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Diffstat (limited to '')
-rw-r--r-- | src/test/ui/unsized/issue-40231-2.rs | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/src/test/ui/unsized/issue-40231-2.rs b/src/test/ui/unsized/issue-40231-2.rs new file mode 100644 index 000000000..780433b28 --- /dev/null +++ b/src/test/ui/unsized/issue-40231-2.rs @@ -0,0 +1,54 @@ +// check-pass + +#![allow(dead_code)] + +trait Structure<E>: Sized where E: Encoding { + type RefTarget: ?Sized; + type FfiPtr; + unsafe fn borrow_from_ffi_ptr<'a>(ptr: Self::FfiPtr) -> Option<&'a Self::RefTarget>; +} + +enum Slice {} + +impl<E> Structure<E> for Slice where E: Encoding { + type RefTarget = [E::Unit]; + type FfiPtr = (*const E::FfiUnit, usize); + unsafe fn borrow_from_ffi_ptr<'a>(_ptr: Self::FfiPtr) -> Option<&'a Self::RefTarget> { + panic!() + } +} + +trait Encoding { + type Unit: Unit; + type FfiUnit; +} + +trait Unit {} + +enum Utf16 {} + +impl Encoding for Utf16 { + type Unit = Utf16Unit; + type FfiUnit = u16; +} + +struct Utf16Unit(pub u16); + +impl Unit for Utf16Unit {} + +struct SUtf16Str { + _data: <Slice as Structure<Utf16>>::RefTarget, +} + +impl SUtf16Str { + pub unsafe fn from_ptr<'a>(ptr: <Slice as Structure<Utf16>>::FfiPtr) + -> Option<&'a Self> { + std::mem::transmute::<Option<&[<Utf16 as Encoding>::Unit]>, _>( + <Slice as Structure<Utf16>>::borrow_from_ffi_ptr(ptr)) + } +} + +fn main() { + const TEXT_U16: &'static [u16] = &[]; + let _ = unsafe { SUtf16Str::from_ptr((TEXT_U16.as_ptr(), TEXT_U16.len())).unwrap() }; +} |