Rollup merge of #67125 - hashedone:master, r=petrochenkov

Added ExactSizeIterator bound to return types

Fixes #66865

src/librustc/mir/mod.rs

@@ -278,15 +278,15 @@ impl<'tcx> Body<'tcx> {
 
  /// Returns an iterator over all function arguments.
  #[inline]
- pub fn args_iter(&self) -> impl Iterator<Item = Local> {
+ pub fn args_iter(&self) -> impl Iterator<Item = Local> + ExactSizeIterator {
  let arg_count = self.arg_count;
- (1..=arg_count).map(Local::new)
+ (1..arg_count + 1).map(Local::new)
  }
 
  /// Returns an iterator over all user-defined variables and compiler-generated temporaries (all
  /// locals that are neither arguments nor the return place).
  #[inline]
- pub fn vars_and_temps_iter(&self) -> impl Iterator<Item = Local> {
+ pub fn vars_and_temps_iter(&self) -> impl Iterator<Item = Local> + ExactSizeIterator {
  let arg_count = self.arg_count;
  let local_count = self.local_decls.len();
  (arg_count + 1..local_count).map(Local::new)
@@ -2380,11 +2380,15 @@ impl<'tcx> UserTypeProjections {
  UserTypeProjections { contents: projs.collect() }
  }
 
- pub fn projections_and_spans(&self) -> impl Iterator<Item = &(UserTypeProjection, Span)> {
+ pub fn projections_and_spans(&self)
+ -> impl Iterator<Item = &(UserTypeProjection, Span)> + ExactSizeIterator
+ {
  self.contents.iter()
  }
 
- pub fn projections(&self) -> impl Iterator<Item = &UserTypeProjection> {
+ pub fn projections(&self)
+ -> impl Iterator<Item = &UserTypeProjection> + ExactSizeIterator
+ {
  self.contents.iter().map(|&(ref user_type, _span)| user_type)
  }