Hm .. who said,(in the context of C++ talk): "don't be clever unless you really have to"?
I'm not really sure what that means?
Either way, my personal preference would be in support of Richard Hodges's suggestion. I've found GCC's expression statements to be useful in the past, and I think standardising it would be a perfect solution for this. It avoids the weirdness of having an initializer only for ternary operators that Ville Voutilainen mentioned (due to the syntax of ternaries) whilst also providing a way for scope to yield a value.
All that remains now is for someone to write a paper, in which is laid out the motivating use case, a demonstration that existing language features are limiting productivity and an impact assessment.
There is already a compiler supporting the feature, so that's in the paper's favour.
I suspect the biggest problems would be:
a) convincing everyone that the existing lambda syntax is not sufficient
b) convincing other compiler vendors to bother to implement the feature.
On Fri, 11 Sep 2020 at 10:58, Dusan Jovanovic (DBJ) <
dbj@dbj.org> wrote:
Hm .. who said,(in the context of C++ talk): "don't be clever unless you really have to"?
if (auto i = m.find(x); i == m.end())
return nullptr;
else
return std::addressof(i->second);
This works fine when returning from a function, but not as well when storing a local value.
On 2020-09-11 at 08:56, Richard Hodges via Std-Proposals wrote:
> GCC already has expression statements as an extension.
>
> I don't think it would hurt to standardise this into the language.
>
> https://godbolt.org/z/sb63dz
>
> e.g.:
> return ({
> auto i = m.find(x) ;
> i == m.end() ? nullptr : std::addressof(i->second);
> });
>
What's the supposed advantage of using a ternary operator here?
Note that gcc/godbolt produces *exactly* the same machine code for
if (auto i = m.find(x); i == m.end())
return nullptr;
else
return std::addressof(i->second);
>
> On Fri, 11 Sep 2020 at 09:19, Dmitry Dmitry via Std-Proposals
> <std-proposals@lists.isocpp.org <mailto:std-proposals@lists.isocpp.org>>
> wrote:
>
> Just write and use a find wrapper like these:
>
>
> It was just an example.
> If we start considering solving it via wrappers/helpers, then I
> would just create something like findOr(key, value) function.
>
> But, anyway, it seems that the idea is not worth it...
> Thanks for the feedback.
>
> --
> Dmitry
> *_Sent from gmail_*
--
Std-Proposals mailing list
Std-Proposals@lists.isocpp.org
https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals
Std-Proposals mailing list
Std-Proposals@lists.isocpp.org
https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals
Std-Proposals mailing list
Std-Proposals@lists.isocpp.org
https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals