tests/ui/borrowck/region-checker-map-closure-13665.rs

// https://github.com/rust-lang/rust/issues/13665
//@ run-pass

fn foo<'r>() {
  let maybe_value_ref: Option<&'r u8> = None;

  let _ = maybe_value_ref.map(|& ref v| v);
  let _ = maybe_value_ref.map(|& ref v| -> &'r u8 {v});
  let _ = maybe_value_ref.map(|& ref v: &'r u8| -> &'r u8 {v});
  let _ = maybe_value_ref.map(|& ref v: &'r u8| {v});
}

fn main() {
  foo();
}