[Bug c++/81410] O3 breaks code

[m-ou.se@m-ou.se]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81410

Maurice Bos <m-ou.se@m-ou.se> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |m-ou.se@m-ou.se

--- Comment #2 from Maurice Bos <m-ou.se@m-ou.se> ---
Created attachment 41730
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=41730&action=edit
Test case without using any standard headers

Here's a test case which fails in the same way (on x86_64, Gcc 7.1.1), but
without using any standard headers. (No std::pair or std::vector.) Only fails
with -O3, with any -std=.