1 files changed, 25 insertions, 0 deletions
diff --git a/vendor/syn/src/discouraged.rs b/vendor/syn/src/discouraged.rs
index a46129b6a..fb98d6332 100644
--- a/vendor/syn/src/discouraged.rs
+++ b/vendor/syn/src/discouraged.rs
@@ -1,6 +1,7 @@
 //! Extensions to the parsing API with niche applicability.
 
 use super::*;
+use proc_macro2::extra::DelimSpan;
 
 /// Extensions to the `ParseStream` API to support speculative parsing.
 pub trait Speculative {
@@ -192,3 +193,27 @@ impl<'a> Speculative for ParseBuffer<'a> {
             .set(unsafe { mem::transmute::<Cursor, Cursor<'static>>(fork.cursor()) });
     }
 }
+
+/// Extensions to the `ParseStream` API to support manipulating invisible
+/// delimiters the same as if they were visible.
+pub trait AnyDelimiter {
+    /// Returns the delimiter, the span of the delimiter token, and the nested
+    /// contents for further parsing.
+    fn parse_any_delimiter(&self) -> Result<(Delimiter, DelimSpan, ParseBuffer)>;
+}
+
+impl<'a> AnyDelimiter for ParseBuffer<'a> {
+    fn parse_any_delimiter(&self) -> Result<(Delimiter, DelimSpan, ParseBuffer)> {
+        self.step(|cursor| {
+            if let Some((content, delimiter, span, rest)) = cursor.any_group() {
+                let scope = crate::buffer::close_span_of_group(*cursor);
+                let nested = crate::parse::advance_step_cursor(cursor, content);
+                let unexpected = crate::parse::get_unexpected(self);
+                let content = crate::parse::new_parse_buffer(scope, nested, unexpected);
+                Ok(((delimiter, span, content), rest))
+            } else {
+                Err(cursor.error("expected any delimiter"))
+            }
+        })
+    }
+}