[Bug c++/101557] the value of '' is not usable in a constant expression

[federico.kircheis at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101557

--- Comment #2 from Federico Kircheis <federico.kircheis at gmail dot com> ---
clang does not reject it:

https://godbolt.org/z/8Mq1e3o3j