n.builtins.Buf: require t:{`Moveable `Trivial_ctor `Default_dtor}
n.builtins.Buf: require t:{`Moveable `Trivial_ctor `Default_dtor}

There are still some questions here. A large subset of Buf doesn't
depend on these operations: even Push can be performed on a
non-`Trivial_ctor type (at least with the help of ::init tracking by the
semantic engine). We don't want to push people away from Buf because of
stringent requirements, to have them reimplement it by hand and get it
wrong.

nanocritical/n,nanocritical/n,nanocritical/n,nanocritical/n