[Bug c++/79442] GCC 5.4 does not fully support N3652 (Relaxing constraints on constexpr functions)

[osemwaro.pedro at ocado dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79442

--- Comment #1 from Ose Pedro <osemwaro.pedro at ocado dot com> ---
To be more precise, it does not work under GCC 5.4.0, but does work under GCC
6.1.0. I haven't been able to find a GCC cloud service that provides 5.4.1, so
haven't been able to test that version.