Ltac solve_field_offset_type i m :=
  let H := fresh "H" in
  let Hty := fresh "H" in
  let Hofs := fresh "H" in
  let t := fresh "t" in
  let ofs := fresh "ofs" in
  pose proof field_offset_field_type_match cenv_cs i m;
  destruct (Ctypes.field_offset cenv_cs i m) as [ofs|?] eqn:Hofs, (Ctypes.field_type i m) as [t|?] eqn:Hty;
    [clear H | inversion H | inversion H | clear H].

Lemma field_offset_no_overlap: forall i1 i2 m, i1 <> i2 -> in_members i1 m -> in_members i2 m -> field_offset cenv_cs i1 m + sizeof (field_type i1 m) <= field_offset cenv_cs i2 m \/ field_offset cenv_cs i2 m + sizeof (field_type i2 m) <= field_offset cenv_cs i1 m.