error[E0271]: expected `from_utf8_lossy` to be a fn item that returns `String`, but it returns `Cow<'_, str>`
 --> tests/ui/bad_parse_with_map.rs:5:60
  |
3 | #[derive(BinRead)]
  |          ------- required by a bound introduced by this call
4 | struct Foo {
5 |     #[br(parse_with = until_eof::<_, _, _, Vec<u8>>, map = String::from_utf8_lossy)]
  |                                                            ^^^^^^^^^^^^^^^^^^^^^^^ expected `String`, found `Cow<'_, str>`
  |
  = note: expected struct `String`
               found enum `Cow<'_, str>`
note: required by a bound in `coerce_fn`
 --> src/private.rs
  |
  | pub fn coerce_fn<R, T, F>(f: F) -> F
  |        --------- required by a bound in this function
  | where
  |     F: FnMut(T) -> R,
  |                    ^ required by this bound in `coerce_fn`

error[E0308]: `?` operator has incompatible types
 --> tests/ui/bad_parse_with_map.rs:5:23
  |
5 |     #[br(parse_with = until_eof::<_, _, _, Vec<u8>>, map = String::from_utf8_lossy)]
  |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `&[u8]`, found `Vec<u8>`
  |
  = note: `?` operator cannot convert from `Vec<u8>` to `&[u8]`
  = note: expected reference `&[u8]`
                found struct `Vec<u8>`
note: return type inferred to be `&[u8]` here
 --> tests/ui/bad_parse_with_map.rs:5:23
  |
5 |     #[br(parse_with = until_eof::<_, _, _, Vec<u8>>, map = String::from_utf8_lossy)]
  |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: consider borrowing here
  |
5 |     #[br(parse_with = &until_eof::<_, _, _, Vec<u8>>, map = String::from_utf8_lossy)]
  |                       +

error[E0308]: mismatched types
 --> tests/ui/bad_parse_with_map.rs:5:60
  |
5 |       #[br(parse_with = until_eof::<_, _, _, Vec<u8>>, map = String::from_utf8_lossy)]
  |  ____________________________________________________________^
6 | |     a: String,
  | |     ^- ------ expected due to this
  | |     ||
  | |_____|help: try using a conversion method: `.to_string()`
  |       expected `String`, found `Cow<'_, str>`
  |
  = note: expected struct `String`
               found enum `Cow<'_, str>`