Re: vector<bool> _M_start and 0 offset

[Jonathan Wakely <jwakely@redhat.com>]

On 17/09/18 20:10 +0100, Jonathan Wakely wrote:
>On 17/09/18 21:55 +0300, Ville Voutilainen wrote:
>>On Mon, 17 Sep 2018 at 21:50, Jonathan Wakely <jwakely@redhat.com> wrote:
>>>"I used C++11 syntax because I find it nicer, and the compiler accepts
>>>>it in C++98 mode with just a warning, suppressed in a standard
>>>>header."
>>>
>>>Oh sorry, I just looked at the patch and replied without reading the
>>>top bit.
>>>
>>>>Even with -Wsystem-headers I don't get a warning, I have to precompile
>>>>with -P -E then compile the result to get "warning: extended
>>>>initializer lists only available with -std=c++11 or -std=gnu++11".
>>>
>>>OK for trunk then.
>>
>>Do other compilers besides gcc suppress the same way?
>
>No, clang doesn't:
>
>In file included from bv.cc:1:
>In file included from /home/jwakely/gcc/latest/lib/gcc/x86_64-pc-linux-gnu/9.0.0/../../../../include/c++/9.0.0/vector:65:
>/home/jwakely/gcc/latest/lib/gcc/x86_64-pc-linux-gnu/9.0.0/../../../../include/c++/9.0.0/bits/stl_bvector.h:812:16: error: non-aggregate type 'std::vector<bool, type-parameter-0-0>::iterator' (aka 'std::_Bit_iterator') cannot be initialized with an initializer list
>     { return { this->_M_impl._M_start, 0 }; }

And for the avoidance of doubt, it's the same error if I make the
correct change to the header:

      { return { this->_M_impl._M_start._M_p, 0 }; }


>              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>bv.cc:6:5: note: in instantiation of member function 'std::vector<bool, std::allocator<bool> >::begin' requested here
> b.begin();
>   ^
>1 error generated.
>
>So I do think we should stick to C++98 syntax.
>