https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86926
--- Comment #1 from Vladimir Reshetnikov <v.reshetnikov at gmail dot com> --- Note: the error disappears if the variable `f` is not declared `constexpr`.
v.reshetnikov at gmail dot com Sun, 12 Aug 2018 16:42:02 -0700
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86926
--- Comment #1 from Vladimir Reshetnikov <v.reshetnikov at gmail dot com> --- Note: the error disappears if the variable `f` is not declared `constexpr`.