Remove unwrap_none/expect_none from compiler/.

compiler/rustc_mir/src/interpret/memory.rs

@@ -854,7 +854,11 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> {
             Some(ptr) => ptr,
             None => {
                 // zero-sized access
-                src.next().expect_none("iterator said it was empty but returned an element");
+                assert_matches!(
+                    src.next(),
+                    None,
+                    "iterator said it was empty but returned an element"
+                );
                 return Ok(());
             }
         };
@@ -880,7 +884,11 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> {
             Some(ptr) => ptr,
             None => {
                 // zero-sized access
-                src.next().expect_none("iterator said it was empty but returned an element");
+                assert_matches!(
+                    src.next(),
+                    None,
+                    "iterator said it was empty but returned an element"
+                );
                 return Ok(());
             }
         };
@@ -894,7 +902,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> {
             let offset_ptr = ptr.offset(Size::from_bytes(idx) * 2, &tcx)?; // `Size` multiplication
             allocation.write_scalar(&tcx, offset_ptr, val.into(), Size::from_bytes(2))?;
         }
-        src.next().expect_none("iterator was longer than it said it would be");
+        assert_matches!(src.next(), None, "iterator was longer than it said it would be");
         Ok(())
     }
 

compiler/rustc_mir/src/lib.rs

@@ -7,6 +7,7 @@ Rust MIR: a lowered representation of Rust.
 #![feature(nll)]
 #![feature(in_band_lifetimes)]
 #![feature(array_windows)]
+#![feature(assert_matches)]
 #![feature(bindings_after_at)]
 #![feature(bool_to_option)]
 #![feature(box_patterns)]
@@ -18,13 +19,13 @@ Rust MIR: a lowered representation of Rust.
 #![feature(exact_size_is_empty)]
 #![feature(exhaustive_patterns)]
 #![feature(never_type)]
+#![feature(map_try_insert)]
 #![feature(min_specialization)]
 #![feature(trusted_len)]
 #![feature(try_blocks)]
 #![feature(associated_type_defaults)]
 #![feature(stmt_expr_attributes)]
 #![feature(trait_alias)]
-#![feature(option_expect_none)]
 #![feature(option_get_or_insert_default)]
 #![feature(or_patterns)]
 #![feature(once_cell)]

compiler/rustc_mir/src/transform/coverage/debug.rs

@@ -285,10 +285,8 @@ impl DebugCounters {
                 ),
             };
             counters
-                .insert(id, DebugCounter::new(counter_kind.clone(), some_block_label))
-                .expect_none(
-                    "attempt to add the same counter_kind to DebugCounters more than once",
-                );
+                .try_insert(id, DebugCounter::new(counter_kind.clone(), some_block_label))
+                .expect("attempt to add the same counter_kind to DebugCounters more than once");
         }
     }
 
@@ -479,9 +477,9 @@ impl GraphvizData {
         counter_kind: &CoverageKind,
     ) {
         if let Some(edge_to_counter) = self.some_edge_to_counter.as_mut() {
-            edge_to_counter.insert((from_bcb, to_bb), counter_kind.clone()).expect_none(
-                "invalid attempt to insert more than one edge counter for the same edge",
-            );
+            edge_to_counter
+                .try_insert((from_bcb, to_bb), counter_kind.clone())
+                .expect("invalid attempt to insert more than one edge counter for the same edge");
         }
     }
 

compiler/rustc_mir/src/transform/deduplicate_blocks.rs

@@ -86,7 +86,7 @@ fn find_duplicates<'a, 'tcx>(body: &'a Body<'tcx>) -> FxHashMap<BasicBlock, Basi
                 // The basic block was already in the hashmap, which means we have a duplicate
                 let value = *occupied.get();
                 debug!("Inserting {:?} -> {:?}", bb, value);
-                duplicates.insert(bb, value).expect_none("key was already inserted");
+                duplicates.try_insert(bb, value).expect("key was already inserted");
             }
             Entry::Vacant(vacant) => {
                 vacant.insert(bb);