[Bug libstdc++/58764] [4.9 Regression] [lwg/2193] error: converting to ‘const std::vector >’ from initializer list would use explicit constructor

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58764

--- Comment #11 from Jonathan Wakely <redi at gcc dot gnu.org> ---
OK, I'll make the noexcept conditional, which will mean losing it in C++03
mode.