[RFC] Deprecate "implicit int" for main() in C++

[Jonathan Wakely]

On 25/04/18 14:59 +0100, Andrew Haley wrote:
>On 04/25/2018 02:56 PM, Jason Merrill wrote:
>> The warning by default seems sufficient to me.
>
>Yes.  We've been bitten by this a few times, with mysterious crashes.
>I'm not sure it even makes sense only to be a warning, but I guess
>that's up to the C++ TC.

It's not always possible for the compiler to prove that flowing off
the end never happens, even if the program state ensures that it can't
(e.g. by all callers enforcing the function's preconditions
correctly). So making it ill-formed is deemed too draconian whenever
this gets discussed.