The current version of GCC in the toolchain (4.9.3) is a major release behind upstream (5.3.0). GCC 6 will probably be released in the next few months as well.

Some of the major differences between 4 and 5...

• C++14 support
• C++ ABI default
• C11 as default
• Bugfixes
• Optimizer Improvements

Changelog (https://gcc.gnu.org/gcc-5/changes.html)