Alex Orlenko

Thanks for reporting. A quick investigation showed the problem with regex crate. I raised the issue [#389](https://github.com/rust-lang/regex/issues/389)

There are few options how to solve this: 1) Store Lua values in userdata using [`set_nth_user_value`](https://docs.rs/mlua/latest/mlua/struct.AnyUserData.html#method.set_nth_user_value) api (recommended) 2) Store Lua values in Registry using [`crate_registry_value`](https://docs.rs/mlua/latest/mlua/struct.Lua.html#method.create_registry_value) api and then store...

Try [`Scope::create_nonstatic_userdata`](https://docs.rs/mlua/latest/mlua/struct.Scope.html#method.create_nonstatic_userdata). It's slower alternative that does not require `T: 'static`.

Unfortunately non-`'static` types don't implement [`Any`](https://doc.rust-lang.org/stable/std/any/trait.Any.html) trait which is the main blocker.

There are no benefics in LuaJIT for this specific test case. LuaJIT does not perform any jit optimizations when working with Lua C API, and instead requires C ffi to...

I have not investigated yet how to measure memory while benchmarking, but will take a look

PR is welcome :)

Unfortunately `send` feature flag is not compatible with `module` mode. In module mode mlua does not control access to the Lua VM and cannot guarantee that lock is always acquired...

I'm working on adding Pluto support to next mlua and will check. Are you using a custom Pluto build with some functionality disabled?

Can you try [any userdata api](https://docs.rs/mlua/0.10.0-rc.1/mlua/struct.Lua.html#method.register_userdata_type) instead? The main motivation to support `Rc`/`Arc` types was inability to implement `UserData` trait for `Rc` because of orphan rules, but since then it...