On Saturday, 6 April 2019 at 12:20:28 UTC, Alex wrote: > Error: variable > `std.traits.ParameterDefaults!(foo).Get!1u.Get` only parameters > or stack based variables can be `inout` so i think that is a bug in the phobos library see: https://forum.dlang.org/thread/qbqvkcoexxtlvlxobzxn@forum.dlang.org