There has always been incompatibilities and other issues between g++/libstdc++ versions, this is nothing new. It's more the fault of the GNU Project for having half-assed support for C++11 in the first place.
As the name suggests, C++11 was approved by ISO in 2011, and GCC 5 just recently finalized support for it, that's four years of development. C++14 is already 8 months old and GCC 5 doesn't have full support for it.
libstdc++ is always going to have some issues with each new version of C++. This is not unique to C++ either, Java, PHP, and Python, all come to mind, and JavaScript... JavaScript is a mess.
Personally, I don't like C++ because it's ugly and doesn't offer anything significant that C doesn't have.
As the name suggests, C++11 was approved by ISO in 2011, and GCC 5 just recently finalized support for it, that's four years of development. C++14 is already 8 months old and GCC 5 doesn't have full support for it.
libstdc++ is always going to have some issues with each new version of C++. This is not unique to C++ either, Java, PHP, and Python, all come to mind, and JavaScript... JavaScript is a mess.
Personally, I don't like C++ because it's ugly and doesn't offer anything significant that C doesn't have.