src/test/ui/return/issue-82612-return-mutable-reference.rs

   1 // Regression test for #82612.
   2
   3 use std::marker::PhantomData;
   4
   5 pub trait SparseSetIndex {
   6     fn sparse_set_index(&self) -> usize;
   7 }
   8 pub struct SparseArray<I, V = I> {
   9     values: Vec<Option<V>>,
  10     marker: PhantomData<I>,
  11 }
  12
  13 impl<I: SparseSetIndex, V> SparseArray<I, V> {
  14     pub fn get_or_insert_with(&mut self, index: I, func: impl FnOnce() -> V) -> &mut V {
  15         let index = index.sparse_set_index();
  16         if index < self.values.len() {
  17             let value = unsafe { self.values.get_unchecked_mut(index) };
  18             value.get_or_insert_with(func) //~ ERROR mismatched types
  19         }
  20         unsafe { self.values.get_unchecked_mut(index).as_mut().unwrap() }
  21     }
  22 }
  23
  24 fn main() {}