On 13 September 2014 06:52, John Zwinck <jzwinck_at_[hidden]> wrote:

> I recently happened upon some code which, boiled down to its essence, was
> like this:
>
> for (int ii = 0; ii < 1; ++ii)
> {
> const std::string& str = str; // !!
> std::cout << str << std::endl;
> }
>
> My to my surprise, this code compiled (and produced a segfault at
> runtime). I say surprise because I had all warnings enabled (as errors) in
> GCC 4.7 and 4.9, yet there was no complaint. I got a good answer from
> Jonathan Wakely (http://stackoverflow.com/a/25720743/4323) explaining why
> GCC failed to catch it, but this got me thinking: why does C++ allow this
> at all?
>
> So, a proposal: perhaps in C++17 we could declare that self-initialized
> references are ill-formed. I did consider whether this might impact
> existing code; the only use case that came to mind might be SFINAE, though
> I surely have never seen it used that way.
>

FYI, this is core issue 504:

http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#504


> I would appreciate any thoughts on this, and hope I have come to the right
> place to discuss it.
>
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