Tromey wrote:
>>>>>> "Pedro" == Pedro Alves <pedro@palves.net> writes:
> 
> Pedro> +  static_assert (gdb::is_detected_exact<EXPR_TYPE,			\
> Pedro> +		 archetype, TYPES>::value == VALID,			\
> Pedro>  		 "");							\
> 
> 
> I'm not sure if it was exactly this patch, but after I merged this code
> to our internal tree, we started having build problems on a machine that
> uses GCC 6.4.  I've appended the error message.
> 
> I'm not sure it is worth doing anything about this, but I thought it
> would be worth noting in case anybody else winds up in this situation.
> 
> Tom

It was reported before on this thread a week or so ago. Unless GCC 6.4 
isn't supported any longer, I think it should be fixed.

If GCC 6.4 isn't supported, then we should make that explicit on the 
documentation to spare folks the trouble of having to figure it out.