Implement Default for MapChain

2 files changed, 10 insertions, 8 deletions

diff --git a/askama_derive/src/generator.rs b/askama_derive/src/generator.rs
index 74d1869..8d120be 100644
--- a/askama_derive/src/generator.rs
+++ b/askama_derive/src/generator.rs
@@ -1775,13 +1775,6 @@ impl<'a, K: 'a, V: 'a> MapChain<'a, K, V>
 where
     K: cmp::Eq + hash::Hash,
 {
-    pub(crate) fn new() -> MapChain<'a, K, V> {
-        MapChain {
-            parent: None,
-            scopes: vec![HashMap::new()],
-        }
-    }
-
     fn with_parent<'p>(parent: &'p MapChain<'_, K, V>) -> MapChain<'p, K, V> {
         MapChain {
             parent: Some(parent),
@@ -1844,6 +1837,15 @@ impl MapChain<'_, &str, LocalMeta> {
     }
 }
 
+impl<'a, K: Eq + hash::Hash, V> Default for MapChain<'a, K, V> {
+    fn default() -> Self {
+        Self {
+            parent: None,
+            scopes: vec![HashMap::new()],
+        }
+    }
+}
+
 /// Returns `true` if enough assumptions can be made,
 /// to determine that `self` is copyable.
 fn is_copyable(expr: &Expr<'_>) -> bool {
diff --git a/askama_derive/src/lib.rs b/askama_derive/src/lib.rs
index dc8ca75..37e8a3b 100644
--- a/askama_derive/src/lib.rs
+++ b/askama_derive/src/lib.rs
@@ -70,7 +70,7 @@ pub(crate) fn build_template(ast: &syn::DeriveInput) -> Result<String, CompileEr
         &input,
         &contexts,
         heritage.as_ref(),
-        MapChain::new(),
+        MapChain::default(),
         config.whitespace,
     )
     .build(&contexts[input.path.as_path()])?;