HRTB

src/escapei.rs

@@ -122,7 +122,10 @@ pub fn unescape(raw: &[u8]) -> Result<Cow<[u8]>, EscapeError> {
 /// # Pre-condition
 ///
 /// The implementation of `lookup_custom_entity` is expected to operate over UTF-8 inputs.
-pub fn unescape_with<'a>(raw: &'a [u8], resolve_entity: impl Fn(&[u8]) -> Option<&str>) -> Result<Cow<'a, [u8]>, EscapeError> {
+pub fn unescape_with<'a, F>(raw: &'a [u8], resolve_entity: F) -> Result<Cow<'a, [u8]>, EscapeError>
+where
+    F: for<'b> Fn(&'b [u8]) -> Option<&'b str>, // ie. the lifetime of the closure is decoupled from the output
+{
     let mut unescaped = None;
     let mut last_end = 0;
     let mut iter = memchr::memchr2_iter(b'&', b';', raw);