https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101651
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #2)
Here is clang's error message which is 10000% wrong.
<source>:7:16: error: constexpr function never produces a constant expression
[-Winvalid-constexpr]
constexpr auto gen () {
^
<source>:11:18: note: subexpression not valid in a constant expression
ret[i] = ret1[0];
^
1 error generated.
Compiler returned: 1
