remove exclamation mark

[rust.git] / library / core / src / slice / index.rs

diff --git a/library/core/src/slice/index.rs b/library/core/src/slice/index.rs
index a23de54ef20e9c8cdbea18b9ed9fb68c67412c21..68de4e4e1f32a95ee9b52ac06e2deed82ee120c6 100644 (file)
--- a/library/core/src/slice/index.rs
+++ b/library/core/src/slice/index.rs
@@ -1,5 +1,6 @@
 //! Indexing implementations for `[T]`.
 
+use crate::intrinsics::assert_unsafe_precondition;
 use crate::intrinsics::const_eval_select;
 use crate::ops;
 use crate::ptr;
@@ -139,6 +140,7 @@ impl Sealed for (ops::Bound<usize>, ops::Bound<usize>) {}
 /// Implementations of this trait have to promise that if the argument
 /// to `get_(mut_)unchecked` is a safe reference, then so is the result.
 #[stable(feature = "slice_get_slice", since = "1.28.0")]
+#[rustc_diagnostic_item = "SliceIndex"]
 #[rustc_on_unimplemented(
     on(T = "str", label = "string indices are ranges of `usize`",),
     on(
@@ -219,13 +221,19 @@ unsafe fn get_unchecked(self, slice: *const [T]) -> *const T {
         // cannot be longer than `isize::MAX`. They also guarantee that
         // `self` is in bounds of `slice` so `self` cannot overflow an `isize`,
         // so the call to `add` is safe.
-        unsafe { slice.as_ptr().add(self) }
+        unsafe {
+            assert_unsafe_precondition!(self < slice.len());
+            slice.as_ptr().add(self)
+        }
     }
 
     #[inline]
     unsafe fn get_unchecked_mut(self, slice: *mut [T]) -> *mut T {
         // SAFETY: see comments for `get_unchecked` above.
-        unsafe { slice.as_mut_ptr().add(self) }
+        unsafe {
+            assert_unsafe_precondition!(self < slice.len());
+            slice.as_mut_ptr().add(self)
+        }
     }
 
     #[inline]
@@ -272,13 +280,18 @@ unsafe fn get_unchecked(self, slice: *const [T]) -> *const [T] {
         // cannot be longer than `isize::MAX`. They also guarantee that
         // `self` is in bounds of `slice` so `self` cannot overflow an `isize`,
         // so the call to `add` is safe.
-        unsafe { ptr::slice_from_raw_parts(slice.as_ptr().add(self.start), self.end - self.start) }
+
+        unsafe {
+            assert_unsafe_precondition!(self.end >= self.start && self.end <= slice.len());
+            ptr::slice_from_raw_parts(slice.as_ptr().add(self.start), self.end - self.start)
+        }
     }
 
     #[inline]
     unsafe fn get_unchecked_mut(self, slice: *mut [T]) -> *mut [T] {
         // SAFETY: see comments for `get_unchecked` above.
         unsafe {
+            assert_unsafe_precondition!(self.end >= self.start && self.end <= slice.len());
             ptr::slice_from_raw_parts_mut(slice.as_mut_ptr().add(self.start), self.end - self.start)
         }
     }