Make MetaMethod::name() public

Tests for UserDataMetatable::pairs()

Author: khvzak

src/userdata.rs

@@ -135,7 +135,8 @@ impl fmt::Display for MetaMethod {
 }
 
 impl MetaMethod {
-    pub(crate) fn name(&self) -> &str {
+    /// Returns Lua metamethod name, usually prefixed by two underscores.
+    pub fn name(&self) -> &str {
         match self {
             MetaMethod::Add => "__add",
             MetaMethod::Sub => "__sub",
@@ -871,7 +872,7 @@ impl<'lua> UserDataMetatable<'lua> {
     /// The pairs are wrapped in a [`Result`], since they are lazily converted to `V` type.
     ///
     /// [`Result`]: type.Result.html
-    pub fn pairs<K: FromLua<'lua>, V: FromLua<'lua>>(self) -> UserDataMetatablePairs<'lua, V> {
+    pub fn pairs<V: FromLua<'lua>>(self) -> UserDataMetatablePairs<'lua, V> {
         UserDataMetatablePairs(self.0.pairs())
     }
 }

tests/userdata.rs

@@ -428,6 +428,14 @@ fn test_metatable() -> Result<()> {
         Err(e) => panic!("expected MetaMethodRestricted, got {:?}", e),
     }
 
+    let mut methods = metatable
+        .pairs()
+        .into_iter()
+        .map(|kv: Result<(_, Value)>| Ok(kv?.0))
+        .collect::<Result<Vec<_>>>()?;
+    methods.sort_by_cached_key(|k| k.name().to_owned());
+    assert_eq!(methods, vec![MetaMethod::Index, "__type_name".into()]);
+
     #[derive(Copy, Clone)]
     struct MyUserData2(i64);