https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70213
--- Comment #1 from xyzdragon at fastmail dot fm --- I just noticed, that as a workaround the it works to change isConst<T>()
xyzdragon at fastmail dot fm Sat, 12 Mar 2016 05:54:33 -0800
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70213
--- Comment #1 from xyzdragon at fastmail dot fm --- I just noticed, that as a workaround the it works to change isConst<T>()