src/test/ui/unsized/issue-40231-1.rs

   1 // check-pass
   2
   3 #![allow(dead_code)]
   4
   5 trait Structure<E>: Sized where E: Encoding {
   6     type RefTarget: ?Sized;
   7     type FfiPtr;
   8     unsafe fn borrow_from_ffi_ptr<'a>(ptr: Self::FfiPtr) -> Option<&'a Self::RefTarget>;
   9 }
  10
  11 enum Slice {}
  12
  13 impl<E> Structure<E> for Slice where E: Encoding {
  14     type RefTarget = [E::Unit];
  15     type FfiPtr = (*const E::FfiUnit, usize);
  16     unsafe fn borrow_from_ffi_ptr<'a>(_ptr: Self::FfiPtr) -> Option<&'a Self::RefTarget> {
  17         panic!()
  18     }
  19 }
  20
  21 trait Encoding {
  22     type Unit: Unit;
  23     type FfiUnit;
  24 }
  25
  26 trait Unit {}
  27
  28 enum Utf16 {}
  29
  30 impl Encoding for Utf16 {
  31     type Unit = Utf16Unit;
  32     type FfiUnit = u16;
  33 }
  34
  35 struct Utf16Unit(pub u16);
  36
  37 impl Unit for Utf16Unit {}
  38
  39 type SUtf16Str = SeStr<Slice, Utf16>;
  40
  41 struct SeStr<S, E> where S: Structure<E>, E: Encoding {
  42     _data: S::RefTarget,
  43 }
  44
  45 impl<S, E> SeStr<S, E> where S: Structure<E>, E: Encoding {
  46     pub unsafe fn from_ptr<'a>(_ptr: S::FfiPtr) -> Option<&'a Self> {
  47         panic!()
  48     }
  49 }
  50
  51 fn main() {
  52     const TEXT_U16: &'static [u16] = &[];
  53     let _ = unsafe { SUtf16Str::from_ptr((TEXT_U16.as_ptr(), TEXT_U16.len())).unwrap() };
  54 }