[Bug c++/91774] Assignment from return value of function to reference returned by function occasionally produces wrong results

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91774

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
[expr.ass] "The right operand is sequenced before the left operand."