[Bug c++/52119] [C++11] overflow in signed left shift isn't diagnosed

[jyasskin at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52119

--- Comment #12 from Jeffrey Yasskin <jyasskin at gcc dot gnu.org> ---
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/n3675.html#1457 changed
this between C++11 and C++14.