https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121677
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution|--- |INVALID
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Csaba Ráduly from comment #0)
> int i = 42;
> auto f = [&i] () { return i * 2; }; // not called
> f.__i = 13;
Your code has undefined behaviour because you're using a reserved identifier.
The point of reserving names like __i for the implementation is to allow them
to be used by the implementation *for any purpose*, including as members of
unspecified types like lambda closures.
> This should not happen. __i is not defined anywhere (clang and msvc reject
> the code because of this). User code should not have access to the internal
> implementation of lambdas.
There's no way to access it without undefined behaviour, so a valid program
cannot access it.
