https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87300
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- Yes The first published standard to include the change was C++14 but it's a DR against the previous standard. That means it's fixing a bug in the previous standard. The -std=c++11 flag is documented to mean C++11 *plus amendments*. Also, the point of the warning is to alert you to pessimised code, which is definitely the case here. Without the std::move the code compiles and can elide the move construction. With the std::move a new object must be constructed.
