Rollup of 6 pull requests

compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs

@@ -2346,6 +2346,17 @@ impl<'a, 'b, 'tcx> FnCallDiagCtxt<'a, 'b, 'tcx> {
                         provided_span,
                         format!("unexpected argument{idx}{provided_ty_name}"),
                     ));
+                    if self.provided_arg_tys.len() == 1
+                        && let Some(span) = self.maybe_suggest_expect_for_unwrap(provided_ty)
+                    {
+                        err.span_suggestion_verbose(
+                            span,
+                            "did you mean to use `expect`?",
+                            "expect",
+                            Applicability::MaybeIncorrect,
+                        );
+                        continue;
+                    }
                     let mut span = provided_span;
                     if span.can_be_used_for_suggestions()
                         && self.call_metadata.error_span.can_be_used_for_suggestions()
@@ -2776,6 +2787,22 @@ impl<'a, 'b, 'tcx> FnCallDiagCtxt<'a, 'b, 'tcx> {
 
         (suggestion_span, suggestion)
     }
+
+    fn maybe_suggest_expect_for_unwrap(&self, provided_ty: Ty<'tcx>) -> Option<Span> {
+        let tcx = self.tcx();
+        if let Some(call_ident) = self.call_metadata.call_ident
+            && call_ident.name == sym::unwrap
+            && let Some(callee_ty) = self.callee_ty
+            && let ty::Adt(adt, _) = callee_ty.peel_refs().kind()
+            && (tcx.is_diagnostic_item(sym::Option, adt.did())
+                || tcx.is_diagnostic_item(sym::Result, adt.did()))
+            && self.may_coerce(provided_ty, Ty::new_static_str(tcx))
+        {
+            Some(call_ident.span)
+        } else {
+            None
+        }
+    }
 }
 
 struct ArgMatchingCtxt<'a, 'b, 'tcx> {

library/alloc/src/lib.rs

@@ -106,6 +106,7 @@
 #![feature(const_destruct)]
 #![feature(const_eval_select)]
 #![feature(const_heap)]
+#![feature(const_index)]
 #![feature(const_option_ops)]
 #![feature(const_try)]
 #![feature(copied_into_inner)]

library/alloc/src/vec/mod.rs

@@ -3747,7 +3747,8 @@ impl<T: TrivialClone, A: Allocator> ExtendFromWithinSpec for Vec<T, A> {
 ////////////////////////////////////////////////////////////////////////////////
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T, A: Allocator> ops::Deref for Vec<T, A> {
+#[rustc_const_unstable(feature = "const_convert", issue = "143773")]
+impl<T, A: Allocator> const ops::Deref for Vec<T, A> {
     type Target = [T];
 
     #[inline]
@@ -3757,7 +3758,8 @@ impl<T, A: Allocator> ops::Deref for Vec<T, A> {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T, A: Allocator> ops::DerefMut for Vec<T, A> {
+#[rustc_const_unstable(feature = "const_convert", issue = "143773")]
+impl<T, A: Allocator> const ops::DerefMut for Vec<T, A> {
     #[inline]
     fn deref_mut(&mut self) -> &mut [T] {
         self.as_mut_slice()
@@ -3822,7 +3824,8 @@ impl<T: Hash, A: Allocator> Hash for Vec<T, A> {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T, I: SliceIndex<[T]>, A: Allocator> Index<I> for Vec<T, A> {
+#[rustc_const_unstable(feature = "const_index", issue = "143775")]
+impl<T, I: [const] SliceIndex<[T]>, A: Allocator> const Index<I> for Vec<T, A> {
     type Output = I::Output;
 
     #[inline]
@@ -3832,7 +3835,8 @@ impl<T, I: SliceIndex<[T]>, A: Allocator> Index<I> for Vec<T, A> {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T, I: SliceIndex<[T]>, A: Allocator> IndexMut<I> for Vec<T, A> {
+#[rustc_const_unstable(feature = "const_index", issue = "143775")]
+impl<T, I: [const] SliceIndex<[T]>, A: Allocator> const IndexMut<I> for Vec<T, A> {
     #[inline]
     fn index_mut(&mut self, index: I) -> &mut Self::Output {
         IndexMut::index_mut(&mut **self, index)