Add debug assertions to some unsafe functions

These debug assertions are all implemented only at runtime using
`const_eval_select`, and in the error path they execute
`intrinsics::abort` instead of being a normal debug assertion to
minimize the impact of these assertions on code size, when enabled.

Of all these changes, the bounds checks for unchecked indexing are
expected to be most impactful (case in point, they found a problem in
rustc).

1 files changed, 4 insertions, 4 deletions

diff --git a/compiler/rustc_data_structures/src/map_in_place.rs b/compiler/rustc_data_structures/src/map_in_place.rs
index 5dd9fc6e8bc..874de03d37a 100644
--- a/compiler/rustc_data_structures/src/map_in_place.rs
+++ b/compiler/rustc_data_structures/src/map_in_place.rs
@@ -30,13 +30,13 @@ impl<T> MapInPlace<T> for Vec<T> {
             while read_i < old_len {
                 // move the read_i'th item out of the vector and map it
                 // to an iterator
-                let e = ptr::read(self.get_unchecked(read_i));
+                let e = ptr::read(self.as_ptr().add(read_i));
                 let iter = f(e).into_iter();
                 read_i += 1;
 
                 for e in iter {
                     if write_i < read_i {
-                        ptr::write(self.get_unchecked_mut(write_i), e);
+                        ptr::write(self.as_mut_ptr().add(write_i), e);
                         write_i += 1;
                     } else {
                         // If this is reached we ran out of space
@@ -76,13 +76,13 @@ impl<T, A: Array<Item = T>> MapInPlace<T> for SmallVec<A> {
             while read_i < old_len {
                 // move the read_i'th item out of the vector and map it
                 // to an iterator
-                let e = ptr::read(self.get_unchecked(read_i));
+                let e = ptr::read(self.as_ptr().add(read_i));
                 let iter = f(e).into_iter();
                 read_i += 1;
 
                 for e in iter {
                     if write_i < read_i {
-                        ptr::write(self.get_unchecked_mut(write_i), e);
+                        ptr::write(self.as_mut_ptr().add(write_i), e);
                         write_i += 1;
                     } else {
                         // If this is reached we ran out of space