refactor(es/decorator): Remove unsafe code

crates/swc_ecma_transforms_proposal/src/decorator_2022_03.rs

@@ -1,8 +1,4 @@
-use std::{
- collections::VecDeque,
- iter::once,
- mem::{take, transmute},
-};
+use std::{collections::VecDeque, iter::once, mem::take};
 
 use rustc_hash::FxHashMap;
 use swc_atoms::JsWord;
@@ -278,15 +274,17 @@ impl Decorator202203 {
 
  fn ensure_constructor<'a>(&mut self, c: &'a mut Class) -> &'a mut Constructor {
  let mut insert_index = 0;
- for (i, member) in c.body.iter_mut().enumerate() {
+ for (i, member) in c.body.iter().enumerate() {
  if let ClassMember::Constructor(constructor) = member {
- insert_index = i + 1;
  // decorators occur before typescript's type strip, so skip ctor overloads
  if constructor.body.is_some() {
- return unsafe {
- // Safety: We need polonius
- transmute::<&mut Constructor, &'a mut Constructor>(constructor)
- };
+ if let Some(ClassMember::Constructor(c)) = c.body.get_mut(i) {
+ return c;
+ } else {
+ unreachable!()
+ }
+ } else {
+ insert_index = i + 1;
  }
  }
  }
@@ -305,15 +303,17 @@ impl Decorator202203 {
 
  fn ensure_identity_constructor<'a>(&mut self, c: &'a mut Class) -> &'a mut Constructor {
  let mut insert_index = 0;
- for (i, member) in c.body.iter_mut().enumerate() {
+ for (i, member) in c.body.iter().enumerate() {
  if let ClassMember::Constructor(constructor) = member {
- insert_index = i + 1;
  // decorators occur before typescript's type strip, so skip ctor overloads
  if constructor.body.is_some() {
- return unsafe {
- // Safety: We need polonius
- transmute::<&mut Constructor, &'a mut Constructor>(constructor)
- };
+ if let Some(ClassMember::Constructor(c)) = c.body.get_mut(i) {
+ return c;
+ } else {
+ unreachable!()
+ }
+ } else {
+ insert_index = i + 1;
  }
  }
  }