1 files changed, 34 insertions, 0 deletions
diff --git a/vendor/syn/src/gen_helper.rs b/vendor/syn/src/gen_helper.rs
new file mode 100644
index 0000000..e433bac
--- /dev/null
+++ b/vendor/syn/src/gen_helper.rs
@@ -0,0 +1,34 @@
+#[cfg(feature = "fold")]
+pub(crate) mod fold {
+    use crate::punctuated::{Pair, Punctuated};
+
+    pub(crate) trait FoldHelper {
+        type Item;
+        fn lift<F>(self, f: F) -> Self
+        where
+            F: FnMut(Self::Item) -> Self::Item;
+    }
+
+    impl<T> FoldHelper for Vec<T> {
+        type Item = T;
+        fn lift<F>(self, f: F) -> Self
+        where
+            F: FnMut(Self::Item) -> Self::Item,
+        {
+            self.into_iter().map(f).collect()
+        }
+    }
+
+    impl<T, U> FoldHelper for Punctuated<T, U> {
+        type Item = T;
+        fn lift<F>(self, mut f: F) -> Self
+        where
+            F: FnMut(Self::Item) -> Self::Item,
+        {
+            self.into_pairs()
+                .map(Pair::into_tuple)
+                .map(|(t, u)| Pair::new(f(t), u))
+                .collect()
+        }
+    }
+}