On 23/08/2026 06:52, Simon Schröder via Std-Proposals wrote:
>
>
>> On Aug 23, 2026, at 1:24 AM, Henry Skoglund via Std-Proposals <
std-proposals@lists.isocpp.org> wrote:
>>
>> On 2026-08-23 01:12, Ville Voutilainen wrote:
>>> On Sun, 23 Aug 2026 at 00:53, Henry Skoglund via Std-Proposals
>>> <
std-proposals@lists.isocpp.org> wrote:
>>>>> For ergonomics, I'd prefer an inferface where redact returns
>>>>> std::remove_reference_t<T>&& like std::move and unredact returns T& so
>>>>> that one could do:
>>>> Thank you, pretty nice idea. As long as std::unredact() follows the same
>>>> playrules as std::redact():
>>> It's a nice idea, yes. Ted is completely correct that it's a nice
>>> idea, and could be useful for some cases.
>>>
>>> I'm not even against Ted's idea. I just want to suggest that we keep in mind
>>>
>>> return -ENOTENOUGHBANGFORTHEBUCKESPECIALLYFORTHECOMPLEXITY;
>>>
>>> I seriously don't have a strong opposing viewpoint here. Being able to
>>> poison name lookup seems handy.
>>> Being able to poison the lookup and then unpoison it.. ..seems..
>>> ..questionable. The former I could explain.
>>> The latter.. ..I would struggle to explain.
>> Yes let's agree std::redact() is the main race horse to bet on here, and a std::unredact() could be a future, separate proposal.
>
> In the beginning of this discussion, people heard std::redact and immediately thought: Can I then reuse the variable name? This clashes with std::unredact. In the most extreme case we could allow both, but only either one of them can be used; i.e. if I reuse
the variable name I can no longer unredact the “shadowed” variable.
Well, we can re-use the variable name in a separate scope. std::redact(x) makes it clear that the earlier x cannot be used.
int x = 10;
std::redact(x);
{
int x = 11;
std::cout << x << "\n";
}
// Compiler diagnostic. Makes a programmer think
std::cout << x << "\n";
However, for human reasoning, isn't it safer to use smaller functions, and avoid re-using variable names? Smaller possible control-flow paths, simpler states. Making lifetime boundaries simpler, ownership etc. Reducing accidental confusion about which value
is being used.
gcc, clang already warn with -Wshadow
How would std::redact work with this, presumably no compiler diagnostic if std::redact(x); ?
https://godbolt.org/z/chfqfffM7
Regards
Jonathan
--
Std-Proposals mailing list
Std-Proposals@lists.isocpp.org
https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals