API changes, inline more often

Refactor existing implementation and add 4-dimensional vectors support.

.github/workflows/main.yml

@@ -9,7 +9,7 @@ jobs:
       matrix:
         os: [ubuntu-22.04, macos-latest, windows-latest]
         rust: [stable]
-        lua: [lua54, lua53, lua52, lua51, luajit, luau, luau-jit]
+        lua: [lua54, lua53, lua52, lua51, luajit, luau, luau-jit, luau-vector4]
         include:
           - os: ubuntu-22.04
             target: x86_64-unknown-linux-gnu
@@ -104,7 +104,7 @@ jobs:
       matrix:
         os: [ubuntu-22.04, macos-latest, windows-latest]
         rust: [stable, nightly]
-        lua: [lua54, lua53, lua52, lua51, luajit, luajit52, luau, luau-jit]
+        lua: [lua54, lua53, lua52, lua51, luajit, luajit52, luau, luau-jit, luau-vector4]
         include:
           - os: ubuntu-22.04
             target: x86_64-unknown-linux-gnu
@@ -140,7 +140,7 @@ jobs:
       matrix:
         os: [ubuntu-22.04]
         rust: [nightly]
-        lua: [lua54, lua53, lua52, lua51, luajit, luau, luau-jit]
+        lua: [lua54, lua53, lua52, lua51, luajit, luau, luau-jit, luau-vector4]
         include:
           - os: ubuntu-22.04
             target: x86_64-unknown-linux-gnu
@@ -222,7 +222,7 @@ jobs:
     runs-on: ubuntu-22.04
     strategy:
       matrix:
-        lua: [lua54, lua53, lua52, lua51, luajit, luau, luau-jit]
+        lua: [lua54, lua53, lua52, lua51, luajit, luau, luau-jit, luau-vector4]
     steps:
       - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@stable

Cargo.toml

@@ -33,6 +33,7 @@ luajit = ["ffi/luajit"]
 luajit52 = ["luajit", "ffi/luajit52"]
 luau = ["ffi/luau"]
 luau-jit = ["luau", "ffi/luau-codegen"]
+luau-vector4 = ["luau", "ffi/luau-vector4"]
 vendored = ["ffi/vendored"]
 module = ["mlua_derive", "ffi/module"]
 async = ["futures-util"]

README.md

@@ -46,6 +46,7 @@ Below is a list of the available feature flags. By default `mlua` does not enabl
 * `luajit52`: activate [LuaJIT] support with partial compatibility with Lua 5.2
 * `luau`: activate [Luau] support (auto vendored mode)
 * `luau-jit`: activate [Luau] support with experimental jit backend. This is unstable feature and not recommended to use.
+* `luau-vector4`: activate [Luau] support with 4-dimensional vector.
 * `vendored`: build static Lua(JIT) library from sources during `mlua` compilation using [lua-src] or [luajit-src] crates
 * `module`: enable module mode (building loadable `cdylib` library for Lua)
 * `async`: enable async/await support (any executor can be used, eg. [tokio] or [async-std])

benches/benchmark.rs

@@ -264,17 +264,19 @@ fn call_userdata_method(c: &mut Criterion) {
 }
 
 fn call_async_userdata_method(c: &mut Criterion) {
-    #[derive(Clone, Copy)]
-    struct UserData(i64);
+    struct UserData(String);
+
     impl LuaUserData for UserData {
         fn add_methods<'lua, M: LuaUserDataMethods<'lua, Self>>(methods: &mut M) {
-            methods.add_async_method("method", |_, this, ()| async move { Ok(this.0) });
+            methods.add_async_method("method", |_, this, ()| async move { Ok(this.0.clone()) });
         }
     }
 
     let options = LuaOptions::new().thread_pool_size(1024);
     let lua = Lua::new_with(LuaStdLib::ALL_SAFE, options).unwrap();
-    lua.globals().set("userdata", UserData(10)).unwrap();
+    lua.globals()
+        .set("userdata", UserData("hello".to_string()))
+        .unwrap();
 
     c.bench_function("call async [userdata method] 10", |b| {
         let rt = Runtime::new().unwrap();

examples/async_http_client.rs

@@ -3,14 +3,13 @@ use std::collections::HashMap;
 use hyper::body::{Body as HyperBody, HttpBody as _};
 use hyper::Client as HyperClient;
 
-use mlua::{chunk, AnyUserData, ExternalResult, Lua, Result, UserData, UserDataMethods};
+use mlua::{chunk, ExternalResult, Lua, Result, UserData, UserDataMethods};
 
 struct BodyReader(HyperBody);
 
 impl UserData for BodyReader {
     fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
-        methods.add_async_function("read", |lua, reader: AnyUserData| async move {
-            let mut reader = reader.borrow_mut::<Self>()?;
+        methods.add_async_method_mut("read", |lua, reader, ()| async move {
             if let Some(bytes) = reader.0.data().await {
                 let bytes = bytes.into_lua_err()?;
                 return Some(lua.create_string(&bytes)).transpose();

examples/async_tcp_server.rs

@@ -6,9 +6,7 @@ use tokio::io::{AsyncReadExt, AsyncWriteExt};
 use tokio::net::{TcpListener, TcpStream};
 use tokio::task;
 
-use mlua::{
-    chunk, AnyUserData, Function, Lua, RegistryKey, String as LuaString, UserData, UserDataMethods,
-};
+use mlua::{chunk, Function, Lua, RegistryKey, String as LuaString, UserData, UserDataMethods};
 
 struct LuaTcpStream(TcpStream);
 
@@ -18,28 +16,19 @@ impl UserData for LuaTcpStream {
             Ok(this.0.peer_addr()?.to_string())
         });
 
-        methods.add_async_function(
-            "read",
-            |lua, (this, size): (AnyUserData, usize)| async move {
-                let mut this = this.borrow_mut::<Self>()?;
-                let mut buf = vec![0; size];
-                let n = this.0.read(&mut buf).await?;
-                buf.truncate(n);
-                lua.create_string(&buf)
-            },
-        );
+        methods.add_async_method_mut("read", |lua, this, size| async move {
+            let mut buf = vec![0; size];
+            let n = this.0.read(&mut buf).await?;
+            buf.truncate(n);
+            lua.create_string(&buf)
+        });
 
-        methods.add_async_function(
-            "write",
-            |_, (this, data): (AnyUserData, LuaString)| async move {
-                let mut this = this.borrow_mut::<Self>()?;
-                let n = this.0.write(&data.as_bytes()).await?;
-                Ok(n)
-            },
-        );
+        methods.add_async_method_mut("write", |_, this, data: LuaString| async move {
+            let n = this.0.write(&data.as_bytes()).await?;
+            Ok(n)
+        });
 
-        methods.add_async_function("close", |_, this: AnyUserData| async move {
-            let mut this = this.borrow_mut::<Self>()?;
+        methods.add_async_method_mut("close", |_, this, ()| async move {
             this.0.shutdown().await?;
             Ok(())
         });

mlua-sys/Cargo.toml

@@ -27,6 +27,7 @@ luajit = []
 luajit52 = ["luajit"]
 luau = ["luau0-src"]
 luau-codegen = ["luau"]
+luau-vector4 = ["luau"]
 vendored = ["lua-src", "luajit-src"]
 module = []
 
@@ -38,4 +39,4 @@ cfg-if = "1.0"
 pkg-config = "0.3.17"
 lua-src = { version = ">= 546.0.0, < 550.0.0", optional = true }
 luajit-src = { version = ">= 210.4.0, < 220.0.0", optional = true }
-luau0-src = { version = "0.5.8", optional = true }
+luau0-src = { version = "0.5.10", optional = true }

mlua-sys/build/find_normal.rs

@@ -1,5 +1,3 @@
-#![allow(dead_code)]
-
 use std::env;
 use std::ops::Bound;
 use std::path::PathBuf;

mlua-sys/build/find_vendored.rs

@@ -1,5 +1,3 @@
-#![allow(dead_code)]
-
 use std::path::PathBuf;
 
 pub fn probe_lua() -> Option<PathBuf> {
@@ -23,6 +21,7 @@ pub fn probe_lua() -> Option<PathBuf> {
     #[cfg(feature = "luau")]
     let artifacts = luau0_src::Build::new()
         .enable_codegen(cfg!(feature = "luau-codegen"))
+        .set_vector_size(if cfg!(feature = "luau-vector4") { 4 } else { 3 })
         .build();
 
     artifacts.print_cargo_metadata();

mlua-sys/src/luau/compat.rs

@@ -397,6 +397,7 @@ pub unsafe fn luaL_len(L: *mut lua_State, idx: c_int) -> lua_Integer {
     res
 }
 
+// TODO: why not just checkstack and concat all at the end?
 pub unsafe fn luaL_traceback(
     L: *mut lua_State,
     L1: *mut lua_State,

mlua-sys/src/luau/lua.rs

@@ -156,7 +156,10 @@ extern "C" {
     pub fn lua_pushnumber(L: *mut lua_State, n: lua_Number);
     pub fn lua_pushinteger(L: *mut lua_State, n: lua_Integer);
     pub fn lua_pushunsigned(L: *mut lua_State, n: lua_Unsigned);
+    #[cfg(not(feature = "luau-vector4"))]
     pub fn lua_pushvector(L: *mut lua_State, x: c_float, y: c_float, z: c_float);
+    #[cfg(feature = "luau-vector4")]
+    pub fn lua_pushvector(L: *mut lua_State, x: c_float, y: c_float, z: c_float, w: c_float);
     #[link_name = "lua_pushlstring"]
     pub fn lua_pushlstring_(L: *mut lua_State, s: *const c_char, l: usize);
     #[link_name = "lua_pushstring"]

src/chunk.rs

@@ -11,9 +11,6 @@ use crate::lua::Lua;
 use crate::table::Table;
 use crate::value::{FromLuaMulti, IntoLua, IntoLuaMulti};
 
-#[cfg(feature = "async")]
-use futures_util::future::{self, LocalBoxFuture};
-
 /// Trait for types [loadable by Lua] and convertible to a [`Chunk`]
 ///
 /// [loadable by Lua]: https://www.lua.org/manual/5.4/manual.html#3.3.2
@@ -312,8 +309,8 @@ impl<'lua, 'a> Chunk<'lua, 'a> {
     /// [`exec`]: #method.exec
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    pub fn exec_async(self) -> LocalBoxFuture<'lua, Result<()>> {
-        self.call_async(())
+    pub async fn exec_async(self) -> Result<()> {
+        self.call_async(()).await
     }
 
     /// Evaluate the chunk as either an expression or block.
@@ -344,17 +341,16 @@ impl<'lua, 'a> Chunk<'lua, 'a> {
     /// [`eval`]: #method.eval
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    pub fn eval_async<'fut, R>(self) -> LocalBoxFuture<'fut, Result<R>>
+    pub async fn eval_async<R>(self) -> Result<R>
     where
-        'lua: 'fut,
-        R: FromLuaMulti<'lua> + 'fut,
+        R: FromLuaMulti<'lua> + 'lua,
     {
         if self.detect_mode() == ChunkMode::Binary {
-            self.call_async(())
+            self.call_async(()).await
         } else if let Ok(function) = self.to_expression() {
-            function.call_async(())
+            function.call_async(()).await
         } else {
-            self.call_async(())
+            self.call_async(()).await
         }
     }
 
@@ -374,16 +370,12 @@ impl<'lua, 'a> Chunk<'lua, 'a> {
     /// [`call`]: #method.call
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    pub fn call_async<'fut, A, R>(self, args: A) -> LocalBoxFuture<'fut, Result<R>>
+    pub async fn call_async<A, R>(self, args: A) -> Result<R>
     where
-        'lua: 'fut,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut,
+        R: FromLuaMulti<'lua> + 'lua,
     {
-        match self.into_function() {
-            Ok(func) => func.call_async(args),
-            Err(e) => Box::pin(future::err(e)),
-        }
+        self.into_function()?.call_async(args).await
     }
 
     /// Load this chunk into a regular `Function`.

src/conversion.rs

@@ -38,30 +38,45 @@ impl<'lua> FromLua<'lua> for Value<'lua> {
     }
 }
 
+impl<'lua> From<String<'lua>> for Value<'lua> {
+    #[inline]
+    fn from(value: String<'lua>) -> Self {
+        Value::String(value)
+    }
+}
+
 impl<'lua> IntoLua<'lua> for String<'lua> {
     #[inline]
     fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
-        Ok(Value::String(self))
+        Ok(self.into())
     }
 }
 
 impl<'lua> FromLua<'lua> for String<'lua> {
     #[inline]
-    fn from_lua(value: Value<'lua>, lua: &'lua Lua) -> Result<String<'lua>> {
-        let ty = value.type_name();
-        lua.coerce_string(value)?
-            .ok_or_else(|| Error::FromLuaConversionError {
-                from: ty,
-                to: "String",
-                message: Some("expected string or number".to_string()),
+    fn from_lua(value: Value<'lua>, _: &'lua Lua) -> Result<String<'lua>> {
+        match value {
+            Value::String(s) => Ok(s),
+            _ => Err(Error::FromLuaConversionError {
+                from: value.type_name(),
+                to: "string",
+                message: None,
             })
+        }
+    }
+}
+
+impl<'lua> From<Table<'lua>> for Value<'lua> {
+    #[inline]
+    fn from(value: Table<'lua>) -> Self {
+        Value::Table(value)
     }
 }
 
 impl<'lua> IntoLua<'lua> for Table<'lua> {
     #[inline]
     fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
-        Ok(Value::Table(self))
+        Ok(self.into())
     }
 }
 
@@ -97,10 +112,17 @@ impl<'lua> FromLua<'lua> for OwnedTable {
     }
 }
 
+impl<'lua> From<Function<'lua>> for Value<'lua> {
+    #[inline]
+    fn from(value: Function<'lua>) -> Self {
+        Value::Function(value)
+    }
+}
+
 impl<'lua> IntoLua<'lua> for Function<'lua> {
     #[inline]
     fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
-        Ok(Value::Function(self))
+        Ok(self.into())
     }
 }
 
@@ -151,10 +173,17 @@ impl<'lua> IntoLua<'lua> for WrappedAsyncFunction<'lua> {
     }
 }
 
+impl<'lua> From<Thread<'lua>> for Value<'lua> {
+    #[inline]
+    fn from(value: Thread<'lua>) -> Self {
+        Value::Thread(value)
+    }
+}
+
 impl<'lua> IntoLua<'lua> for Thread<'lua> {
     #[inline]
     fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
-        Ok(Value::Thread(self))
+        Ok(self.into())
     }
 }
 
@@ -172,10 +201,17 @@ impl<'lua> FromLua<'lua> for Thread<'lua> {
     }
 }
 
+impl<'lua> From<AnyUserData<'lua>> for Value<'lua> {
+    #[inline]
+    fn from(value: AnyUserData<'lua>) -> Self {
+        Value::UserData(value)
+    }
+}
+
 impl<'lua> IntoLua<'lua> for AnyUserData<'lua> {
     #[inline]
     fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
-        Ok(Value::UserData(self))
+        Ok(self.into())
     }
 }
 
@@ -232,49 +268,67 @@ impl<'lua, T: 'static> FromLua<'lua> for UserDataRefMut<'lua, T> {
     }
 }
 
+impl<'lua> From<Error> for Value<'lua> {
+    #[inline]
+    fn from(value: Error) -> Self {
+        Value::Error(value)
+    }
+}
+
 impl<'lua> IntoLua<'lua> for Error {
     #[inline]
     fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
-        Ok(Value::Error(self))
+        Ok(self.into())
     }
 }
 
 impl<'lua> FromLua<'lua> for Error {
     #[inline]
-    fn from_lua(value: Value<'lua>, lua: &'lua Lua) -> Result<Error> {
+    fn from_lua(value: Value<'lua>, _: &'lua Lua) -> Result<Error> {
         match value {
             Value::Error(err) => Ok(err),
-            val => Ok(Error::RuntimeError(
-                lua.coerce_string(val)?
-                    .and_then(|s| Some(s.to_str().ok()?.to_owned()))
-                    .unwrap_or_else(|| "<unprintable error>".to_owned()),
-            )),
+            _ => Err(Error::FromLuaConversionError { from: value.type_name(), to: "error", message: None }),
         }
     }
 }
 
+impl<'lua> From<bool> for Value<'lua> {
+    #[inline]
+    fn from(value: bool) -> Self {
+        Value::Boolean(value)
+    }
+}
+
 impl<'lua> IntoLua<'lua> for bool {
     #[inline]
     fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
-        Ok(Value::Boolean(self))
+        Ok(self.into())
     }
 }
 
 impl<'lua> FromLua<'lua> for bool {
     #[inline]
-    fn from_lua(v: Value<'lua>, _: &'lua Lua) -> Result<Self> {
-        match v {
+    fn from_lua(value: Value<'lua>, _: &'lua Lua) -> Result<Self> {
+        match value {
             Value::Nil => Ok(false),
             Value::Boolean(b) => Ok(b),
-            _ => Ok(true),
+            _ => Err(Error::FromLuaConversionError { from: value.type_name(), to: "boolean", message: None }),
         }
     }
 }
 
+impl<'lua> From<LightUserData> for Value<'lua> {
+    #[inline]
+    fn from(value: LightUserData) -> Self {
+        Value::LightUserData(value)
+    }
+}
+
+
 impl<'lua> IntoLua<'lua> for LightUserData {
     #[inline]
     fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
-        Ok(Value::LightUserData(self))
+        Ok(self.into())
     }
 }
 
@@ -292,6 +346,38 @@ impl<'lua> FromLua<'lua> for LightUserData {
     }
 }
 
+#[cfg(feature = "luau")]
+impl<'lua> From<crate::types::Vector> for Value<'lua> {
+    #[inline]
+    fn from(value: crate::types::Vector) -> Self {
+        Value::Vector(value)
+    }
+}
+
+
+#[cfg(feature = "luau")]
+impl<'lua> IntoLua<'lua> for crate::types::Vector {
+    #[inline]
+    fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
+        Ok(Value::Vector(self))
+    }
+}
+
+#[cfg(feature = "luau")]
+impl<'lua> FromLua<'lua> for crate::types::Vector {
+    #[inline]
+    fn from_lua(value: Value<'lua>, _: &'lua Lua) -> Result<Self> {
+        match value {
+            Value::Vector(v) => Ok(v),
+            _ => Err(Error::FromLuaConversionError {
+                from: value.type_name(),
+                to: "vector",
+                message: None,
+            }),
+        }
+    }
+}
+
 impl<'lua> IntoLua<'lua> for StdString {
     #[inline]
     fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
@@ -302,16 +388,8 @@ impl<'lua> IntoLua<'lua> for StdString {
 impl<'lua> FromLua<'lua> for StdString {
     #[inline]
     fn from_lua(value: Value<'lua>, lua: &'lua Lua) -> Result<Self> {
-        let ty = value.type_name();
-        Ok(lua
-            .coerce_string(value)?
-            .ok_or_else(|| Error::FromLuaConversionError {
-                from: ty,
-                to: "String",
-                message: Some("expected string or number".to_string()),
-            })?
-            .to_str()?
-            .to_owned())
+        let s = String::from_lua(value, lua)?;
+        Ok(s.to_str()?.to_owned())
     }
 }
 
@@ -339,17 +417,7 @@ impl<'lua> IntoLua<'lua> for Box<str> {
 impl<'lua> FromLua<'lua> for Box<str> {
     #[inline]
     fn from_lua(value: Value<'lua>, lua: &'lua Lua) -> Result<Self> {
-        let ty = value.type_name();
-        Ok(lua
-            .coerce_string(value)?
-            .ok_or_else(|| Error::FromLuaConversionError {
-                from: ty,
-                to: "Box<str>",
-                message: Some("expected string or number".to_string()),
-            })?
-            .to_str()?
-            .to_owned()
-            .into_boxed_str())
+        StdString::from_lua(value, lua).map(|s| s.into_boxed_str())
     }
 }
 
@@ -363,23 +431,15 @@ impl<'lua> IntoLua<'lua> for CString {
 impl<'lua> FromLua<'lua> for CString {
     #[inline]
     fn from_lua(value: Value<'lua>, lua: &'lua Lua) -> Result<Self> {
-        let ty = value.type_name();
-        let string = lua
-            .coerce_string(value)?
-            .ok_or_else(|| Error::FromLuaConversionError {
-                from: ty,
+        let s = String::from_lua(value, lua)?;
+        match CStr::from_bytes_with_nul(s.as_bytes_with_nul()) {
+            Ok(s) => Ok(s.to_owned()),
+            Err(e) => Err(Error::FromLuaConversionError {
+                from: "string",
                 to: "CString",
-                message: Some("expected string or number".to_string()),
-            })?;
-
-        match CStr::from_bytes_with_nul(string.as_bytes_with_nul()) {
-            Ok(s) => Ok(s.into()),
-            Err(_) => Err(Error::FromLuaConversionError {
-                from: ty,
-                to: "CString",
-                message: Some("invalid C-style string".to_string()),
+                message: Some(e.to_string()),
             }),
-        }
+        } 
     }
 }
 
@@ -407,17 +467,8 @@ impl<'lua> IntoLua<'lua> for BString {
 impl<'lua> FromLua<'lua> for BString {
     #[inline]
     fn from_lua(value: Value<'lua>, lua: &'lua Lua) -> Result<Self> {
-        let ty = value.type_name();
-        Ok(BString::from(
-            lua.coerce_string(value)?
-                .ok_or_else(|| Error::FromLuaConversionError {
-                    from: ty,
-                    to: "String",
-                    message: Some("expected string or number".to_string()),
-                })?
-                .as_bytes()
-                .to_vec(),
-        ))
+        let s = String::from_lua(value, lua)?;
+        Ok(BString::from(s.as_bytes().to_vec()))
     }
 }
 
@@ -428,9 +479,20 @@ impl<'lua> IntoLua<'lua> for &BStr {
     }
 }
 
+macro_rules! lua_convert_int_infallible {
+    ($($x:ty),*) => {
+        $(impl<'lua> From<$x> for Value<'lua> {
+            #[inline]
+            fn from(value: $x) -> Self {
+                Self::Integer(value.into())
+            }
+        })*
+    }
+}
+
 macro_rules! lua_convert_int {
-    ($x:ty) => {
-        impl<'lua> IntoLua<'lua> for $x {
+    ($($x:ty),*) => {
+        $(impl<'lua> IntoLua<'lua> for $x {
             #[inline]
             fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
                 cast(self)
@@ -447,53 +509,32 @@ macro_rules! lua_convert_int {
 
         impl<'lua> FromLua<'lua> for $x {
             #[inline]
-            fn from_lua(value: Value<'lua>, lua: &'lua Lua) -> Result<Self> {
-                let ty = value.type_name();
+            fn from_lua(value: Value<'lua>, _: &'lua Lua) -> Result<Self> {
                 (match value {
                     Value::Integer(i) => cast(i),
                     Value::Number(n) => cast(n),
-                    _ => {
-                        if let Some(i) = lua.coerce_integer(value.clone())? {
-                            cast(i)
-                        } else {
-                            cast(lua.coerce_number(value)?.ok_or_else(|| {
-                                Error::FromLuaConversionError {
-                                    from: ty,
-                                    to: stringify!($x),
-                                    message: Some(
-                                        "expected number or string coercible to number".to_string(),
-                                    ),
-                                }
-                            })?)
-                        }
-                    }
+                    _ => return Err(Error::FromLuaConversionError {
+                        from: value.type_name(),
+                        to: stringify!($x),
+                        message: None,
+                    }),
                 })
                 .ok_or_else(|| Error::FromLuaConversionError {
-                    from: ty,
+                    from: value.type_name(),
                     to: stringify!($x),
                     message: Some("out of range".to_owned()),
                 })
             }
-        }
+        })*
     };
 }
 
-lua_convert_int!(i8);
-lua_convert_int!(u8);
-lua_convert_int!(i16);
-lua_convert_int!(u16);
-lua_convert_int!(i32);
-lua_convert_int!(u32);
-lua_convert_int!(i64);
-lua_convert_int!(u64);
-lua_convert_int!(i128);
-lua_convert_int!(u128);
-lua_convert_int!(isize);
-lua_convert_int!(usize);
+lua_convert_int!(i8, u8, i16, u16, i32, u32, i64, u64, i128, u128, isize, usize);
+lua_convert_int_infallible!(i8, u8, i16, u16, i32);
 
 macro_rules! lua_convert_float {
-    ($x:ty) => {
-        impl<'lua> IntoLua<'lua> for $x {
+    ($($x:ty),*) => {
+        $(impl<'lua> IntoLua<'lua> for $x {
             #[inline]
             fn into_lua(self, _: &'lua Lua) -> Result<Value<'lua>> {
                 cast(self)
@@ -508,28 +549,27 @@ macro_rules! lua_convert_float {
 
         impl<'lua> FromLua<'lua> for $x {
             #[inline]
-            fn from_lua(value: Value<'lua>, lua: &'lua Lua) -> Result<Self> {
-                let ty = value.type_name();
-                lua.coerce_number(value)?
-                    .ok_or_else(|| Error::FromLuaConversionError {
-                        from: ty,
+            fn from_lua(value: Value<'lua>, _: &'lua Lua) -> Result<Self> {
+                (match value {
+                    Value::Integer(i) => cast(i),
+                    Value::Number(n) => cast(n),
+                    _ => return Err(Error::FromLuaConversionError {
+                        from: value.type_name(),
                         to: stringify!($x),
-                        message: Some("expected number or string coercible to number".to_string()),
-                    })
-                    .and_then(|n| {
-                        cast(n).ok_or_else(|| Error::FromLuaConversionError {
-                            from: ty,
-                            to: stringify!($x),
-                            message: Some("number out of range".to_string()),
-                        })
-                    })
+                        message: None,
+                    }),
+                })
+                .ok_or_else(|| Error::FromLuaConversionError {
+                    from: value.type_name(),
+                    to: stringify!($x),
+                    message: Some("out of range".to_owned()),
+                })
             }
-        }
+        })*
     };
 }
 
-lua_convert_float!(f32);
-lua_convert_float!(f64);
+lua_convert_float!(f32, f64);
 
 impl<'lua, T> IntoLua<'lua> for &[T]
 where
@@ -561,16 +601,17 @@ where
     fn from_lua(value: Value<'lua>, _lua: &'lua Lua) -> Result<Self> {
         match value {
             #[cfg(feature = "luau")]
-            Value::Vector(x, y, z) if N == 3 => Ok(mlua_expect!(
-                vec![
-                    T::from_lua(Value::Number(x as _), _lua)?,
-                    T::from_lua(Value::Number(y as _), _lua)?,
-                    T::from_lua(Value::Number(z as _), _lua)?,
-                ]
-                .try_into()
-                .map_err(|_| ()),
-                "cannot convert vector to array"
-            )),
+            #[rustfmt::skip]
+            Value::Vector(v) if N == crate::types::Vector::SIZE => unsafe {
+                use std::{mem, ptr};
+                let mut arr: [mem::MaybeUninit<T>; N] = mem::MaybeUninit::uninit().assume_init();
+                ptr::write(arr[0].as_mut_ptr() , T::from_lua(Value::Number(v.x() as _), _lua)?);
+                ptr::write(arr[1].as_mut_ptr(), T::from_lua(Value::Number(v.y() as _), _lua)?);
+                ptr::write(arr[2].as_mut_ptr(), T::from_lua(Value::Number(v.z() as _), _lua)?);
+                #[cfg(feature = "luau-vector4")]
+                ptr::write(arr[3].as_mut_ptr(), T::from_lua(Value::Number(v.w() as _), _lua)?);
+                Ok(mem::transmute_copy(&arr))
+            },
             Value::Table(table) => {
                 let vec = table.sequence_values().collect::<Result<Vec<_>>>()?;
                 vec.try_into()
@@ -614,12 +655,6 @@ impl<'lua, T: FromLua<'lua>> FromLua<'lua> for Vec<T> {
     #[inline]
     fn from_lua(value: Value<'lua>, _lua: &'lua Lua) -> Result<Self> {
         match value {
-            #[cfg(feature = "luau")]
-            Value::Vector(x, y, z) => Ok(vec![
-                T::from_lua(Value::Number(x as _), _lua)?,
-                T::from_lua(Value::Number(y as _), _lua)?,
-                T::from_lua(Value::Number(z as _), _lua)?,
-            ]),
             Value::Table(table) => table.sequence_values().collect(),
             _ => Err(Error::FromLuaConversionError {
                 from: value.type_name(),

src/error.rs

@@ -130,7 +130,7 @@ pub enum Error {
     ///
     /// [`AnyUserData`]: crate::AnyUserData
     UserDataDestructed,
-    /// An [`AnyUserData`] immutable borrow failed because it is already borrowed mutably.
+    /// An [`AnyUserData`] immutable borrow failed.
     ///
     /// This error can occur when a method on a [`UserData`] type calls back into Lua, which then
     /// tries to call a method on the same [`UserData`] type. Consider restructuring your API to
@@ -139,7 +139,7 @@ pub enum Error {
     /// [`AnyUserData`]: crate::AnyUserData
     /// [`UserData`]: crate::UserData
     UserDataBorrowError,
-    /// An [`AnyUserData`] mutable borrow failed because it is already borrowed.
+    /// An [`AnyUserData`] mutable borrow failed.
     ///
     /// This error can occur when a method on a [`UserData`] type calls back into Lua, which then
     /// tries to call a method on the same [`UserData`] type. Consider restructuring your API to
@@ -270,8 +270,8 @@ impl fmt::Display for Error {
             Error::CoroutineInactive => write!(fmt, "cannot resume inactive coroutine"),
             Error::UserDataTypeMismatch => write!(fmt, "userdata is not expected type"),
             Error::UserDataDestructed => write!(fmt, "userdata has been destructed"),
-            Error::UserDataBorrowError => write!(fmt, "userdata already mutably borrowed"),
-            Error::UserDataBorrowMutError => write!(fmt, "userdata already borrowed"),
+            Error::UserDataBorrowError => write!(fmt, "error borrowing userdata"),
+            Error::UserDataBorrowMutError => write!(fmt, "error mutably borrowing userdata"),
             Error::MetaMethodRestricted(ref method) => write!(fmt, "metamethod {method} is restricted"),
             Error::MetaMethodTypeError { ref method, type_name, ref message } => {
                 write!(fmt, "metamethod {method} has unsupported type {type_name}")?;

src/ffi.rs

@@ -0,0 +1,8 @@
+pub use ::ffi::*;
+
+use crate::util::{push_gc_userdata, WrappedFailure};
+
+#[inline]
+pub unsafe fn mlua_pusherror(state: *mut lua_State, err: crate::Error) -> crate::Result<()> {
+    push_gc_userdata(state, WrappedFailure::Error(err), false)
+}

src/function.rs

@@ -17,7 +17,7 @@ use crate::value::{FromLuaMulti, IntoLua, IntoLuaMulti};
 #[cfg(feature = "async")]
 use {
     crate::types::AsyncCallback,
-    futures_util::future::{self, Future, LocalBoxFuture, TryFutureExt},
+    futures_util::future::{self, Future},
 };
 
 /// Handle to an internal Lua function.
@@ -77,13 +77,17 @@ pub struct FunctionInfo {
 #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct CoverageInfo {
-    pub function: Option<std::string::String>,
+    pub function: Option<String>,
     pub line_defined: i32,
     pub depth: i32,
     pub hits: Vec<i32>,
 }
 
 impl<'lua> Function<'lua> {
+    pub fn as_raw_ref(&self) -> &LuaRef<'lua> {
+        &self.0
+    }
+
     /// Calls the function, passing `args` as function arguments.
     ///
     /// The function's return values are converted to the generic type `R`.
@@ -188,21 +192,18 @@ impl<'lua> Function<'lua> {
     /// [`AsyncThread`]: crate::AsyncThread
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    pub fn call_async<'fut, A, R>(&self, args: A) -> LocalBoxFuture<'fut, Result<R>>
+    pub fn call_async<A, R>(&self, args: A) -> impl Future<Output = Result<R>> + 'lua
     where
-        'lua: 'fut,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut,
+        R: FromLuaMulti<'lua> + 'lua,
     {
         let lua = self.0.lua;
-        match lua.create_recycled_thread(self) {
-            Ok(t) => {
-                let mut t = t.into_async(args);
-                t.set_recyclable(true);
-                Box::pin(t)
-            }
-            Err(e) => Box::pin(future::err(e)),
-        }
+        let thread_res = lua.create_recycled_thread(self).map(|th| {
+            let mut th = th.into_async(args);
+            th.set_recyclable(true);
+            th
+        });
+        async move { thread_res?.await }
     }
 
     /// Returns a function that, when called, calls `self`, passing `args` as the first set of
@@ -303,17 +304,7 @@ impl<'lua> Function<'lua> {
             assert_stack(state, 1);
 
             lua.push_ref(&self.0);
-
-            let mut ar: ffi::lua_Debug = mem::zeroed();
-            #[cfg(not(feature = "luau"))]
-            {
-                ffi::lua_pushvalue(state, -1);
-                ffi::lua_getinfo(state, cstr!(">S"), &mut ar);
-            }
-            #[cfg(feature = "luau")]
-            ffi::lua_getinfo(state, -1, cstr!("s"), &mut ar);
-
-            if ptr_to_cstr_bytes(ar.what) == Some(b"C") {
+            if ffi::lua_iscfunction(state, -1) != 0 {
                 return None;
             }
 
@@ -350,17 +341,7 @@ impl<'lua> Function<'lua> {
             check_stack(state, 2)?;
 
             lua.push_ref(&self.0);
-
-            let mut ar: ffi::lua_Debug = mem::zeroed();
-            #[cfg(not(feature = "luau"))]
-            {
-                ffi::lua_pushvalue(state, -1);
-                ffi::lua_getinfo(state, cstr!(">S"), &mut ar);
-            }
-            #[cfg(feature = "luau")]
-            ffi::lua_getinfo(state, -1, cstr!("s"), &mut ar);
-
-            if ptr_to_cstr_bytes(ar.what) == Some(b"C") {
+            if ffi::lua_iscfunction(state, -1) != 0 {
                 return Ok(false);
             }
 
@@ -564,12 +545,12 @@ impl OwnedFunction {
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
     #[inline]
-    pub fn call_async<'lua, A, R>(&'lua self, args: A) -> LocalBoxFuture<'lua, Result<R>>
+    pub async fn call_async<'lua, A, R>(&'lua self, args: A) -> Result<R>
     where
         A: IntoLuaMulti<'lua>,
         R: FromLuaMulti<'lua> + 'lua,
     {
-        self.to_ref().call_async(args)
+        self.to_ref().call_async(args).await
     }
 }
 
@@ -624,7 +605,8 @@ impl<'lua> Function<'lua> {
                 Ok(args) => args,
                 Err(e) => return Box::pin(future::err(e)),
             };
-            Box::pin(func(lua, args).and_then(move |ret| future::ready(ret.into_lua_multi(lua))))
+            let fut = func(lua, args);
+            Box::pin(async move { fut.await?.into_lua_multi(lua) })
         }))
     }
 }

src/lib.rs

@@ -82,6 +82,7 @@ mod macros;
 mod chunk;
 mod conversion;
 mod error;
+pub mod ffi;
 mod function;
 mod hook;
 mod lua;
@@ -103,7 +104,7 @@ mod value;
 
 pub mod prelude;
 
-pub use ffi::{lua_CFunction, lua_State};
+pub use self::ffi::{lua_CFunction, lua_State};
 
 pub use crate::chunk::{AsChunk, Chunk, ChunkMode};
 pub use crate::error::{Error, ErrorContext, ExternalError, ExternalResult, Result};
@@ -130,7 +131,11 @@ pub use crate::hook::HookTriggers;
 
 #[cfg(any(feature = "luau", doc))]
 #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
-pub use crate::{chunk::Compiler, function::CoverageInfo, types::VmState};
+pub use crate::{
+    chunk::Compiler,
+    function::CoverageInfo,
+    types::{Vector, VmState},
+};
 
 #[cfg(feature = "async")]
 pub use crate::thread::AsyncThread;

src/lua.rs

@@ -50,12 +50,15 @@ use crate::{hook::HookTriggers, types::HookCallback};
 #[cfg(feature = "luau")]
 use crate::types::InterruptCallback;
 #[cfg(any(feature = "luau", doc))]
-use crate::{chunk::Compiler, types::VmState};
+use crate::{
+    chunk::Compiler,
+    types::{Vector, VmState},
+};
 
 #[cfg(feature = "async")]
 use {
     crate::types::{AsyncCallback, AsyncCallbackUpvalue, AsyncPollUpvalue},
-    futures_util::future::{self, Future, TryFutureExt},
+    futures_util::future::{self, Future},
     futures_util::task::{noop_waker_ref, Context, Poll, Waker},
 };
 
@@ -1555,6 +1558,7 @@ impl Lua {
     ///
     /// # Safety
     /// This function is unsafe because provides a way to execute unsafe C function.
+    #[inline]
     pub unsafe fn create_c_function(&self, func: ffi::lua_CFunction) -> Result<Function> {
         let state = self.state();
         check_stack(state, 1)?;
@@ -1616,7 +1620,8 @@ impl Lua {
                 Ok(args) => args,
                 Err(e) => return Box::pin(future::err(e)),
             };
-            Box::pin(func(lua, args).and_then(move |ret| future::ready(ret.into_lua_multi(lua))))
+            let fut = func(lua, args);
+            Box::pin(async move { fut.await?.into_lua_multi(lua) })
         }))
     }
 
@@ -1624,6 +1629,13 @@ impl Lua {
     ///
     /// Equivalent to `coroutine.create`.
     pub fn create_thread<'lua>(&'lua self, func: Function) -> Result<Thread<'lua>> {
+        self.create_thread_inner(&func)
+    }
+
+    /// Wraps a Lua function into a new thread (or coroutine).
+    ///
+    /// Takes function by reference.
+    fn create_thread_inner<'lua>(&'lua self, func: &Function) -> Result<Thread<'lua>> {
         let state = self.state();
         unsafe {
             let _sg = StackGuard::new(state);
@@ -1672,7 +1684,7 @@ impl Lua {
                 return Ok(Thread(LuaRef::new(self, index)));
             }
         };
-        self.create_thread(func.clone())
+        self.create_thread_inner(func)
     }
 
     /// Resets thread (coroutine) and returns to the pool for later use.
@@ -2270,7 +2282,7 @@ impl Lua {
         extra.app_data.remove()
     }
 
-    // Uses 2 stack spaces, does not call checkstack
+    /// Uses 2 stack spaces, does not call checkstack
     pub(crate) unsafe fn push_value(&self, value: Value) -> Result<()> {
         let state = self.state();
         match value {
@@ -2295,8 +2307,11 @@ impl Lua {
             }
 
             #[cfg(feature = "luau")]
-            Value::Vector(x, y, z) => {
-                ffi::lua_pushvector(state, x, y, z);
+            Value::Vector(v) => {
+                #[cfg(not(feature = "luau-vector4"))]
+                ffi::lua_pushvector(state, v.x(), v.y(), v.z());
+                #[cfg(feature = "luau-vector4")]
+                ffi::lua_pushvector(state, v.x(), v.y(), v.z(), v.w());
             }
 
             Value::String(s) => {
@@ -2328,7 +2343,7 @@ impl Lua {
         Ok(())
     }
 
-    // Uses 2 stack spaces, does not call checkstack
+    /// Uses 2 stack spaces, does not call checkstack
     pub(crate) unsafe fn pop_value(&self) -> Value {
         let state = self.state();
         match ffi::lua_type(state, -1) {
@@ -2379,7 +2394,10 @@ impl Lua {
             ffi::LUA_TVECTOR => {
                 let v = ffi::lua_tovector(state, -1);
                 mlua_debug_assert!(!v.is_null(), "vector is null");
-                let vec = Value::Vector(*v, *v.add(1), *v.add(2));
+                #[cfg(not(feature = "luau-vector4"))]
+                let vec = Value::Vector(Vector([*v, *v.add(1), *v.add(2)]));
+                #[cfg(feature = "luau-vector4")]
+                let vec = Value::Vector(Vector([*v, *v.add(1), *v.add(2), *v.add(3)]));
                 ffi::lua_pop(state, 1);
                 vec
             }
@@ -2658,18 +2676,17 @@ impl Lua {
         }
     }
 
-    // Pushes a LuaRef value onto the stack, checking that it's a registered
+    // Returns `TypeId` for the LuaRef, checking that it's a registered
     // and not destructed UserData.
-    // Uses 2 stack spaces, does not call checkstack.
-    pub(crate) unsafe fn push_userdata_ref(&self, lref: &LuaRef) -> Result<Option<TypeId>> {
-        let state = self.state();
-        self.push_ref(lref);
-        if ffi::lua_getmetatable(state, -1) == 0 {
-            ffi::lua_pop(state, 1);
+    //
+    // Returns `None` if the userdata is registered but non-static.
+    pub(crate) unsafe fn get_userdata_type_id(&self, lref: &LuaRef) -> Result<Option<TypeId>> {
+        let ref_thread = self.ref_thread();
+        if ffi::lua_getmetatable(ref_thread, lref.index) == 0 {
             return Err(Error::UserDataTypeMismatch);
         }
-        let mt_ptr = ffi::lua_topointer(state, -1);
-        ffi::lua_pop(state, 1);
+        let mt_ptr = ffi::lua_topointer(ref_thread, -1);
+        ffi::lua_pop(ref_thread, 1);
 
         // Fast path to skip looking up the metatable in the map
         let (last_mt, last_type_id) = (*self.extra.get()).last_checked_userdata_mt;
@@ -2689,6 +2706,14 @@ impl Lua {
         }
     }
 
+    // Pushes a LuaRef (userdata) value onto the stack, returning their `TypeId`.
+    // Uses 1 stack space, does not call checkstack.
+    pub(crate) unsafe fn push_userdata_ref(&self, lref: &LuaRef) -> Result<Option<TypeId>> {
+        let type_id = self.get_userdata_type_id(lref)?;
+        self.push_ref(lref);
+        Ok(type_id)
+    }
+
     // Creates a Function out of a Callback containing a 'static Fn. This is safe ONLY because the
     // Fn is 'static, otherwise it could capture 'lua arguments improperly. Without ATCs, we
     // cannot easily deal with the "correct" callback type of:
@@ -2774,8 +2799,7 @@ impl Lua {
         ))]
         unsafe {
             if !(*self.extra.get()).libs.contains(StdLib::COROUTINE) {
-                load_from_std_lib(self.main_state, StdLib::COROUTINE)?;
-                (*self.extra.get()).libs |= StdLib::COROUTINE;
+                return Err(Error::RuntimeError("StdLib::COROUTINE is not loaded".to_owned()));
             }
         }
 

src/luau.rs

@@ -126,6 +126,12 @@ unsafe extern "C" fn lua_vector(state: *mut ffi::lua_State) -> c_int {
     let x = ffi::luaL_checknumber(state, 1) as c_float;
     let y = ffi::luaL_checknumber(state, 2) as c_float;
     let z = ffi::luaL_checknumber(state, 3) as c_float;
+    #[cfg(feature = "luau-vector4")]
+    let w = ffi::luaL_checknumber(state, 4) as c_float;
+
+    #[cfg(not(feature = "luau-vector4"))]
     ffi::lua_pushvector(state, x, y, z);
+    #[cfg(feature = "luau-vector4")]
+    ffi::lua_pushvector(state, x, y, z, w);
     1
 }

src/macros.rs

@@ -69,14 +69,23 @@ macro_rules! mlua_debug_assert {
     };
 }
 
+#[cfg(debug_assertions)]
 macro_rules! mlua_expect {
-    ($res:expr, $msg:expr) => {
+    ($res:expr, $msg:expr $(,)?) => {
         $res.expect(bug_msg!($msg))
     };
+}
 
-    ($res:expr, $msg:expr,) => {
-        mlua_expect!($res, $msg)
-    };
+#[cfg(not(debug_assertions))]
+macro_rules! mlua_expect {
+    ($res:expr, $msg:expr $(,)?) => {{
+        let x;
+        #[allow(unused_unsafe)]
+        {
+            x = unsafe { $res.into_iter().next().unwrap_unchecked() };
+        }
+        x
+    }};
 }
 
 #[cfg(feature = "module")]

src/prelude.rs

@@ -23,7 +23,7 @@ pub use crate::HookTriggers as LuaHookTriggers;
 
 #[cfg(feature = "luau")]
 #[doc(no_inline)]
-pub use crate::{CoverageInfo as LuaCoverageInfo, VmState as LuaVmState};
+pub use crate::{CoverageInfo as LuaCoverageInfo, Vector as LuaVector, VmState as LuaVmState};
 
 #[cfg(feature = "async")]
 #[doc(no_inline)]

src/scope.rs

@@ -611,12 +611,28 @@ impl<'lua, T: UserData> UserDataMethods<'lua, T> for NonStaticUserDataMethods<'l
     }
 
     #[cfg(feature = "async")]
-    fn add_async_method<M, A, MR, R>(&mut self, _name: impl AsRef<str>, _method: M)
+    fn add_async_method<'s, M, A, MR, R>(&mut self, _name: impl AsRef<str>, _method: M)
     where
-        T: Clone,
-        M: Fn(&'lua Lua, T, A) -> MR + MaybeSend + 'static,
+        'lua: 's,
+        T: 'static,
+        M: Fn(&'lua Lua, &'s T, A) -> MR + MaybeSend + 'static,
         A: FromLuaMulti<'lua>,
-        MR: Future<Output = Result<R>> + 'lua,
+        MR: Future<Output = Result<R>> + 's,
+        R: IntoLuaMulti<'lua>,
+    {
+        // The panic should never happen as async non-static code wouldn't compile
+        // Non-static lifetime must be bounded to 'lua lifetime
+        panic!("asynchronous methods are not supported for non-static userdata")
+    }
+
+    #[cfg(feature = "async")]
+    fn add_async_method_mut<'s, M, A, MR, R>(&mut self, _name: impl AsRef<str>, _method: M)
+    where
+        'lua: 's,
+        T: 'static,
+        M: Fn(&'lua Lua, &'s mut T, A) -> MR + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        MR: Future<Output = Result<R>> + 's,
         R: IntoLuaMulti<'lua>,
     {
         // The panic should never happen as async non-static code wouldn't compile
@@ -686,12 +702,28 @@ impl<'lua, T: UserData> UserDataMethods<'lua, T> for NonStaticUserDataMethods<'l
     }
 
     #[cfg(all(feature = "async", not(any(feature = "lua51", feature = "luau"))))]
-    fn add_async_meta_method<M, A, MR, R>(&mut self, _name: impl AsRef<str>, _method: M)
+    fn add_async_meta_method<'s, M, A, MR, R>(&mut self, _name: impl AsRef<str>, _method: M)
     where
-        T: Clone,
-        M: Fn(&'lua Lua, T, A) -> MR + MaybeSend + 'static,
+        'lua: 's,
+        T: 'static,
+        M: Fn(&'lua Lua, &'s T, A) -> MR + MaybeSend + 'static,
         A: FromLuaMulti<'lua>,
-        MR: Future<Output = Result<R>> + 'lua,
+        MR: Future<Output = Result<R>> + 's,
+        R: IntoLuaMulti<'lua>,
+    {
+        // The panic should never happen as async non-static code wouldn't compile
+        // Non-static lifetime must be bounded to 'lua lifetime
+        panic!("asynchronous meta methods are not supported for non-static userdata")
+    }
+
+    #[cfg(all(feature = "async", not(any(feature = "lua51", feature = "luau"))))]
+    fn add_async_meta_method_mut<'s, M, A, MR, R>(&mut self, _name: impl AsRef<str>, _method: M)
+    where
+        'lua: 's,
+        T: 'static,
+        M: Fn(&'lua Lua, &'s mut T, A) -> MR + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        MR: Future<Output = Result<R>> + 's,
         R: IntoLuaMulti<'lua>,
     {
         // The panic should never happen as async non-static code wouldn't compile

src/serde/de.rs

@@ -124,7 +124,7 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
             #[allow(clippy::useless_conversion)]
             Value::Number(n) => visitor.visit_f64(n.into()),
             #[cfg(feature = "luau")]
-            Value::Vector(_, _, _) => self.deserialize_seq(visitor),
+            Value::Vector(_) => self.deserialize_seq(visitor),
             Value::String(s) => match s.to_str() {
                 Ok(s) => visitor.visit_str(s),
                 Err(_) => visitor.visit_bytes(s.as_bytes()),
@@ -223,9 +223,9 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
     {
         match self.value {
             #[cfg(feature = "luau")]
-            Value::Vector(x, y, z) => {
+            Value::Vector(vec) => {
                 let mut deserializer = VecDeserializer {
-                    vec: [x, y, z],
+                    vec,
                     next: 0,
                     options: self.options,
                     visited: self.visited,
@@ -412,7 +412,7 @@ impl<'lua, 'de> de::SeqAccess<'de> for SeqDeserializer<'lua> {
 
 #[cfg(feature = "luau")]
 struct VecDeserializer {
-    vec: [f32; 3],
+    vec: crate::types::Vector,
     next: usize,
     options: Options,
     visited: Rc<RefCell<FxHashSet<*const c_void>>>,
@@ -426,7 +426,7 @@ impl<'de> de::SeqAccess<'de> for VecDeserializer {
     where
         T: de::DeserializeSeed<'de>,
     {
-        match self.vec.get(self.next) {
+        match self.vec.0.get(self.next) {
             Some(&n) => {
                 self.next += 1;
                 let visited = Rc::clone(&self.visited);
@@ -439,7 +439,7 @@ impl<'de> de::SeqAccess<'de> for VecDeserializer {
     }
 
     fn size_hint(&self) -> Option<usize> {
-        Some(3)
+        Some(crate::types::Vector::SIZE)
     }
 }
 

src/serde/ser.rs

@@ -7,8 +7,6 @@ use crate::error::{Error, Result};
 use crate::lua::Lua;
 use crate::string::String;
 use crate::table::Table;
-use crate::types::Integer;
-use crate::util::{check_stack, StackGuard};
 use crate::value::{IntoLua, Value};
 
 /// A struct for serializing Rust values into Lua values.
@@ -120,9 +118,9 @@ impl<'lua> ser::Serializer for Serializer<'lua> {
 
     // Associated types for keeping track of additional state while serializing
     // compound data structures like sequences and maps.
-    type SerializeSeq = SerializeVec<'lua>;
-    type SerializeTuple = SerializeVec<'lua>;
-    type SerializeTupleStruct = SerializeVec<'lua>;
+    type SerializeSeq = SerializeSeq<'lua>;
+    type SerializeTuple = SerializeSeq<'lua>;
+    type SerializeTupleStruct = SerializeSeq<'lua>;
     type SerializeTupleVariant = SerializeTupleVariant<'lua>;
     type SerializeMap = SerializeMap<'lua>;
     type SerializeStruct = SerializeMap<'lua>;
@@ -240,8 +238,7 @@ impl<'lua> ser::Serializer for Serializer<'lua> {
         if self.options.set_array_metatable {
             table.set_metatable(Some(self.lua.array_metatable()));
         }
-        let options = self.options;
-        Ok(SerializeVec { table, options })
+        Ok(SerializeSeq::new(table, self.options))
     }
 
     #[inline]
@@ -252,9 +249,14 @@ impl<'lua> ser::Serializer for Serializer<'lua> {
     #[inline]
     fn serialize_tuple_struct(
         self,
-        _name: &'static str,
+        name: &'static str,
         len: usize,
     ) -> Result<Self::SerializeTupleStruct> {
+        #[cfg(feature = "luau")]
+        if name == "Vector" && len == crate::types::Vector::SIZE {
+            return Ok(SerializeSeq::new_vector(self.lua, self.options));
+        }
+        _ = name;
         self.serialize_seq(Some(len))
     }
 
@@ -305,12 +307,40 @@ impl<'lua> ser::Serializer for Serializer<'lua> {
 }
 
 #[doc(hidden)]
-pub struct SerializeVec<'lua> {
-    table: Table<'lua>,
+pub struct SerializeSeq<'lua> {
+    lua: &'lua Lua,
+    #[cfg(feature = "luau")]
+    vector: Option<crate::types::Vector>,
+    table: Option<Table<'lua>>,
+    next: usize,
     options: Options,
 }
 
-impl<'lua> ser::SerializeSeq for SerializeVec<'lua> {
+impl<'lua> SerializeSeq<'lua> {
+    const fn new(table: Table<'lua>, options: Options) -> Self {
+        Self {
+            lua: table.0.lua,
+            #[cfg(feature = "luau")]
+            vector: None,
+            table: Some(table),
+            next: 0,
+            options,
+        }
+    }
+
+    #[cfg(feature = "luau")]
+    const fn new_vector(lua: &'lua Lua, options: Options) -> Self {
+        Self {
+            lua,
+            vector: Some(crate::types::Vector::zero()),
+            table: None,
+            next: 0,
+            options,
+        }
+    }
+}
+
+impl<'lua> ser::SerializeSeq for SerializeSeq<'lua> {
     type Ok = Value<'lua>;
     type Error = Error;
 
@@ -318,35 +348,19 @@ impl<'lua> ser::SerializeSeq for SerializeVec<'lua> {
     where
         T: Serialize + ?Sized,
     {
-        let lua = self.table.0.lua;
-        let state = lua.state();
-        let value = lua.to_value_with(value, self.options)?;
-        unsafe {
-            let _sg = StackGuard::new(state);
-            check_stack(state, 4)?;
-
-            lua.push_ref(&self.table.0);
-            lua.push_value(value)?;
-            if lua.unlikely_memory_error() {
-                let len = ffi::lua_rawlen(state, -2) as Integer;
-                ffi::lua_rawseti(state, -2, len + 1);
-                ffi::lua_pop(state, 1);
-                Ok(())
-            } else {
-                protect_lua!(state, 2, 0, fn(state) {
-                    let len = ffi::lua_rawlen(state, -2) as Integer;
-                    ffi::lua_rawseti(state, -2, len + 1);
-                })
-            }
-        }
+        let value = self.lua.to_value_with(value, self.options)?;
+        let table = self.table.as_ref().unwrap();
+        table.raw_seti(self.next + 1, value)?;
+        self.next += 1;
+        Ok(())
     }
 
     fn end(self) -> Result<Value<'lua>> {
-        Ok(Value::Table(self.table))
+        Ok(Value::Table(self.table.unwrap()))
     }
 }
 
-impl<'lua> ser::SerializeTuple for SerializeVec<'lua> {
+impl<'lua> ser::SerializeTuple for SerializeSeq<'lua> {
     type Ok = Value<'lua>;
     type Error = Error;
 
@@ -362,7 +376,7 @@ impl<'lua> ser::SerializeTuple for SerializeVec<'lua> {
     }
 }
 
-impl<'lua> ser::SerializeTupleStruct for SerializeVec<'lua> {
+impl<'lua> ser::SerializeTupleStruct for SerializeSeq<'lua> {
     type Ok = Value<'lua>;
     type Error = Error;
 
@@ -370,10 +384,22 @@ impl<'lua> ser::SerializeTupleStruct for SerializeVec<'lua> {
     where
         T: Serialize + ?Sized,
     {
+        #[cfg(feature = "luau")]
+        if let Some(vector) = self.vector.as_mut() {
+            let value = self.lua.to_value_with(value, self.options)?;
+            let value = self.lua.unpack(value)?;
+            vector.0[self.next] = value;
+            self.next += 1;
+            return Ok(());
+        }
         ser::SerializeSeq::serialize_element(self, value)
     }
 
     fn end(self) -> Result<Value<'lua>> {
+        #[cfg(feature = "luau")]
+        if let Some(vector) = self.vector {
+            return Ok(Value::Vector(vector));
+        }
         ser::SerializeSeq::end(self)
     }
 }
@@ -394,9 +420,7 @@ impl<'lua> ser::SerializeTupleVariant for SerializeTupleVariant<'lua> {
         T: Serialize + ?Sized,
     {
         let lua = self.table.0.lua;
-        let idx = self.table.raw_len() + 1;
-        self.table
-            .raw_insert(idx, lua.to_value_with(value, self.options)?)
+        self.table.raw_push(lua.to_value_with(value, self.options)?)
     }
 
     fn end(self) -> Result<Value<'lua>> {

src/string.rs

@@ -41,6 +41,10 @@ impl OwnedString {
 }
 
 impl<'lua> String<'lua> {
+    pub fn as_raw_ref(&self) -> &LuaRef<'lua> {
+        &self.0
+    }
+
     /// Get a `&str` slice if the Lua string is valid UTF-8.
     ///
     /// # Examples
@@ -139,8 +143,7 @@ impl<'lua> String<'lua> {
     /// Typically this function is used only for hashing and debug information.
     #[inline]
     pub fn to_pointer(&self) -> *const c_void {
-        let ref_thread = self.0.lua.ref_thread();
-        unsafe { ffi::lua_topointer(ref_thread, self.0.index) }
+        self.0.to_pointer()
     }
 
     /// Convert this handle to owned version.

src/table.rs

@@ -47,6 +47,10 @@ impl OwnedTable {
 
 #[allow(clippy::len_without_is_empty)]
 impl<'lua> Table<'lua> {
+    pub fn as_raw_ref(&self) -> &LuaRef<'lua> {
+        &self.0
+    }
+
     /// Sets a key-value pair in the table.
     ///
     /// If the value is `nil`, this will effectively remove the pair.
@@ -557,6 +561,7 @@ impl<'lua> Table<'lua> {
     /// Requires `feature = "luau"`
     #[cfg(any(feature = "luau", doc))]
     #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+    #[inline]
     pub fn set_readonly(&self, enabled: bool) {
         let ref_thread = self.0.lua.ref_thread();
         unsafe {
@@ -568,11 +573,22 @@ impl<'lua> Table<'lua> {
         }
     }
 
+    #[inline]
+    pub fn set_safe(&self, enabled: bool) {
+        let ref_thread = self.0.lua.ref_thread();
+        let enabled = enabled as _;
+        unsafe {
+            ffi::lua_setreadonly(ref_thread, self.0.index, enabled);
+            ffi::lua_setsafeenv(ref_thread, self.0.index, enabled);
+        }
+    }
+
     /// Returns `readonly` attribute of the table.
     ///
     /// Requires `feature = "luau"`
     #[cfg(any(feature = "luau", doc))]
     #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+    #[inline]
     pub fn is_readonly(&self) -> bool {
         let ref_thread = self.0.lua.ref_thread();
         unsafe { ffi::lua_getreadonly(ref_thread, self.0.index) != 0 }
@@ -586,8 +602,7 @@ impl<'lua> Table<'lua> {
     /// Typically this function is used only for hashing and debug information.
     #[inline]
     pub fn to_pointer(&self) -> *const c_void {
-        let ref_thread = self.0.lua.ref_thread();
-        unsafe { ffi::lua_topointer(ref_thread, self.0.index) }
+        self.0.to_pointer()
     }
 
     /// Convert this handle to owned version.
@@ -720,6 +735,32 @@ impl<'lua> Table<'lua> {
         }
     }
 
+    /// Sets element value at position `idx` without invoking metamethods.
+    #[allow(dead_code)]
+    pub(crate) fn raw_seti<V: IntoLua<'lua>>(&self, idx: usize, value: V) -> Result<()> {
+        #[cfg(feature = "luau")]
+        self.check_readonly_write()?;
+
+        let lua = self.0.lua;
+        let state = lua.state();
+        let value = value.into_lua(lua)?;
+
+        unsafe {
+            let _sg = StackGuard::new(state);
+            check_stack(state, 5)?;
+
+            lua.push_ref(&self.0);
+            lua.push_value(value)?;
+
+            if lua.unlikely_memory_error() {
+                ffi::lua_rawseti(state, -2, idx as _);
+            } else {
+                protect_lua!(state, 2, 0, |state| ffi::lua_rawseti(state, -2, idx as _))?;
+            }
+            Ok(())
+        }
+    }
+
     #[cfg(feature = "serialize")]
     pub(crate) fn is_array(&self) -> bool {
         let lua = self.0.lua;
@@ -797,6 +838,56 @@ impl<'lua> AsRef<Table<'lua>> for Table<'lua> {
     }
 }
 
+impl<'lua, T> PartialEq<[T]> for Table<'lua>
+where
+    T: IntoLua<'lua> + Clone,
+{
+    fn eq(&self, other: &[T]) -> bool {
+        let lua = self.0.lua;
+        let state = lua.state();
+        unsafe {
+            let _sg = StackGuard::new(state);
+            assert_stack(state, 4);
+
+            lua.push_ref(&self.0);
+
+            let len = ffi::lua_rawlen(state, -1);
+            for i in 0..len {
+                ffi::lua_rawgeti(state, -1, (i + 1) as _);
+                let val = lua.pop_value();
+                if val == Nil {
+                    return i == other.len();
+                }
+                match other.get(i).map(|v| v.clone().into_lua(lua)) {
+                    Some(Ok(other_val)) if val == other_val => continue,
+                    _ => return false,
+                }
+            }
+        }
+        true
+    }
+}
+
+impl<'lua, T> PartialEq<&[T]> for Table<'lua>
+where
+    T: IntoLua<'lua> + Clone,
+{
+    #[inline]
+    fn eq(&self, other: &&[T]) -> bool {
+        self == *other
+    }
+}
+
+impl<'lua, T, const N: usize> PartialEq<[T; N]> for Table<'lua>
+where
+    T: IntoLua<'lua> + Clone,
+{
+    #[inline]
+    fn eq(&self, other: &[T; N]) -> bool {
+        self == &other[..]
+    }
+}
+
 /// An extension trait for `Table`s that provides a variety of convenient functionality.
 pub trait TableExt<'lua>: Sealed {
     /// Calls the table as function assuming it has `__call` metamethod.
@@ -812,11 +903,10 @@ pub trait TableExt<'lua>: Sealed {
     /// The metamethod is called with the table as its first argument, followed by the passed arguments.
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn call_async<'fut, A, R>(&self, args: A) -> LocalBoxFuture<'fut, Result<R>>
+    fn call_async<A, R>(&self, args: A) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut;
+        R: FromLuaMulti<'lua> + 'lua;
 
     /// Gets the function associated to `key` from the table and executes it,
     /// passing the table itself along with `args` as function arguments.
@@ -852,12 +942,11 @@ pub trait TableExt<'lua>: Sealed {
     /// This might invoke the `__index` metamethod.
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn call_async_method<'fut, K, A, R>(&self, key: K, args: A) -> LocalBoxFuture<'fut, Result<R>>
+    fn call_async_method<K, A, R>(&self, key: K, args: A) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         K: IntoLua<'lua>,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut;
+        R: FromLuaMulti<'lua> + 'lua;
 
     /// Gets the function associated to `key` from the table and asynchronously executes it,
     /// passing `args` as function arguments and returning Future.
@@ -867,16 +956,11 @@ pub trait TableExt<'lua>: Sealed {
     /// This might invoke the `__index` metamethod.
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn call_async_function<'fut, K, A, R>(
-        &self,
-        key: K,
-        args: A,
-    ) -> LocalBoxFuture<'fut, Result<R>>
+    fn call_async_function<K, A, R>(&self, key: K, args: A) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         K: IntoLua<'lua>,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut;
+        R: FromLuaMulti<'lua> + 'lua;
 }
 
 impl<'lua> TableExt<'lua> for Table<'lua> {
@@ -890,13 +974,17 @@ impl<'lua> TableExt<'lua> for Table<'lua> {
     }
 
     #[cfg(feature = "async")]
-    fn call_async<'fut, A, R>(&self, args: A) -> LocalBoxFuture<'fut, Result<R>>
+    fn call_async<A, R>(&self, args: A) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut,
+        R: FromLuaMulti<'lua> + 'lua,
     {
-        Function(self.0.clone()).call_async(args)
+        let args = match args.into_lua_multi(self.0.lua) {
+            Ok(args) => args,
+            Err(e) => return Box::pin(future::err(e)),
+        };
+        let func = Function(self.0.clone());
+        Box::pin(async move { func.call_async(args).await })
     }
 
     fn call_method<K, A, R>(&self, key: K, args: A) -> Result<R>
@@ -921,12 +1009,11 @@ impl<'lua> TableExt<'lua> for Table<'lua> {
     }
 
     #[cfg(feature = "async")]
-    fn call_async_method<'fut, K, A, R>(&self, key: K, args: A) -> LocalBoxFuture<'fut, Result<R>>
+    fn call_async_method<K, A, R>(&self, key: K, args: A) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         K: IntoLua<'lua>,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut,
+        R: FromLuaMulti<'lua> + 'lua,
     {
         let lua = self.0.lua;
         let mut args = match args.into_lua_multi(lua) {
@@ -938,15 +1025,19 @@ impl<'lua> TableExt<'lua> for Table<'lua> {
     }
 
     #[cfg(feature = "async")]
-    fn call_async_function<'fut, K, A, R>(&self, key: K, args: A) -> LocalBoxFuture<'fut, Result<R>>
+    fn call_async_function<K, A, R>(&self, key: K, args: A) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         K: IntoLua<'lua>,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut,
+        R: FromLuaMulti<'lua> + 'lua,
     {
+        let lua = self.0.lua;
+        let args = match args.into_lua_multi(lua) {
+            Ok(args) => args,
+            Err(e) => return Box::pin(future::err(e)),
+        };
         match self.get::<_, Function>(key) {
-            Ok(func) => func.call_async(args),
+            Ok(func) => Box::pin(async move { func.call_async(args).await }),
             Err(e) => Box::pin(future::err(e)),
         }
     }

src/thread.rs

@@ -73,6 +73,10 @@ pub struct AsyncThread<'lua, R> {
 }
 
 impl<'lua> Thread<'lua> {
+    pub fn as_raw_ref(&self) -> &LuaRef<'lua> {
+        &self.0
+    }
+
     /// Resumes execution of this thread.
     ///
     /// Equivalent to `coroutine.resume`.
@@ -88,6 +92,8 @@ impl<'lua> Thread<'lua> {
     /// If the thread calls `coroutine.yield`, returns the values passed to `yield`. If the thread
     /// `return`s values from its main function, returns those.
     ///
+    /// Also returns `true` if the coroutine is yielded.
+    ///
     /// # Examples
     ///
     /// ```
@@ -114,7 +120,7 @@ impl<'lua> Thread<'lua> {
     /// # Ok(())
     /// # }
     /// ```
-    pub fn resume<A, R>(&self, args: A) -> Result<R>
+    pub fn resume<A, R>(&self, args: A) -> Result<(bool, R)>
     where
         A: IntoLuaMulti<'lua>,
         R: FromLuaMulti<'lua>,
@@ -124,7 +130,7 @@ impl<'lua> Thread<'lua> {
 
         let mut args = args.into_lua_multi(lua)?;
         let nargs = args.len() as c_int;
-        let results = unsafe {
+        let (yielded, results) = unsafe {
             let _sg = StackGuard::new(state);
             check_stack(state, cmp::max(nargs + 1, 3))?;
 
@@ -164,9 +170,9 @@ impl<'lua> Thread<'lua> {
             for _ in 0..nresults {
                 results.push_front(lua.pop_value());
             }
-            results
+            (ret == ffi::LUA_YIELD, results)
         };
-        R::from_lua_multi(results, lua)
+        R::from_lua_multi(results, lua).map(|result| (yielded, result))
     }
 
     /// Gets the status of the thread.
@@ -428,9 +434,9 @@ where
         // This is safe as we are not moving the whole struct
         let this = unsafe { self.get_unchecked_mut() };
         let ret: MultiValue = if let Some(args) = this.args0.take() {
-            this.thread.resume(args?)?
+            this.thread.resume(args?)?.1
         } else {
-            this.thread.resume(())?
+            this.thread.resume(())?.1
         };
 
         if is_poll_pending(&ret) {
@@ -462,9 +468,9 @@ where
         // This is safe as we are not moving the whole struct
         let this = unsafe { self.get_unchecked_mut() };
         let ret: MultiValue = if let Some(args) = this.args0.take() {
-            this.thread.resume(args?)?
+            this.thread.resume(args?)?.1
         } else {
-            this.thread.resume(())?
+            this.thread.resume(())?.1
         };
 
         if is_poll_pending(&ret) {

src/types.rs

@@ -26,6 +26,9 @@ use crate::value::MultiValue;
 #[cfg(feature = "unstable")]
 use {crate::lua::LuaInner, std::marker::PhantomData};
 
+#[cfg(all(feature = "luau", feature = "serialize"))]
+use serde::ser::{Serialize, SerializeTupleStruct, Serializer};
+
 /// Type of Lua integer numbers.
 pub type Integer = ffi::lua_Integer;
 /// Type of Lua floating point numbers.
@@ -91,6 +94,92 @@ pub trait MaybeSend {}
 #[cfg(not(feature = "send"))]
 impl<T> MaybeSend for T {}
 
+/// A Luau vector type.
+///
+/// By default vectors are 3-dimensional, but can be 4-dimensional
+/// if the `luau-vector4` feature is enabled.
+#[cfg(any(feature = "luau", doc))]
+#[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+#[derive(Debug, Default, Clone, Copy, PartialEq)]
+pub struct Vector(pub(crate) [f32; Self::SIZE]);
+
+#[cfg(feature = "luau")]
+impl fmt::Display for Vector {
+    #[rustfmt::skip]
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        #[cfg(not(feature = "luau-vector4"))]
+        return write!(f, "vector({}, {}, {})", self.x(), self.y(), self.z());
+        #[cfg(feature = "luau-vector4")]
+        return write!(f, "vector({}, {}, {}, {})", self.x(), self.y(), self.z(), self.w());
+    }
+}
+
+#[cfg(feature = "luau")]
+impl Vector {
+    pub(crate) const SIZE: usize = if cfg!(feature = "luau-vector4") { 4 } else { 3 };
+
+    /// Creates a new vector.
+    #[cfg(not(feature = "luau-vector4"))]
+    pub const fn new(x: f32, y: f32, z: f32) -> Self {
+        Self([x, y, z])
+    }
+
+    /// Creates a new vector.
+    #[cfg(feature = "luau-vector4")]
+    pub const fn new(x: f32, y: f32, z: f32, w: f32) -> Self {
+        Self([x, y, z, w])
+    }
+
+    /// Creates a new vector with all components set to `0.0`.
+    #[doc(hidden)]
+    pub const fn zero() -> Self {
+        Self([0.0; Self::SIZE])
+    }
+
+    /// Returns 1st component of the vector.
+    pub const fn x(&self) -> f32 {
+        self.0[0]
+    }
+
+    /// Returns 2nd component of the vector.
+    pub const fn y(&self) -> f32 {
+        self.0[1]
+    }
+
+    /// Returns 3rd component of the vector.
+    pub const fn z(&self) -> f32 {
+        self.0[2]
+    }
+
+    /// Returns 4th component of the vector.
+    #[cfg(any(feature = "luau-vector4", doc))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "luau-vector4")))]
+    pub const fn w(&self) -> f32 {
+        self.0[3]
+    }
+}
+
+#[cfg(all(feature = "luau", feature = "serialize"))]
+impl Serialize for Vector {
+    fn serialize<S: Serializer>(&self, serializer: S) -> StdResult<S::Ok, S::Error> {
+        let mut ts = serializer.serialize_tuple_struct("Vector", Self::SIZE)?;
+        ts.serialize_field(&self.x())?;
+        ts.serialize_field(&self.y())?;
+        ts.serialize_field(&self.z())?;
+        #[cfg(feature = "luau-vector4")]
+        ts.serialize_field(&self.w())?;
+        ts.end()
+    }
+}
+
+#[cfg(feature = "luau")]
+impl PartialEq<[f32; Self::SIZE]> for Vector {
+    #[inline]
+    fn eq(&self, other: &[f32; Self::SIZE]) -> bool {
+        self.0 == *other
+    }
+}
+
 pub(crate) struct DestructedUserdata;
 
 /// An auto generated key into the Lua registry.
@@ -184,7 +273,7 @@ impl RegistryKey {
     }
 }
 
-pub(crate) struct LuaRef<'lua> {
+pub struct LuaRef<'lua> {
     pub(crate) lua: &'lua Lua,
     pub(crate) index: c_int,
     pub(crate) drop: bool,
@@ -207,6 +296,12 @@ impl<'lua> LuaRef<'lua> {
         mem::forget(self);
         owned_ref
     }
+
+    #[inline]
+    pub fn to_pointer(&self) -> *const std::os::raw::c_void {
+        let ref_thread = self.lua.ref_thread();
+        unsafe { ffi::lua_topointer(ref_thread, self.index) }
+    }
 }
 
 impl<'lua> fmt::Debug for LuaRef<'lua> {

src/userdata.rs

@@ -259,8 +259,7 @@ pub trait UserDataMethods<'lua, T> {
         A: FromLuaMulti<'lua>,
         R: IntoLuaMulti<'lua>;
 
-    /// Add an async method which accepts a `T` as the first parameter and returns Future.
-    /// The passed `T` is cloned from the original value.
+    /// Add an async method which accepts a `&T` as the first parameter and returns Future.
     ///
     /// Refer to [`add_method`] for more information about the implementation.
     ///
@@ -269,12 +268,31 @@ pub trait UserDataMethods<'lua, T> {
     /// [`add_method`]: #method.add_method
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn add_async_method<M, A, MR, R>(&mut self, name: impl AsRef<str>, method: M)
+    fn add_async_method<'s, M, A, MR, R>(&mut self, name: impl AsRef<str>, method: M)
     where
-        T: Clone,
-        M: Fn(&'lua Lua, T, A) -> MR + MaybeSend + 'static,
+        'lua: 's,
+        T: 'static,
+        M: Fn(&'lua Lua, &'s T, A) -> MR + MaybeSend + 'static,
         A: FromLuaMulti<'lua>,
-        MR: Future<Output = Result<R>> + 'lua,
+        MR: Future<Output = Result<R>> + 's,
+        R: IntoLuaMulti<'lua>;
+
+    /// Add an async method which accepts a `&mut T` as the first parameter and returns Future.
+    ///
+    /// Refer to [`add_method`] for more information about the implementation.
+    ///
+    /// Requires `feature = "async"`
+    ///
+    /// [`add_method`]: #method.add_method
+    #[cfg(feature = "async")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
+    fn add_async_method_mut<'s, M, A, MR, R>(&mut self, name: impl AsRef<str>, method: M)
+    where
+        'lua: 's,
+        T: 'static,
+        M: Fn(&'lua Lua, &'s mut T, A) -> MR + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        MR: Future<Output = Result<R>> + 's,
         R: IntoLuaMulti<'lua>;
 
     /// Add a regular method as a function which accepts generic arguments, the first argument will
@@ -349,8 +367,7 @@ pub trait UserDataMethods<'lua, T> {
         A: FromLuaMulti<'lua>,
         R: IntoLuaMulti<'lua>;
 
-    /// Add an async metamethod which accepts a `T` as the first parameter and returns Future.
-    /// The passed `T` is cloned from the original value.
+    /// Add an async metamethod which accepts a `&T` as the first parameter and returns Future.
     ///
     /// This is an async version of [`add_meta_method`].
     ///
@@ -359,12 +376,31 @@ pub trait UserDataMethods<'lua, T> {
     /// [`add_meta_method`]: #method.add_meta_method
     #[cfg(all(feature = "async", not(any(feature = "lua51", feature = "luau"))))]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn add_async_meta_method<M, A, MR, R>(&mut self, name: impl AsRef<str>, method: M)
+    fn add_async_meta_method<'s, M, A, MR, R>(&mut self, name: impl AsRef<str>, method: M)
     where
-        T: Clone,
-        M: Fn(&'lua Lua, T, A) -> MR + MaybeSend + 'static,
+        'lua: 's,
+        T: 'static,
+        M: Fn(&'lua Lua, &'s T, A) -> MR + MaybeSend + 'static,
         A: FromLuaMulti<'lua>,
-        MR: Future<Output = Result<R>> + 'lua,
+        MR: Future<Output = Result<R>> + 's,
+        R: IntoLuaMulti<'lua>;
+
+    /// Add an async metamethod which accepts a `&mut T` as the first parameter and returns Future.
+    ///
+    /// This is an async version of [`add_meta_method_mut`].
+    ///
+    /// Requires `feature = "async"`
+    ///
+    /// [`add_meta_method_mut`]: #method.add_meta_method_mut
+    #[cfg(all(feature = "async", not(any(feature = "lua51", feature = "luau"))))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
+    fn add_async_meta_method_mut<'s, M, A, MR, R>(&mut self, name: impl AsRef<str>, method: M)
+    where
+        'lua: 's,
+        T: 'static,
+        M: Fn(&'lua Lua, &'s mut T, A) -> MR + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        MR: Future<Output = Result<R>> + 's,
         R: IntoLuaMulti<'lua>;
 
     /// Add a metamethod which accepts generic arguments.
@@ -770,6 +806,10 @@ impl OwnedAnyUserData {
 }
 
 impl<'lua> AnyUserData<'lua> {
+    pub fn as_raw_ref(&self) -> &LuaRef<'lua> {
+        &self.0
+    }
+
     /// Checks whether the type of this userdata is `T`.
     pub fn is<T: 'static>(&self) -> bool {
         match self.inspect(|_: &UserDataCell<T>| Ok(())) {
@@ -1055,6 +1095,11 @@ impl<'lua> AnyUserData<'lua> {
         OwnedAnyUserData(self.0.into_owned())
     }
 
+    #[inline(always)]
+    pub(crate) fn type_id(&self) -> Result<Option<TypeId>> {
+        unsafe { self.0.lua.get_userdata_type_id(&self.0) }
+    }
+
     /// Returns a type name of this `UserData` (from `__name` metatable field).
     pub(crate) fn type_name(&self) -> Result<Option<StdString>> {
         let lua = self.0.lua;

src/userdata_ext.rs

@@ -27,11 +27,10 @@ pub trait AnyUserDataExt<'lua>: Sealed {
     /// The metamethod is called with the userdata as its first argument, followed by the passed arguments.
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn call_async<'fut, A, R>(&self, args: A) -> LocalBoxFuture<'fut, Result<R>>
+    fn call_async<A, R>(&self, args: A) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut;
+        R: FromLuaMulti<'lua> + 'lua;
 
     /// Calls the userdata method, assuming it has `__index` metamethod
     /// and a function associated to `name`.
@@ -48,15 +47,14 @@ pub trait AnyUserDataExt<'lua>: Sealed {
     /// This might invoke the `__index` metamethod.
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn call_async_method<'fut, A, R>(
+    fn call_async_method<A, R>(
         &self,
         name: impl AsRef<str>,
         args: A,
-    ) -> LocalBoxFuture<'fut, Result<R>>
+    ) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut;
+        R: FromLuaMulti<'lua> + 'lua;
 
     /// Gets the function associated to `key` from the table and executes it,
     /// passing `args` as function arguments.
@@ -78,15 +76,14 @@ pub trait AnyUserDataExt<'lua>: Sealed {
     /// This might invoke the `__index` metamethod.
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn call_async_function<'fut, A, R>(
+    fn call_async_function<A, R>(
         &self,
         name: impl AsRef<str>,
         args: A,
-    ) -> LocalBoxFuture<'fut, Result<R>>
+    ) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut;
+        R: FromLuaMulti<'lua> + 'lua;
 }
 
 impl<'lua> AnyUserDataExt<'lua> for AnyUserData<'lua> {
@@ -127,18 +124,24 @@ impl<'lua> AnyUserDataExt<'lua> for AnyUserData<'lua> {
     }
 
     #[cfg(feature = "async")]
-    fn call_async<'fut, A, R>(&self, args: A) -> LocalBoxFuture<'fut, Result<R>>
+    fn call_async<A, R>(&self, args: A) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut,
+        R: FromLuaMulti<'lua> + 'lua,
     {
         let metatable = match self.get_metatable() {
             Ok(metatable) => metatable,
             Err(err) => return Box::pin(future::err(err)),
         };
         match metatable.get::<Value>(MetaMethod::Call) {
-            Ok(Value::Function(func)) => func.call_async((self.clone(), args)),
+            Ok(Value::Function(func)) => {
+                let mut args = match args.into_lua_multi(self.0.lua) {
+                    Ok(args) => args,
+                    Err(e) => return Box::pin(future::err(e)),
+                };
+                args.push_front(Value::UserData(self.clone()));
+                Box::pin(async move { func.call_async(args).await })
+            }
             Ok(_) => Box::pin(future::err(Error::RuntimeError(
                 "attempt to call a userdata value".to_string(),
             ))),
@@ -155,15 +158,14 @@ impl<'lua> AnyUserDataExt<'lua> for AnyUserData<'lua> {
     }
 
     #[cfg(feature = "async")]
-    fn call_async_method<'fut, A, R>(
+    fn call_async_method<A, R>(
         &self,
         name: impl AsRef<str>,
         args: A,
-    ) -> LocalBoxFuture<'fut, Result<R>>
+    ) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut,
+        R: FromLuaMulti<'lua> + 'lua,
     {
         self.call_async_function(name, (self.clone(), args))
     }
@@ -183,22 +185,28 @@ impl<'lua> AnyUserDataExt<'lua> for AnyUserData<'lua> {
     }
 
     #[cfg(feature = "async")]
-    fn call_async_function<'fut, A, R>(
+    fn call_async_function<A, R>(
         &self,
         name: impl AsRef<str>,
         args: A,
-    ) -> LocalBoxFuture<'fut, Result<R>>
+    ) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut,
+        R: FromLuaMulti<'lua> + 'lua,
     {
         match self.get(name.as_ref()) {
-            Ok(Value::Function(func)) => func.call_async(args),
-            Ok(val) => Box::pin(future::err(Error::RuntimeError(format!(
-                "attempt to call a {} value",
-                val.type_name()
-            )))),
+            Ok(Value::Function(func)) => {
+                let args = match args.into_lua_multi(self.0.lua) {
+                    Ok(args) => args,
+                    Err(e) => return Box::pin(future::err(e)),
+                };
+                Box::pin(async move { func.call_async(args).await })
+            }
+            Ok(val) => {
+                let type_name = val.type_name();
+                let msg = format!("attempt to call a {type_name} value");
+                Box::pin(future::err(Error::RuntimeError(msg)))
+            }
             Err(err) => Box::pin(future::err(err)),
         }
     }

src/userdata_impl.rs

@@ -1,6 +1,9 @@
+#![allow(clippy::await_holding_refcell_ref, clippy::await_holding_lock)]
+
 use std::any::TypeId;
 use std::cell::{Ref, RefCell, RefMut};
 use std::marker::PhantomData;
+use std::os::raw::c_int;
 use std::string::String as StdString;
 use std::sync::{Arc, Mutex, RwLock};
 
@@ -10,7 +13,7 @@ use crate::types::{Callback, MaybeSend};
 use crate::userdata::{
     AnyUserData, MetaMethod, UserData, UserDataCell, UserDataFields, UserDataMethods,
 };
-use crate::util::{check_stack, get_userdata, short_type_name, StackGuard};
+use crate::util::{get_userdata, short_type_name};
 use crate::value::{FromLua, FromLuaMulti, IntoLua, IntoLuaMulti, MultiValue, Value};
 
 #[cfg(not(feature = "send"))]
@@ -75,62 +78,63 @@ impl<'lua, T: 'static> UserDataRegistrar<'lua, T> {
         }
 
         Box::new(move |lua, mut args| {
-            let front = args.pop_front();
+            let front = args
+                .pop_front()
+                .ok_or_else(|| Error::from_lua_conversion("missing argument", "userdata", None));
+            let front = try_self_arg!(front);
             let call = |ud| {
                 // Self was at index 1, so we pass 2 here
                 let args = A::from_lua_multi_args(args, 2, Some(&name), lua)?;
                 method(lua, ud, args)?.into_lua_multi(lua)
             };
 
-            if let Some(front) = front {
-                let state = lua.state();
-                let userdata = try_self_arg!(AnyUserData::from_lua(front, lua));
-                unsafe {
-                    let _sg = StackGuard::new(state);
-                    check_stack(state, 2)?;
-
-                    let type_id = try_self_arg!(lua.push_userdata_ref(&userdata.0));
-                    match type_id {
-                        Some(id) if id == TypeId::of::<T>() => {
-                            let ud = try_self_arg!(get_userdata_ref::<T>(state));
-                            call(&ud)
-                        }
-                        #[cfg(not(feature = "send"))]
-                        Some(id) if id == TypeId::of::<Rc<RefCell<T>>>() => {
-                            let ud = try_self_arg!(get_userdata_ref::<Rc<RefCell<T>>>(state));
-                            let ud = try_self_arg!(ud.try_borrow(), Error::UserDataBorrowError);
-                            call(&ud)
-                        }
-                        Some(id) if id == TypeId::of::<Arc<Mutex<T>>>() => {
-                            let ud = try_self_arg!(get_userdata_ref::<Arc<Mutex<T>>>(state));
-                            let ud = try_self_arg!(ud.try_lock(), Error::UserDataBorrowError);
-                            call(&ud)
-                        }
-                        #[cfg(feature = "parking_lot")]
-                        Some(id) if id == TypeId::of::<Arc<parking_lot::Mutex<T>>>() => {
-                            let ud = get_userdata_ref::<Arc<parking_lot::Mutex<T>>>(state);
-                            let ud = try_self_arg!(ud);
-                            let ud = try_self_arg!(ud.try_lock().ok_or(Error::UserDataBorrowError));
-                            call(&ud)
-                        }
-                        Some(id) if id == TypeId::of::<Arc<RwLock<T>>>() => {
-                            let ud = try_self_arg!(get_userdata_ref::<Arc<RwLock<T>>>(state));
-                            let ud = try_self_arg!(ud.try_read(), Error::UserDataBorrowError);
-                            call(&ud)
-                        }
-                        #[cfg(feature = "parking_lot")]
-                        Some(id) if id == TypeId::of::<Arc<parking_lot::RwLock<T>>>() => {
-                            let ud = get_userdata_ref::<Arc<parking_lot::RwLock<T>>>(state);
-                            let ud = try_self_arg!(ud);
-                            let ud = try_self_arg!(ud.try_read().ok_or(Error::UserDataBorrowError));
-                            call(&ud)
-                        }
-                        _ => Err(Error::bad_self_argument(&name, Error::UserDataTypeMismatch)),
-                    }
-                }
-            } else {
-                let err = Error::from_lua_conversion("missing argument", "userdata", None);
-                Err(Error::bad_self_argument(&name, err))
+            let userdata = try_self_arg!(AnyUserData::from_lua(front, lua));
+            let (ref_thread, index) = (lua.ref_thread(), userdata.0.index);
+            match try_self_arg!(userdata.type_id()) {
+                Some(id) if id == TypeId::of::<T>() => unsafe {
+                    let ud = try_self_arg!(get_userdata_ref::<T>(ref_thread, index));
+                    call(&ud)
+                },
+                #[cfg(not(feature = "send"))]
+                Some(id) if id == TypeId::of::<Rc<T>>() => unsafe {
+                    let ud = try_self_arg!(get_userdata_ref::<Rc<T>>(ref_thread, index));
+                    call(&ud)
+                },
+                #[cfg(not(feature = "send"))]
+                Some(id) if id == TypeId::of::<Rc<RefCell<T>>>() => unsafe {
+                    let ud = try_self_arg!(get_userdata_ref::<Rc<RefCell<T>>>(ref_thread, index));
+                    let ud = try_self_arg!(ud.try_borrow(), Error::UserDataBorrowError);
+                    call(&ud)
+                },
+                Some(id) if id == TypeId::of::<Arc<T>>() => unsafe {
+                    let ud = try_self_arg!(get_userdata_ref::<Arc<T>>(ref_thread, index));
+                    call(&ud)
+                },
+                Some(id) if id == TypeId::of::<Arc<Mutex<T>>>() => unsafe {
+                    let ud = try_self_arg!(get_userdata_ref::<Arc<Mutex<T>>>(ref_thread, index));
+                    let ud = try_self_arg!(ud.try_lock(), Error::UserDataBorrowError);
+                    call(&ud)
+                },
+                #[cfg(feature = "parking_lot")]
+                Some(id) if id == TypeId::of::<Arc<parking_lot::Mutex<T>>>() => unsafe {
+                    let ud = get_userdata_ref::<Arc<parking_lot::Mutex<T>>>(ref_thread, index);
+                    let ud = try_self_arg!(ud);
+                    let ud = try_self_arg!(ud.try_lock().ok_or(Error::UserDataBorrowError));
+                    call(&ud)
+                },
+                Some(id) if id == TypeId::of::<Arc<RwLock<T>>>() => unsafe {
+                    let ud = try_self_arg!(get_userdata_ref::<Arc<RwLock<T>>>(ref_thread, index));
+                    let ud = try_self_arg!(ud.try_read(), Error::UserDataBorrowError);
+                    call(&ud)
+                },
+                #[cfg(feature = "parking_lot")]
+                Some(id) if id == TypeId::of::<Arc<parking_lot::RwLock<T>>>() => unsafe {
+                    let ud = get_userdata_ref::<Arc<parking_lot::RwLock<T>>>(ref_thread, index);
+                    let ud = try_self_arg!(ud);
+                    let ud = try_self_arg!(ud.try_read().ok_or(Error::UserDataBorrowError));
+                    call(&ud)
+                },
+                _ => Err(Error::bad_self_argument(&name, Error::UserDataTypeMismatch)),
             }
         })
     }
@@ -156,158 +160,258 @@ impl<'lua, T: 'static> UserDataRegistrar<'lua, T> {
             let mut method = method
                 .try_borrow_mut()
                 .map_err(|_| Error::RecursiveMutCallback)?;
-            let front = args.pop_front();
+            let front = args
+                .pop_front()
+                .ok_or_else(|| Error::from_lua_conversion("missing argument", "userdata", None));
+            let front = try_self_arg!(front);
             let call = |ud| {
                 // Self was at index 1, so we pass 2 here
                 let args = A::from_lua_multi_args(args, 2, Some(&name), lua)?;
                 method(lua, ud, args)?.into_lua_multi(lua)
             };
 
-            if let Some(front) = front {
-                let state = lua.state();
-                let userdata = try_self_arg!(AnyUserData::from_lua(front, lua));
-                unsafe {
-                    let _sg = StackGuard::new(state);
-                    check_stack(state, 2)?;
-
-                    let type_id = try_self_arg!(lua.push_userdata_ref(&userdata.0));
-                    match type_id {
-                        Some(id) if id == TypeId::of::<T>() => {
-                            let mut ud = try_self_arg!(get_userdata_mut::<T>(state));
-                            call(&mut ud)
-                        }
-                        #[cfg(not(feature = "send"))]
-                        Some(id) if id == TypeId::of::<Rc<RefCell<T>>>() => {
-                            let ud = try_self_arg!(get_userdata_mut::<Rc<RefCell<T>>>(state));
-                            let mut ud =
-                                try_self_arg!(ud.try_borrow_mut(), Error::UserDataBorrowMutError);
-                            call(&mut ud)
-                        }
-                        Some(id) if id == TypeId::of::<Arc<Mutex<T>>>() => {
-                            let ud = try_self_arg!(get_userdata_mut::<Arc<Mutex<T>>>(state));
-                            let mut ud =
-                                try_self_arg!(ud.try_lock(), Error::UserDataBorrowMutError);
-                            call(&mut ud)
-                        }
-                        #[cfg(feature = "parking_lot")]
-                        Some(id) if id == TypeId::of::<Arc<parking_lot::Mutex<T>>>() => {
-                            let ud = get_userdata_mut::<Arc<parking_lot::Mutex<T>>>(state);
-                            let ud = try_self_arg!(ud);
-                            let mut ud =
-                                try_self_arg!(ud.try_lock().ok_or(Error::UserDataBorrowMutError));
-                            call(&mut ud)
-                        }
-                        Some(id) if id == TypeId::of::<Arc<RwLock<T>>>() => {
-                            let ud = try_self_arg!(get_userdata_mut::<Arc<RwLock<T>>>(state));
-                            let mut ud =
-                                try_self_arg!(ud.try_write(), Error::UserDataBorrowMutError);
-                            call(&mut ud)
-                        }
-                        #[cfg(feature = "parking_lot")]
-                        Some(id) if id == TypeId::of::<Arc<parking_lot::RwLock<T>>>() => {
-                            let ud = get_userdata_mut::<Arc<parking_lot::RwLock<T>>>(state);
-                            let ud = try_self_arg!(ud);
-                            let mut ud =
-                                try_self_arg!(ud.try_write().ok_or(Error::UserDataBorrowMutError));
-                            call(&mut ud)
-                        }
-                        _ => Err(Error::bad_self_argument(&name, Error::UserDataTypeMismatch)),
-                    }
-                }
-            } else {
-                let err = Error::from_lua_conversion("missing argument", "userdata", None);
-                Err(Error::bad_self_argument(&name, err))
+            let userdata = try_self_arg!(AnyUserData::from_lua(front, lua));
+            let (ref_thread, index) = (lua.ref_thread(), userdata.0.index);
+            match try_self_arg!(userdata.type_id()) {
+                Some(id) if id == TypeId::of::<T>() => unsafe {
+                    let mut ud = try_self_arg!(get_userdata_mut::<T>(ref_thread, index));
+                    call(&mut ud)
+                },
+                #[cfg(not(feature = "send"))]
+                Some(id) if id == TypeId::of::<Rc<T>>() => Err(Error::UserDataBorrowMutError),
+                #[cfg(not(feature = "send"))]
+                Some(id) if id == TypeId::of::<Rc<RefCell<T>>>() => unsafe {
+                    let ud = try_self_arg!(get_userdata_mut::<Rc<RefCell<T>>>(ref_thread, index));
+                    let mut ud = try_self_arg!(ud.try_borrow_mut(), Error::UserDataBorrowMutError);
+                    call(&mut ud)
+                },
+                Some(id) if id == TypeId::of::<Arc<T>>() => Err(Error::UserDataBorrowMutError),
+                Some(id) if id == TypeId::of::<Arc<Mutex<T>>>() => unsafe {
+                    let ud = try_self_arg!(get_userdata_mut::<Arc<Mutex<T>>>(ref_thread, index));
+                    let mut ud = try_self_arg!(ud.try_lock(), Error::UserDataBorrowMutError);
+                    call(&mut ud)
+                },
+                #[cfg(feature = "parking_lot")]
+                Some(id) if id == TypeId::of::<Arc<parking_lot::Mutex<T>>>() => unsafe {
+                    let ud = get_userdata_mut::<Arc<parking_lot::Mutex<T>>>(ref_thread, index);
+                    let ud = try_self_arg!(ud);
+                    let mut ud = try_self_arg!(ud.try_lock().ok_or(Error::UserDataBorrowMutError));
+                    call(&mut ud)
+                },
+                Some(id) if id == TypeId::of::<Arc<RwLock<T>>>() => unsafe {
+                    let ud = try_self_arg!(get_userdata_mut::<Arc<RwLock<T>>>(ref_thread, index));
+                    let mut ud = try_self_arg!(ud.try_write(), Error::UserDataBorrowMutError);
+                    call(&mut ud)
+                },
+                #[cfg(feature = "parking_lot")]
+                Some(id) if id == TypeId::of::<Arc<parking_lot::RwLock<T>>>() => unsafe {
+                    let ud = get_userdata_mut::<Arc<parking_lot::RwLock<T>>>(ref_thread, index);
+                    let ud = try_self_arg!(ud);
+                    let mut ud = try_self_arg!(ud.try_write().ok_or(Error::UserDataBorrowMutError));
+                    call(&mut ud)
+                },
+                _ => Err(Error::bad_self_argument(&name, Error::UserDataTypeMismatch)),
             }
         })
     }
 
     #[cfg(feature = "async")]
-    fn box_async_method<M, A, MR, R>(name: &str, method: M) -> AsyncCallback<'lua, 'static>
+    fn box_async_method<'s, M, A, MR, R>(name: &str, method: M) -> AsyncCallback<'lua, 'static>
     where
-        T: Clone,
-        M: Fn(&'lua Lua, T, A) -> MR + MaybeSend + 'static,
+        'lua: 's,
+        T: 'static,
+        M: Fn(&'lua Lua, &'s T, A) -> MR + MaybeSend + 'static,
         A: FromLuaMulti<'lua>,
-        MR: Future<Output = Result<R>> + 'lua,
+        MR: Future<Output = Result<R>> + 's,
         R: IntoLuaMulti<'lua>,
     {
         let name = get_function_name::<T>(name);
-        macro_rules! try_self_arg {
-            ($res:expr) => {
-                $res.map_err(|err| Error::bad_self_argument(&name, err))?
-            };
-            ($res:expr, $err:expr) => {
-                $res.map_err(|_| Error::bad_self_argument(&name, $err))?
-            };
-        }
+        let method = Arc::new(method);
 
         Box::new(move |lua, mut args| {
-            let front = args.pop_front();
-            let call = |ud| {
-                // Self was at index 1, so we pass 2 here
-                let args = A::from_lua_multi_args(args, 2, Some(&name), lua)?;
-                Ok(method(lua, ud, args))
-            };
-
-            let fut_res = || {
-                if let Some(front) = front {
-                    let state = lua.state();
-                    let userdata = AnyUserData::from_lua(front, lua)?;
-                    unsafe {
-                        let _sg = StackGuard::new(state);
-                        check_stack(state, 2)?;
-
-                        let type_id = try_self_arg!(lua.push_userdata_ref(&userdata.0));
-                        match type_id {
-                            Some(id) if id == TypeId::of::<T>() => {
-                                let ud = get_userdata_ref::<T>(state)?;
-                                call(ud.clone())
-                            }
-                            #[cfg(not(feature = "send"))]
-                            Some(id) if id == TypeId::of::<Rc<RefCell<T>>>() => {
-                                let ud = try_self_arg!(get_userdata_ref::<Rc<RefCell<T>>>(state));
-                                let ud = try_self_arg!(ud.try_borrow(), Error::UserDataBorrowError);
-                                call(ud.clone())
-                            }
-                            Some(id) if id == TypeId::of::<Arc<Mutex<T>>>() => {
-                                let ud = try_self_arg!(get_userdata_ref::<Arc<Mutex<T>>>(state));
-                                let ud = try_self_arg!(ud.try_lock(), Error::UserDataBorrowError);
-                                call(ud.clone())
-                            }
-                            #[cfg(feature = "parking_lot")]
-                            Some(id) if id == TypeId::of::<Arc<parking_lot::Mutex<T>>>() => {
-                                let ud = get_userdata_ref::<Arc<parking_lot::Mutex<T>>>(state);
-                                let ud = try_self_arg!(ud);
-                                let ud =
-                                    try_self_arg!(ud.try_lock().ok_or(Error::UserDataBorrowError));
-                                call(ud.clone())
-                            }
-                            Some(id) if id == TypeId::of::<Arc<RwLock<T>>>() => {
-                                let ud = try_self_arg!(get_userdata_ref::<Arc<RwLock<T>>>(state));
-                                let ud = try_self_arg!(ud.try_read(), Error::UserDataBorrowError);
-                                call(ud.clone())
-                            }
-                            #[cfg(feature = "parking_lot")]
-                            Some(id) if id == TypeId::of::<Arc<parking_lot::RwLock<T>>>() => {
-                                let ud = get_userdata_ref::<Arc<parking_lot::RwLock<T>>>(state);
-                                let ud = try_self_arg!(ud);
-                                let ud =
-                                    try_self_arg!(ud.try_read().ok_or(Error::UserDataBorrowError));
-                                call(ud.clone())
-                            }
-                            _ => Err(Error::bad_self_argument(&name, Error::UserDataTypeMismatch)),
-                        }
-                    }
-                } else {
-                    let err = Error::from_lua_conversion("missing argument", "userdata", None);
-                    Err(Error::bad_self_argument(&name, err))
-                }
-            };
-            match fut_res() {
-                Ok(fut) => {
-                    Box::pin(fut.and_then(move |ret| future::ready(ret.into_lua_multi(lua))))
-                }
-                Err(e) => Box::pin(future::err(e)),
+            let name = name.clone();
+            let method = method.clone();
+            macro_rules! try_self_arg {
+                ($res:expr) => {
+                    $res.map_err(|err| Error::bad_self_argument(&name, err))?
+                };
+                ($res:expr, $err:expr) => {
+                    $res.map_err(|_| Error::bad_self_argument(&name, $err))?
+                };
             }
+
+            Box::pin(async move {
+                let front = args.pop_front().ok_or_else(|| {
+                    Error::from_lua_conversion("missing argument", "userdata", None)
+                });
+                let front = try_self_arg!(front);
+                let userdata: AnyUserData = try_self_arg!(AnyUserData::from_lua(front, lua));
+                let (ref_thread, index) = (lua.ref_thread(), userdata.0.index);
+                match try_self_arg!(userdata.type_id()) {
+                    Some(id) if id == TypeId::of::<T>() => unsafe {
+                        let ud = try_self_arg!(get_userdata_ref::<T>(ref_thread, index));
+                        let ud = std::mem::transmute::<&T, &T>(&ud);
+                        // Self was at index 1, so we pass 2 here
+                        let args = A::from_lua_multi_args(args, 2, Some(&name), lua)?;
+                        method(lua, ud, args).await?.into_lua_multi(lua)
+                    },
+                    #[cfg(not(feature = "send"))]
+                    Some(id) if id == TypeId::of::<Rc<T>>() => unsafe {
+                        let ud = try_self_arg!(get_userdata_ref::<Rc<T>>(ref_thread, index));
+                        let ud = std::mem::transmute::<&T, &T>(&ud);
+                        let args = A::from_lua_multi_args(args, 2, Some(&name), lua)?;
+                        method(lua, ud, args).await?.into_lua_multi(lua)
+                    },
+                    #[cfg(not(feature = "send"))]
+                    Some(id) if id == TypeId::of::<Rc<RefCell<T>>>() => unsafe {
+                        let ud =
+                            try_self_arg!(get_userdata_ref::<Rc<RefCell<T>>>(ref_thread, index));
+                        let ud = try_self_arg!(ud.try_borrow(), Error::UserDataBorrowError);
+                        let ud = std::mem::transmute::<&T, &T>(&ud);
+                        let args = A::from_lua_multi_args(args, 2, Some(&name), lua)?;
+                        method(lua, ud, args).await?.into_lua_multi(lua)
+                    },
+                    Some(id) if id == TypeId::of::<Arc<T>>() => unsafe {
+                        let ud = try_self_arg!(get_userdata_ref::<Arc<T>>(ref_thread, index));
+                        let ud = std::mem::transmute::<&T, &T>(&ud);
+                        let args = A::from_lua_multi_args(args, 2, Some(&name), lua)?;
+                        method(lua, ud, args).await?.into_lua_multi(lua)
+                    },
+                    Some(id) if id == TypeId::of::<Arc<Mutex<T>>>() => unsafe {
+                        let ud =
+                            try_self_arg!(get_userdata_ref::<Arc<Mutex<T>>>(ref_thread, index));
+                        let ud = try_self_arg!(ud.try_lock(), Error::UserDataBorrowError);
+                        let ud = std::mem::transmute::<&T, &T>(&ud);
+                        let args = A::from_lua_multi_args(args, 2, Some(&name), lua)?;
+                        method(lua, ud, args).await?.into_lua_multi(lua)
+                    },
+                    #[cfg(feature = "parking_lot")]
+                    Some(id) if id == TypeId::of::<Arc<parking_lot::Mutex<T>>>() => unsafe {
+                        let ud = get_userdata_ref::<Arc<parking_lot::Mutex<T>>>(ref_thread, index);
+                        let ud = try_self_arg!(ud);
+                        let ud = try_self_arg!(ud.try_lock().ok_or(Error::UserDataBorrowError));
+                        let ud = std::mem::transmute::<&T, &T>(&ud);
+                        let args = A::from_lua_multi_args(args, 2, Some(&name), lua)?;
+                        method(lua, ud, args).await?.into_lua_multi(lua)
+                    },
+                    Some(id) if id == TypeId::of::<Arc<RwLock<T>>>() => unsafe {
+                        let ud =
+                            try_self_arg!(get_userdata_ref::<Arc<RwLock<T>>>(ref_thread, index));
+                        let ud = try_self_arg!(ud.try_read(), Error::UserDataBorrowError);
+                        let ud = std::mem::transmute::<&T, &T>(&ud);
+                        let args = A::from_lua_multi_args(args, 2, Some(&name), lua)?;
+                        method(lua, ud, args).await?.into_lua_multi(lua)
+                    },
+                    #[cfg(feature = "parking_lot")]
+                    Some(id) if id == TypeId::of::<Arc<parking_lot::RwLock<T>>>() => unsafe {
+                        let ud = get_userdata_ref::<Arc<parking_lot::RwLock<T>>>(ref_thread, index);
+                        let ud = try_self_arg!(ud);
+                        let ud = try_self_arg!(ud.try_read().ok_or(Error::UserDataBorrowError));
+                        let ud = std::mem::transmute::<&T, &T>(&ud);
+                        let args = A::from_lua_multi_args(args, 2, Some(&name), lua)?;
+                        method(lua, ud, args).await?.into_lua_multi(lua)
+                    },
+                    _ => Err(Error::bad_self_argument(&name, Error::UserDataTypeMismatch)),
+                }
+            })
+        })
+    }
+
+    #[cfg(feature = "async")]
+    fn box_async_method_mut<'s, M, A, MR, R>(name: &str, method: M) -> AsyncCallback<'lua, 'static>
+    where
+        'lua: 's,
+        T: 'static,
+        M: Fn(&'lua Lua, &'s mut T, A) -> MR + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        MR: Future<Output = Result<R>> + 's,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = get_function_name::<T>(name);
+        let method = Arc::new(method);
+
+        Box::new(move |lua, mut args| {
+            let name = name.clone();
+            let method = method.clone();
+            macro_rules! try_self_arg {
+                ($res:expr) => {
+                    $res.map_err(|err| Error::bad_self_argument(&name, err))?
+                };
+                ($res:expr, $err:expr) => {
+                    $res.map_err(|_| Error::bad_self_argument(&name, $err))?
+                };
+            }
+
+            Box::pin(async move {
+                let front = args.pop_front().ok_or_else(|| {
+                    Error::from_lua_conversion("missing argument", "userdata", None)
+                });
+                let front = try_self_arg!(front);
+                let userdata: AnyUserData = try_self_arg!(AnyUserData::from_lua(front, lua));
+                let (ref_thread, index) = (lua.ref_thread(), userdata.0.index);
+                match try_self_arg!(userdata.type_id()) {
+                    Some(id) if id == TypeId::of::<T>() => unsafe {
+                        let mut ud = try_self_arg!(get_userdata_mut::<T>(ref_thread, index));
+                        let ud = std::mem::transmute::<&mut T, &mut T>(&mut ud);
+                        // Self was at index 1, so we pass 2 here
+                        let args = A::from_lua_multi_args(args, 2, Some(&name), lua)?;
+                        method(lua, ud, args).await?.into_lua_multi(lua)
+                    },
+                    #[cfg(not(feature = "send"))]
+                    Some(id) if id == TypeId::of::<Rc<RefCell<T>>>() => {
+                        Err(Error::UserDataBorrowMutError)
+                    }
+                    #[cfg(not(feature = "send"))]
+                    Some(id) if id == TypeId::of::<Rc<RefCell<T>>>() => unsafe {
+                        let ud =
+                            try_self_arg!(get_userdata_mut::<Rc<RefCell<T>>>(ref_thread, index));
+                        let mut ud =
+                            try_self_arg!(ud.try_borrow_mut(), Error::UserDataBorrowMutError);
+                        let ud = std::mem::transmute::<&mut T, &mut T>(&mut ud);
+                        let args = A::from_lua_multi_args(args, 2, Some(&name), lua)?;
+                        method(lua, ud, args).await?.into_lua_multi(lua)
+                    },
+                    #[cfg(not(feature = "send"))]
+                    Some(id) if id == TypeId::of::<Arc<T>>() => Err(Error::UserDataBorrowMutError),
+                    Some(id) if id == TypeId::of::<Arc<Mutex<T>>>() => unsafe {
+                        let ud =
+                            try_self_arg!(get_userdata_mut::<Arc<Mutex<T>>>(ref_thread, index));
+                        let mut ud = try_self_arg!(ud.try_lock(), Error::UserDataBorrowMutError);
+                        let ud = std::mem::transmute::<&mut T, &mut T>(&mut ud);
+                        let args = A::from_lua_multi_args(args, 2, Some(&name), lua)?;
+                        method(lua, ud, args).await?.into_lua_multi(lua)
+                    },
+                    #[cfg(feature = "parking_lot")]
+                    Some(id) if id == TypeId::of::<Arc<parking_lot::Mutex<T>>>() => unsafe {
+                        let ud = get_userdata_mut::<Arc<parking_lot::Mutex<T>>>(ref_thread, index);
+                        let ud = try_self_arg!(ud);
+                        let mut ud =
+                            try_self_arg!(ud.try_lock().ok_or(Error::UserDataBorrowMutError));
+                        let ud = std::mem::transmute::<&mut T, &mut T>(&mut ud);
+                        let args = A::from_lua_multi_args(args, 2, Some(&name), lua)?;
+                        method(lua, ud, args).await?.into_lua_multi(lua)
+                    },
+                    Some(id) if id == TypeId::of::<Arc<RwLock<T>>>() => unsafe {
+                        let ud =
+                            try_self_arg!(get_userdata_mut::<Arc<RwLock<T>>>(ref_thread, index));
+                        let mut ud = try_self_arg!(ud.try_write(), Error::UserDataBorrowMutError);
+                        let ud = std::mem::transmute::<&mut T, &mut T>(&mut ud);
+                        let args = A::from_lua_multi_args(args, 2, Some(&name), lua)?;
+                        method(lua, ud, args).await?.into_lua_multi(lua)
+                    },
+                    #[cfg(feature = "parking_lot")]
+                    Some(id) if id == TypeId::of::<Arc<parking_lot::RwLock<T>>>() => unsafe {
+                        let ud = get_userdata_mut::<Arc<parking_lot::RwLock<T>>>(ref_thread, index);
+                        let ud = try_self_arg!(ud);
+                        let mut ud =
+                            try_self_arg!(ud.try_write().ok_or(Error::UserDataBorrowMutError));
+                        let ud = std::mem::transmute::<&mut T, &mut T>(&mut ud);
+                        let args = A::from_lua_multi_args(args, 2, Some(&name), lua)?;
+                        method(lua, ud, args).await?.into_lua_multi(lua)
+                    },
+                    _ => Err(Error::bad_self_argument(&name, Error::UserDataTypeMismatch)),
+                }
+            })
         })
     }
 
@@ -500,12 +604,13 @@ impl<'lua, T: 'static> UserDataMethods<'lua, T> for UserDataRegistrar<'lua, T> {
     }
 
     #[cfg(feature = "async")]
-    fn add_async_method<M, A, MR, R>(&mut self, name: impl AsRef<str>, method: M)
+    fn add_async_method<'s, M, A, MR, R>(&mut self, name: impl AsRef<str>, method: M)
     where
-        T: Clone,
-        M: Fn(&'lua Lua, T, A) -> MR + MaybeSend + 'static,
+        'lua: 's,
+        T: 'static,
+        M: Fn(&'lua Lua, &'s T, A) -> MR + MaybeSend + 'static,
         A: FromLuaMulti<'lua>,
-        MR: Future<Output = Result<R>> + 'lua,
+        MR: Future<Output = Result<R>> + 's,
         R: IntoLuaMulti<'lua>,
     {
         let name = name.as_ref();
@@ -513,6 +618,21 @@ impl<'lua, T: 'static> UserDataMethods<'lua, T> for UserDataRegistrar<'lua, T> {
             .push((name.into(), Self::box_async_method(name, method)));
     }
 
+    #[cfg(feature = "async")]
+    fn add_async_method_mut<'s, M, A, MR, R>(&mut self, name: impl AsRef<str>, method: M)
+    where
+        'lua: 's,
+        T: 'static,
+        M: Fn(&'lua Lua, &'s mut T, A) -> MR + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        MR: Future<Output = Result<R>> + 's,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = name.as_ref();
+        self.async_methods
+            .push((name.into(), Self::box_async_method_mut(name, method)));
+    }
+
     fn add_function<F, A, R>(&mut self, name: impl AsRef<str>, function: F)
     where
         F: Fn(&'lua Lua, A) -> Result<R> + MaybeSend + 'static,
@@ -571,12 +691,13 @@ impl<'lua, T: 'static> UserDataMethods<'lua, T> for UserDataRegistrar<'lua, T> {
     }
 
     #[cfg(all(feature = "async", not(any(feature = "lua51", feature = "luau"))))]
-    fn add_async_meta_method<M, A, MR, R>(&mut self, name: impl AsRef<str>, method: M)
+    fn add_async_meta_method<'s, M, A, MR, R>(&mut self, name: impl AsRef<str>, method: M)
     where
-        T: Clone,
-        M: Fn(&'lua Lua, T, A) -> MR + MaybeSend + 'static,
+        'lua: 's,
+        T: 'static,
+        M: Fn(&'lua Lua, &'s T, A) -> MR + MaybeSend + 'static,
         A: FromLuaMulti<'lua>,
-        MR: Future<Output = Result<R>> + 'lua,
+        MR: Future<Output = Result<R>> + 's,
         R: IntoLuaMulti<'lua>,
     {
         let name = name.as_ref();
@@ -584,6 +705,21 @@ impl<'lua, T: 'static> UserDataMethods<'lua, T> for UserDataRegistrar<'lua, T> {
             .push((name.into(), Self::box_async_method(name, method)));
     }
 
+    #[cfg(all(feature = "async", not(any(feature = "lua51", feature = "luau"))))]
+    fn add_async_meta_method_mut<'s, M, A, MR, R>(&mut self, name: impl AsRef<str>, method: M)
+    where
+        'lua: 's,
+        T: 'static,
+        M: Fn(&'lua Lua, &'s mut T, A) -> MR + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        MR: Future<Output = Result<R>> + 's,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = name.as_ref();
+        self.async_meta_methods
+            .push((name.into(), Self::box_async_method_mut(name, method)));
+    }
+
     fn add_meta_function<F, A, R>(&mut self, name: impl AsRef<str>, function: F)
     where
         F: Fn(&'lua Lua, A) -> Result<R> + MaybeSend + 'static,
@@ -632,13 +768,16 @@ impl<'lua, T: 'static> UserDataMethods<'lua, T> for UserDataRegistrar<'lua, T> {
 }
 
 #[inline]
-unsafe fn get_userdata_ref<'a, T>(state: *mut ffi::lua_State) -> Result<Ref<'a, T>> {
-    (*get_userdata::<UserDataCell<T>>(state, -1)).try_borrow()
+unsafe fn get_userdata_ref<'a, T>(state: *mut ffi::lua_State, index: c_int) -> Result<Ref<'a, T>> {
+    (*get_userdata::<UserDataCell<T>>(state, index)).try_borrow()
 }
 
 #[inline]
-unsafe fn get_userdata_mut<'a, T>(state: *mut ffi::lua_State) -> Result<RefMut<'a, T>> {
-    (*get_userdata::<UserDataCell<T>>(state, -1)).try_borrow_mut()
+unsafe fn get_userdata_mut<'a, T>(
+    state: *mut ffi::lua_State,
+    index: c_int,
+) -> Result<RefMut<'a, T>> {
+    (*get_userdata::<UserDataCell<T>>(state, index)).try_borrow_mut()
 }
 
 macro_rules! lua_userdata_impl {
@@ -659,8 +798,12 @@ macro_rules! lua_userdata_impl {
     };
 }
 
+#[cfg(not(feature = "send"))]
+lua_userdata_impl!(Rc<T>);
 #[cfg(not(feature = "send"))]
 lua_userdata_impl!(Rc<RefCell<T>>);
+
+lua_userdata_impl!(Arc<T>);
 lua_userdata_impl!(Arc<Mutex<T>>);
 lua_userdata_impl!(Arc<RwLock<T>>);
 #[cfg(feature = "parking_lot")]

src/util/mod.rs

@@ -359,6 +359,7 @@ pub unsafe fn take_userdata<T>(state: *mut ffi::lua_State) -> T {
 
 // Pushes the userdata and attaches a metatable with __gc method.
 // Internally uses 3 stack spaces, does not call checkstack.
+#[inline]
 pub unsafe fn push_gc_userdata<T: Any>(
     state: *mut ffi::lua_State,
     t: T,
@@ -398,7 +399,7 @@ pub unsafe fn get_gc_userdata<T: Any>(
 }
 
 unsafe extern "C" fn lua_error_impl(state: *mut ffi::lua_State) -> c_int {
-    ffi::lua_error(state);
+    ffi::lua_error(state)
 }
 
 unsafe extern "C" fn lua_isfunction_impl(state: *mut ffi::lua_State) -> c_int {
@@ -628,6 +629,7 @@ pub unsafe extern "C" fn userdata_destructor<T>(state: *mut ffi::lua_State) -> c
 // This function uses some of the bottom of the stack for error handling, the given callback will be
 // given the number of arguments available as an argument, and should return the number of returns
 // as normal, but cannot assume that the arguments available start at 0.
+#[inline]
 pub unsafe fn callback_error<F, R>(state: *mut ffi::lua_State, f: F) -> R
 where
     F: FnOnce(c_int) -> Result<R>,
@@ -854,6 +856,7 @@ pub unsafe fn init_gc_metatable<T: Any>(
     Ok(())
 }
 
+#[inline]
 pub unsafe fn get_gc_metatable<T: Any>(state: *mut ffi::lua_State) {
     let type_id = TypeId::of::<T>();
     let ref_addr =

src/value.rs

@@ -44,7 +44,7 @@ pub enum Value<'lua> {
     /// A Luau vector.
     #[cfg(any(feature = "luau", doc))]
     #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
-    Vector(f32, f32, f32),
+    Vector(crate::types::Vector),
     /// An interned string, managed by Lua.
     ///
     /// Unlike Rust strings, Lua strings may not be valid UTF-8.
@@ -79,7 +79,7 @@ impl<'lua> Value<'lua> {
             Value::Integer(_) => "integer",
             Value::Number(_) => "number",
             #[cfg(feature = "luau")]
-            Value::Vector(_, _, _) => "vector",
+            Value::Vector(_) => "vector",
             Value::String(_) => "string",
             Value::Table(_) => "table",
             Value::Function(_) => "function",
@@ -116,18 +116,14 @@ impl<'lua> Value<'lua> {
     /// Typically this function is used only for hashing and debug information.
     #[inline]
     pub fn to_pointer(&self) -> *const c_void {
-        unsafe {
-            match self {
-                Value::LightUserData(ud) => ud.0,
-                Value::Table(t) => t.to_pointer(),
-                Value::String(s) => s.to_pointer(),
-                Value::Function(Function(r))
-                | Value::Thread(Thread(r))
-                | Value::UserData(AnyUserData(r)) => {
-                    ffi::lua_topointer(r.lua.ref_thread(), r.index)
-                }
-                _ => ptr::null(),
-            }
+        match self {
+            Value::LightUserData(ud) => ud.0,
+            Value::Table(Table(r))
+            | Value::String(String(r))
+            | Value::Function(Function(r))
+            | Value::Thread(Thread(r))
+            | Value::UserData(AnyUserData(r)) => r.to_pointer(),
+            _ => ptr::null(),
         }
     }
 
@@ -143,7 +139,7 @@ impl<'lua> Value<'lua> {
             Value::Integer(i) => Ok(i.to_string()),
             Value::Number(n) => Ok(n.to_string()),
             #[cfg(feature = "luau")]
-            Value::Vector(x, y, z) => Ok(format!("vector({x}, {y}, {z})")),
+            Value::Vector(v) => Ok(v.to_string()),
             Value::String(s) => Ok(s.to_str()?.to_string()),
             Value::Table(Table(r))
             | Value::Function(Function(r))
@@ -218,7 +214,7 @@ impl<'lua> Value<'lua> {
             Value::Integer(i) => write!(fmt, "{i}"),
             Value::Number(n) => write!(fmt, "{n}"),
             #[cfg(feature = "luau")]
-            Value::Vector(x, y, z) => write!(fmt, "vector({x}, {y}, {z})"),
+            Value::Vector(v) => write!(fmt, "{v}"),
             Value::String(s) => write!(fmt, "{s:?}"),
             Value::Table(t) if recursive && !visited.contains(&t.to_pointer()) => {
                 t.fmt_pretty(fmt, ident, visited)
@@ -249,7 +245,7 @@ impl fmt::Debug for Value<'_> {
             Value::Integer(i) => write!(fmt, "Integer({i})"),
             Value::Number(n) => write!(fmt, "Number({n})"),
             #[cfg(feature = "luau")]
-            Value::Vector(x, y, z) => write!(fmt, "Vector({x}, {y}, {z})"),
+            Value::Vector(v) => write!(fmt, "{v:?}"),
             Value::String(s) => write!(fmt, "String({s:?})"),
             Value::Table(t) => write!(fmt, "{t:?}"),
             Value::Function(f) => write!(fmt, "{f:?}"),
@@ -271,7 +267,7 @@ impl<'lua> PartialEq for Value<'lua> {
             (Value::Number(a), Value::Integer(b)) => *a == *b as Number,
             (Value::Number(a), Value::Number(b)) => *a == *b,
             #[cfg(feature = "luau")]
-            (Value::Vector(x1, y1, z1), Value::Vector(x2, y2, z2)) => (x1, y1, z1) == (x2, y2, z2),
+            (Value::Vector(v1), Value::Vector(v2)) => v1 == v2,
             (Value::String(a), Value::String(b)) => a == b,
             (Value::Table(a), Value::Table(b)) => a == b,
             (Value::Function(a), Value::Function(b)) => a == b,
@@ -303,7 +299,7 @@ impl<'lua> Serialize for Value<'lua> {
                 .serialize_i64((*i).try_into().expect("cannot convert Lua Integer to i64")),
             Value::Number(n) => serializer.serialize_f64(*n),
             #[cfg(feature = "luau")]
-            Value::Vector(x, y, z) => (x, y, z).serialize(serializer),
+            Value::Vector(v) => v.serialize(serializer),
             Value::String(s) => s.serialize(serializer),
             Value::Table(t) => t.serialize(serializer),
             Value::UserData(ud) => ud.serialize(serializer),

tests/async.rs

@@ -1,6 +1,5 @@
 #![cfg(feature = "async")]
 
-use std::sync::atomic::{AtomicU64, Ordering};
 use std::sync::{Arc, Mutex};
 use std::time::Duration;
 
@@ -361,19 +360,18 @@ async fn test_async_thread_pool() -> Result<()> {
 
 #[tokio::test]
 async fn test_async_userdata() -> Result<()> {
-    #[derive(Clone)]
-    struct MyUserData(Arc<AtomicU64>);
+    struct MyUserData(u64);
 
     impl UserData for MyUserData {
         fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
             methods.add_async_method("get_value", |_, data, ()| async move {
                 Delay::new(Duration::from_millis(10)).await;
-                Ok(data.0.load(Ordering::Relaxed))
+                Ok(data.0)
             });
 
-            methods.add_async_method("set_value", |_, data, n| async move {
+            methods.add_async_method_mut("set_value", |_, data, n| async move {
                 Delay::new(Duration::from_millis(10)).await;
-                data.0.store(n, Ordering::Relaxed);
+                data.0 = n;
                 Ok(())
             });
 
@@ -384,7 +382,7 @@ async fn test_async_userdata() -> Result<()> {
 
             #[cfg(not(any(feature = "lua51", feature = "luau")))]
             methods.add_async_meta_method(mlua::MetaMethod::Call, |_, data, ()| async move {
-                let n = data.0.load(Ordering::Relaxed);
+                let n = data.0;
                 Delay::new(Duration::from_millis(n)).await;
                 Ok(format!("elapsed:{}ms", n))
             });
@@ -395,23 +393,24 @@ async fn test_async_userdata() -> Result<()> {
                 |_, data, key: String| async move {
                     Delay::new(Duration::from_millis(10)).await;
                     match key.as_str() {
-                        "ms" => Ok(Some(data.0.load(Ordering::Relaxed) as f64)),
-                        "s" => Ok(Some((data.0.load(Ordering::Relaxed) as f64) / 1000.0)),
+                        "ms" => Ok(Some(data.0 as f64)),
+                        "s" => Ok(Some((data.0 as f64) / 1000.0)),
                         _ => Ok(None),
                     }
                 },
             );
 
             #[cfg(not(any(feature = "lua51", feature = "luau")))]
-            methods.add_async_meta_method(
+            methods.add_async_meta_method_mut(
                 mlua::MetaMethod::NewIndex,
                 |_, data, (key, value): (String, f64)| async move {
                     Delay::new(Duration::from_millis(10)).await;
                     match key.as_str() {
-                        "ms" => Ok(data.0.store(value as u64, Ordering::Relaxed)),
-                        "s" => Ok(data.0.store((value * 1000.0) as u64, Ordering::Relaxed)),
-                        _ => Err(Error::external(format!("key '{}' not found", key))),
+                        "ms" => data.0 = value as u64,
+                        "s" => data.0 = (value * 1000.0) as u64,
+                        _ => return Err(Error::external(format!("key '{}' not found", key))),
                     }
+                    Ok(())
                 },
             );
         }
@@ -420,7 +419,7 @@ async fn test_async_userdata() -> Result<()> {
     let lua = Lua::new();
     let globals = lua.globals();
 
-    let userdata = lua.create_userdata(MyUserData(Arc::new(AtomicU64::new(11))))?;
+    let userdata = lua.create_userdata(MyUserData(11))?;
     globals.set("userdata", userdata.clone())?;
 
     lua.load(

tests/compile.rs

@@ -15,7 +15,11 @@ fn test_compilation() {
     t.compile_fail("tests/compile/static_callback_args.rs");
 
     #[cfg(feature = "async")]
-    t.compile_fail("tests/compile/async_nonstatic_userdata.rs");
+    {
+        t.compile_fail("tests/compile/async_any_userdata_method.rs");
+        t.compile_fail("tests/compile/async_nonstatic_userdata.rs");
+        t.compile_fail("tests/compile/async_userdata_method.rs");
+    }
 
     #[cfg(feature = "send")]
     t.compile_fail("tests/compile/non_send.rs");

tests/compile/async_any_userdata_method.rs

@@ -0,0 +1,14 @@
+use mlua::{UserDataMethods, Lua};
+
+fn main() {
+    let lua = Lua::new();
+
+    lua.register_userdata_type::<String>(|reg| {
+        let s = String::new();
+        let mut s = &s;
+        reg.add_async_method("t", |_, this: &String, ()| async {
+            s = this;
+            Ok(())
+        });
+    }).unwrap();
+}

tests/compile/async_any_userdata_method.stderr

@@ -0,0 +1,81 @@
+error: lifetime may not live long enough
+  --> tests/compile/async_any_userdata_method.rs:9:58
+   |
+9  |           reg.add_async_method("t", |_, this: &String, ()| async {
+   |  ___________________________________----------------------_^
+   | |                                   |                    |
+   | |                                   |                    return type of closure `[async block@$DIR/tests/compile/async_any_userdata_method.rs:9:58: 12:10]` contains a lifetime `'2`
+   | |                                   lifetime `'1` represents this closure's body
+10 | |             s = this;
+11 | |             Ok(())
+12 | |         });
+   | |_________^ returning this value requires that `'1` must outlive `'2`
+   |
+   = note: closure implements `Fn`, so references to captured variables can't escape the closure
+
+error[E0596]: cannot borrow `s` as mutable, as it is a captured variable in a `Fn` closure
+  --> tests/compile/async_any_userdata_method.rs:9:58
+   |
+9  |           reg.add_async_method("t", |_, this: &String, ()| async {
+   |  __________________________________________________________^
+10 | |             s = this;
+   | |             - mutable borrow occurs due to use of `s` in closure
+11 | |             Ok(())
+12 | |         });
+   | |_________^ cannot borrow as mutable
+
+error[E0597]: `s` does not live long enough
+  --> tests/compile/async_any_userdata_method.rs:8:21
+   |
+8  |           let mut s = &s;
+   |                       ^^ borrowed value does not live long enough
+9  | /         reg.add_async_method("t", |_, this: &String, ()| async {
+10 | |             s = this;
+11 | |             Ok(())
+12 | |         });
+   | |__________- argument requires that `s` is borrowed for `'static`
+13 |       }).unwrap();
+   |       - `s` dropped here while still borrowed
+
+error[E0521]: borrowed data escapes outside of closure
+  --> tests/compile/async_any_userdata_method.rs:9:9
+   |
+6  |       lua.register_userdata_type::<String>(|reg| {
+   |                                             ---
+   |                                             |
+   |                                             `reg` is a reference that is only valid in the closure body
+   |                                             has type `&mut LuaUserDataRegistrar<'1, std::string::String>`
+...
+9  | /         reg.add_async_method("t", |_, this: &String, ()| async {
+10 | |             s = this;
+11 | |             Ok(())
+12 | |         });
+   | |          ^
+   | |          |
+   | |__________`reg` escapes the closure body here
+   |            argument requires that `'1` must outlive `'static`
+   |
+   = note: requirement occurs because of a mutable reference to `LuaUserDataRegistrar<'_, std::string::String>`
+   = note: mutable references are invariant over their type parameter
+   = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance
+
+error[E0373]: closure may outlive the current function, but it borrows `s`, which is owned by the current function
+  --> tests/compile/async_any_userdata_method.rs:9:35
+   |
+9  |         reg.add_async_method("t", |_, this: &String, ()| async {
+   |                                   ^^^^^^^^^^^^^^^^^^^^^^ may outlive borrowed value `s`
+10 |             s = this;
+   |             - `s` is borrowed here
+   |
+note: function requires argument type to outlive `'static`
+  --> tests/compile/async_any_userdata_method.rs:9:9
+   |
+9  | /         reg.add_async_method("t", |_, this: &String, ()| async {
+10 | |             s = this;
+11 | |             Ok(())
+12 | |         });
+   | |__________^
+help: to force the closure to take ownership of `s` (and any other referenced variables), use the `move` keyword
+   |
+9  |         reg.add_async_method("t", move |_, this: &String, ()| async {
+   |                                   ++++

tests/compile/async_nonstatic_userdata.stderr

@@ -4,11 +4,8 @@ error: lifetime may not live long enough
 7  |       impl<'a> UserData for MyUserData<'a> {
    |            -- lifetime `'a` defined here
 8  |           fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
-   |                          ---- lifetime `'lua` defined here
 9  | /             methods.add_async_method("print", |_, data, ()| async move {
 10 | |                 println!("{}", data.0);
 11 | |                 Ok(())
 12 | |             });
-   | |______________^ argument requires that `'a` must outlive `'lua`
-   |
-   = help: consider adding the following bound: `'a: 'lua`
+   | |______________^ requires that `'a` must outlive `'static`

tests/compile/async_userdata_method.rs

@@ -0,0 +1,14 @@
+use mlua::{UserData, UserDataMethods};
+
+struct MyUserData;
+
+impl UserData for MyUserData {
+    fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
+        methods.add_async_method("method", |_, this: &'static Self, ()| async {
+            Ok(())
+        });
+        // ^ lifetime may not live long enough
+    }
+}
+
+fn main() {}

tests/compile/async_userdata_method.stderr

@@ -0,0 +1,17 @@
+warning: unused variable: `this`
+ --> tests/compile/async_userdata_method.rs:7:48
+  |
+7 |         methods.add_async_method("method", |_, this: &'static Self, ()| async {
+  |                                                ^^^^ help: if this is intentional, prefix it with an underscore: `_this`
+  |
+  = note: `#[warn(unused_variables)]` on by default
+
+error: lifetime may not live long enough
+ --> tests/compile/async_userdata_method.rs:7:9
+  |
+6 |       fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
+  |                      ---- lifetime `'lua` defined here
+7 | /         methods.add_async_method("method", |_, this: &'static Self, ()| async {
+8 | |             Ok(())
+9 | |         });
+  | |__________^ argument requires that `'lua` must outlive `'static`

tests/luau.rs

@@ -7,7 +7,9 @@ use std::panic::{catch_unwind, AssertUnwindSafe};
 use std::sync::atomic::{AtomicU64, Ordering};
 use std::sync::Arc;
 
-use mlua::{Compiler, CoverageInfo, Error, Lua, Result, Table, ThreadStatus, Value, VmState};
+use mlua::{
+    Compiler, CoverageInfo, Error, Lua, Result, Table, ThreadStatus, Value, Vector, VmState,
+};
 
 #[test]
 fn test_version() -> Result<()> {
@@ -50,13 +52,18 @@ fn test_require() -> Result<()> {
     .exec()
 }
 
+#[cfg(not(feature = "luau-vector4"))]
 #[test]
 fn test_vectors() -> Result<()> {
     let lua = Lua::new();
 
-    let v: [f32; 3] = lua.load("vector(1, 2, 3) + vector(3, 2, 1)").eval()?;
+    let v: Vector = lua.load("vector(1, 2, 3) + vector(3, 2, 1)").eval()?;
     assert_eq!(v, [4.0, 4.0, 4.0]);
 
+    // Test conversion into Rust array
+    let v: [f64; 3] = lua.load("vector(1, 2, 3)").eval()?;
+    assert!(v == [1.0, 2.0, 3.0]);
+
     // Test vector methods
     lua.load(
         r#"
@@ -83,6 +90,46 @@ fn test_vectors() -> Result<()> {
     Ok(())
 }
 
+#[cfg(feature = "luau-vector4")]
+#[test]
+fn test_vectors() -> Result<()> {
+    let lua = Lua::new();
+
+    let v: Vector = lua.load("vector(1, 2, 3, 4) + vector(4, 3, 2, 1)").eval()?;
+    assert_eq!(v, [5.0, 5.0, 5.0, 5.0]);
+
+    // Test conversion into Rust array
+    let v: [f64; 4] = lua.load("vector(1, 2, 3, 4)").eval()?;
+    assert!(v == [1.0, 2.0, 3.0, 4.0]);
+
+    // Test vector methods
+    lua.load(
+        r#"
+        local v = vector(1, 2, 3, 4)
+        assert(v.x == 1)
+        assert(v.y == 2)
+        assert(v.z == 3)
+        assert(v.w == 4)
+    "#,
+    )
+    .exec()?;
+
+    // Test vector methods (fastcall)
+    lua.load(
+        r#"
+        local v = vector(1, 2, 3, 4)
+        assert(v.x == 1)
+        assert(v.y == 2)
+        assert(v.z == 3)
+        assert(v.w == 4)
+    "#,
+    )
+    .set_compiler(Compiler::new().set_vector_ctor(Some("vector".to_string())))
+    .exec()?;
+
+    Ok(())
+}
+
 #[test]
 fn test_readonly_table() -> Result<()> {
     let lua = Lua::new();
@@ -254,8 +301,8 @@ fn test_coverage() -> Result<()> {
 
     let f = lua
         .load(
-            r#"local v = vector(1, 2, 3)
-        assert(v.x == 1 and v.y == 2 and v.z == 3)
+            r#"local s = "abc"
+        assert(#s == 3)
 
         function abc(i)
             if i < 5 then

tests/serde.rs

@@ -145,7 +145,7 @@ fn test_serialize_failure() -> Result<(), Box<dyn StdError>> {
     Ok(())
 }
 
-#[cfg(feature = "luau")]
+#[cfg(all(feature = "luau", not(feature = "luau-vector4")))]
 #[test]
 fn test_serialize_vector() -> Result<(), Box<dyn StdError>> {
     let lua = Lua::new();
@@ -153,7 +153,7 @@ fn test_serialize_vector() -> Result<(), Box<dyn StdError>> {
     let globals = lua.globals();
     globals.set(
         "vector",
-        lua.create_function(|_, (x, y, z)| Ok(Value::Vector(x, y, z)))?,
+        lua.create_function(|_, (x, y, z)| Ok(mlua::Vector::new(x, y, z)))?,
     )?;
 
     let val = lua.load("{_vector = vector(1, 2, 3)}").eval::<Value>()?;
@@ -168,6 +168,29 @@ fn test_serialize_vector() -> Result<(), Box<dyn StdError>> {
     Ok(())
 }
 
+#[cfg(feature = "luau-vector4")]
+#[test]
+fn test_serialize_vector() -> Result<(), Box<dyn StdError>> {
+    let lua = Lua::new();
+
+    let globals = lua.globals();
+    globals.set(
+        "vector",
+        lua.create_function(|_, (x, y, z, w)| Ok(mlua::Vector::new(x, y, z, w)))?,
+    )?;
+
+    let val = lua.load("{_vector = vector(1, 2, 3, 4)}").eval::<Value>()?;
+    let json = serde_json::json!({
+        "_vector": [1.0, 2.0, 3.0, 4.0],
+    });
+    assert_eq!(serde_json::to_value(&val)?, json);
+
+    let expected_json = lua.from_value::<serde_json::Value>(val)?;
+    assert_eq!(expected_json, json);
+
+    Ok(())
+}
+
 #[test]
 fn test_to_value_struct() -> LuaResult<()> {
     let lua = Lua::new();

tests/table.rs

@@ -57,6 +57,7 @@ fn test_table() -> Result<()> {
             .collect::<Result<Vec<i64>>>()?,
         vec![1, 2, 3, 4, 5]
     );
+    assert_eq!(table1, [1, 2, 3, 4, 5]);
 
     assert_eq!(table2.len()?, 0);
     assert_eq!(
@@ -66,12 +67,10 @@ fn test_table() -> Result<()> {
             .collect::<Result<Vec<(i64, i64)>>>()?,
         vec![]
     );
-    assert_eq!(
-        table2.sequence_values().collect::<Result<Vec<i64>>>()?,
-        vec![]
-    );
+    assert_eq!(table2, [0; 0]);
 
     // sequence_values should only iterate until the first border
+    assert_eq!(table3, [1, 2]);
     assert_eq!(
         table3.sequence_values().collect::<Result<Vec<i64>>>()?,
         vec![1, 2]
@@ -116,17 +115,12 @@ fn test_table_push_pop() -> Result<()> {
     // Test raw access
     let table1 = lua.create_sequence_from(vec![123])?;
     table1.raw_push(321)?;
-    assert_eq!(
-        table1
-            .clone()
-            .raw_sequence_values::<i64>()
-            .collect::<Result<Vec<_>>>()?,
-        vec![123, 321]
-    );
+    assert_eq!(table1, [123, 321]);
     assert_eq!(table1.raw_pop::<i64>()?, 321);
     assert_eq!(table1.raw_pop::<i64>()?, 123);
     assert_eq!(table1.raw_pop::<Value>()?, Value::Nil); // An extra pop should do nothing
     assert_eq!(table1.raw_len(), 0);
+    assert_eq!(table1, [0; 0]);
 
     // Test access through metamethods
     let table2 = lua
@@ -144,6 +138,13 @@ fn test_table_push_pop() -> Result<()> {
         .eval::<Table>()?;
     table2.push(345)?;
     assert_eq!(table2.len()?, 2);
+    assert_eq!(
+        table2
+            .clone()
+            .raw_sequence_values::<i64>()
+            .collect::<Result<Vec<_>>>()?,
+        vec![]
+    );
     assert_eq!(table2.pop::<i64>()?, 345);
     assert_eq!(table2.pop::<i64>()?, 234);
     assert_eq!(table2.pop::<Value>()?, Value::Nil);
@@ -205,29 +206,9 @@ fn test_table_sequence_from() -> Result<()> {
 
     let get_table = lua.create_function(|_, t: Table| Ok(t))?;
 
-    assert_eq!(
-        get_table
-            .call::<_, Table>(vec![1, 2, 3])?
-            .sequence_values()
-            .collect::<Result<Vec<i64>>>()?,
-        vec![1, 2, 3]
-    );
-
-    assert_eq!(
-        get_table
-            .call::<_, Table>([1, 2, 3].as_ref())?
-            .sequence_values()
-            .collect::<Result<Vec<i64>>>()?,
-        vec![1, 2, 3]
-    );
-
-    assert_eq!(
-        get_table
-            .call::<_, Table>([1, 2, 3])?
-            .sequence_values()
-            .collect::<Result<Vec<i64>>>()?,
-        vec![1, 2, 3]
-    );
+    assert_eq!(get_table.call::<_, Table>(vec![1, 2, 3])?, [1, 2, 3]);
+    assert_eq!(get_table.call::<_, Table>([4, 5, 6])?, [4, 5, 6]);
+    assert_eq!(get_table.call::<_, Table>([7, 8, 9].as_slice())?, [7, 8, 9]);
 
     Ok(())
 }

tests/userdata.rs

@@ -625,10 +625,33 @@ fn test_userdata_wrapped() -> Result<()> {
     let lua = Lua::new();
     let globals = lua.globals();
 
+    // Rc<T>
     #[cfg(not(feature = "send"))]
     {
-        let ud1 = Rc::new(RefCell::new(MyUserData(1)));
-        globals.set("rc_refcell_ud", ud1.clone())?;
+        let ud = Rc::new(MyUserData(1));
+        globals.set("rc_ud", ud.clone())?;
+        lua.load(
+            r#"
+            assert(rc_ud.static == "constant")
+            local ok, err = pcall(function() rc_ud.data = 2 end)
+            assert(
+                tostring(err):sub(1, 32) == "error mutably borrowing userdata",
+                "expected error mutably borrowing userdata, got " .. tostring(err)
+            )
+            assert(rc_ud.data == 1)
+        "#,
+        )
+        .exec()?;
+        globals.set("rc_ud", Nil)?;
+        lua.gc_collect()?;
+        assert_eq!(Rc::strong_count(&ud), 1);
+    }
+
+    // Rc<RefCell<T>>
+    #[cfg(not(feature = "send"))]
+    {
+        let ud = Rc::new(RefCell::new(MyUserData(1)));
+        globals.set("rc_refcell_ud", ud.clone())?;
         lua.load(
             r#"
             assert(rc_refcell_ud.static == "constant")
@@ -637,12 +660,32 @@ fn test_userdata_wrapped() -> Result<()> {
         "#,
         )
         .exec()?;
-        assert_eq!(ud1.borrow().0, 2);
+        assert_eq!(ud.borrow().0, 2);
         globals.set("rc_refcell_ud", Nil)?;
         lua.gc_collect()?;
-        assert_eq!(Rc::strong_count(&ud1), 1);
+        assert_eq!(Rc::strong_count(&ud), 1);
     }
 
+    // Arc<T>
+    let ud1 = Arc::new(MyUserData(2));
+    globals.set("arc_ud", ud1.clone())?;
+    lua.load(
+        r#"
+        assert(arc_ud.static == "constant")
+        local ok, err = pcall(function() arc_ud.data = 3 end)
+        assert(
+            tostring(err):sub(1, 32) == "error mutably borrowing userdata",
+            "expected error mutably borrowing userdata, got " .. tostring(err)
+        )
+        assert(arc_ud.data == 2)
+    "#,
+    )
+    .exec()?;
+    globals.set("arc_ud", Nil)?;
+    lua.gc_collect()?;
+    assert_eq!(Arc::strong_count(&ud1), 1);
+
+    // Arc<Mutex<T>>
     let ud2 = Arc::new(Mutex::new(MyUserData(2)));
     globals.set("arc_mutex_ud", ud2.clone())?;
     lua.load(
@@ -657,7 +700,11 @@ fn test_userdata_wrapped() -> Result<()> {
     assert_eq!(ud2.lock().unwrap().0, 3);
     #[cfg(feature = "parking_lot")]
     assert_eq!(ud2.lock().0, 3);
+    globals.set("arc_mutex_ud", Nil)?;
+    lua.gc_collect()?;
+    assert_eq!(Arc::strong_count(&ud2), 1);
 
+    // Arc<RwLock<T>>
     let ud3 = Arc::new(RwLock::new(MyUserData(3)));
     globals.set("arc_rwlock_ud", ud3.clone())?;
     lua.load(
@@ -672,12 +719,8 @@ fn test_userdata_wrapped() -> Result<()> {
     assert_eq!(ud3.read().unwrap().0, 4);
     #[cfg(feature = "parking_lot")]
     assert_eq!(ud3.read().0, 4);
-
-    // Test drop
-    globals.set("arc_mutex_ud", Nil)?;
     globals.set("arc_rwlock_ud", Nil)?;
     lua.gc_collect()?;
-    assert_eq!(Arc::strong_count(&ud2), 1);
     assert_eq!(Arc::strong_count(&ud3), 1);
 
     Ok(())

tests/value.rs

@@ -101,11 +101,16 @@ fn test_value_to_string() -> Result<()> {
     );
     assert_eq!(Value::Integer(1).to_string()?, "1");
     assert_eq!(Value::Number(34.59).to_string()?, "34.59");
-    #[cfg(feature = "luau")]
+    #[cfg(all(feature = "luau", not(feature = "luau-vector4")))]
     assert_eq!(
-        Value::Vector(10.0, 11.1, 12.2).to_string()?,
+        Value::Vector(mlua::Vector::new(10.0, 11.1, 12.2)).to_string()?,
         "vector(10, 11.1, 12.2)"
     );
+    #[cfg(feature = "luau-vector4")]
+    assert_eq!(
+        Value::Vector(mlua::Vector::new(10.0, 11.1, 12.2, 13.3)).to_string()?,
+        "vector(10, 11.1, 12.2, 13.3)"
+    );
     assert_eq!(
         Value::String(lua.create_string("hello")?).to_string()?,
         "hello"