diff --git a/sol/object.hpp b/sol/object.hpp
index 2a6e628d..b44571ac 100644
--- a/sol/object.hpp
+++ b/sol/object.hpp
@@ -1,141 +1,150 @@
-// The MIT License (MIT) 
-
-// Copyright (c) 2013-2016 Rapptz, ThePhD and contributors
-
-// Permission is hereby granted, free of charge, to any person obtaining a copy of
-// this software and associated documentation files (the "Software"), to deal in
-// the Software without restriction, including without limitation the rights to
-// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
-// the Software, and to permit persons to whom the Software is furnished to do so,
-// subject to the following conditions:
-
-// The above copyright notice and this permission notice shall be included in all
-// copies or substantial portions of the Software.
-
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
-// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
-// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
-// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
-// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-
-#ifndef SOL_OBJECT_HPP
-#define SOL_OBJECT_HPP
-
-#include "optional.hpp"
-#include "reference.hpp"
-#include "stack.hpp"
-#include "userdata.hpp"
-#include "variadic_args.hpp"
-
-namespace sol {
-
-	template <typename R = reference, bool should_pop = !std::is_base_of<stack_reference, R>::value, typename T>
-	R make_reference(lua_State* L, T&& value) {
-		int backpedal = stack::push(L, std::forward<T>(value));
-		R r = stack::get<R>(L, -backpedal);
-		if (should_pop) {
-			lua_pop(L, backpedal);
-		}
-		return r;
-	}
-
-	template <typename T, typename R = reference, bool should_pop = !std::is_base_of<stack_reference, R>::value, typename... Args>
-	R make_reference(lua_State* L, Args&&... args) {
-		int backpedal = stack::push<T>(L, std::forward<Args>(args)...);
-		R r = stack::get<R>(L, -backpedal);
-		if (should_pop) {
-			lua_pop(L, backpedal);
-		}
-		return r;
-	}
-
-	template <typename base_t>
-	class basic_object : public base_t {
-	private:
-		template<typename T>
-		decltype(auto) as_stack(std::true_type) const {
-			return stack::get<T>(base_t::lua_state(), base_t::stack_index());
-		}
-
-		template<typename T>
-		decltype(auto) as_stack(std::false_type) const {
-			base_t::push();
-			return stack::pop<T>(base_t::lua_state());
-		}
-
-		template<typename T>
-		bool is_stack(std::true_type) const {
-			return stack::check<T>(base_t::lua_state(), base_t::stack_index(), no_panic);
-		}
-
-		template<typename T>
-		bool is_stack(std::false_type) const {
-			auto pp = stack::push_pop(*this);
-			return stack::check<T>(base_t::lua_state(), -1, no_panic);
-		}
-		template <bool invert_and_pop = false>
-		basic_object(std::integral_constant<bool, invert_and_pop>, lua_State* L, int index = -1) noexcept : base_t(L, index) {
+// The MIT License (MIT) 
+
+// Copyright (c) 2013-2016 Rapptz, ThePhD and contributors
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+// the Software, and to permit persons to whom the Software is furnished to do so,
+// subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+#ifndef SOL_OBJECT_HPP
+#define SOL_OBJECT_HPP
+
+#include "optional.hpp"
+#include "reference.hpp"
+#include "stack.hpp"
+#include "userdata.hpp"
+#include "variadic_args.hpp"
+
+namespace sol {
+
+	template <typename R = reference, bool should_pop = !std::is_base_of<stack_reference, R>::value, typename T>
+	R make_reference(lua_State* L, T&& value) {
+		int backpedal = stack::push(L, std::forward<T>(value));
+		R r = stack::get<R>(L, -backpedal);
+		if (should_pop) {
+			lua_pop(L, backpedal);
+		}
+		return r;
+	}
+
+	template <typename T, typename R = reference, bool should_pop = !std::is_base_of<stack_reference, R>::value, typename... Args>
+	R make_reference(lua_State* L, Args&&... args) {
+		int backpedal = stack::push<T>(L, std::forward<Args>(args)...);
+		R r = stack::get<R>(L, -backpedal);
+		if (should_pop) {
+			lua_pop(L, backpedal);
+		}
+		return r;
+	}
+
+	template <typename base_t>
+	class basic_object : public base_t {
+	private:
+		template<typename T>
+		decltype(auto) as_stack(std::true_type) const {
+			return stack::get<T>(base_t::lua_state(), base_t::stack_index());
+		}
+
+		template<typename T>
+		decltype(auto) as_stack(std::false_type) const {
+			base_t::push();
+			return stack::pop<T>(base_t::lua_state());
+		}
+
+		template<typename T>
+		bool is_stack(std::true_type) const {
+			return stack::check<T>(base_t::lua_state(), base_t::stack_index(), no_panic);
+		}
+
+		template<typename T>
+		bool is_stack(std::false_type) const {
+			auto pp = stack::push_pop(*this);
+			return stack::check<T>(base_t::lua_state(), -1, no_panic);
+		}
+
+		template <bool invert_and_pop = false>
+		basic_object(std::integral_constant<bool, invert_and_pop>, lua_State* L, int index = -1) noexcept : base_t(L, index) {
 			if (invert_and_pop) {
 				lua_pop(L, -index);
 			}
-		}
-
-	public:
-		basic_object() noexcept = default;
-		template <typename T, meta::enable<meta::neg<std::is_same<meta::unqualified_t<T>, basic_object>>, std::is_base_of<base_t, meta::unqualified_t<T>>> = meta::enabler>
-		basic_object(T&& r) : base_t(std::forward<T>(r)) {}
-		basic_object(nil_t r) : base_t(r) {}
-		basic_object(const basic_object&) = default;
-		basic_object(basic_object&&) = default;
-		basic_object& operator=(const basic_object&) = default;
-		basic_object& operator=(basic_object&&) = default;
-		basic_object(const stack_reference& r) noexcept : basic_object(r.lua_state(), r.stack_index()) {}
-		basic_object(stack_reference&& r) noexcept : basic_object(r.lua_state(), r.stack_index()) {}
-		basic_object(lua_State* L, int index = -1) noexcept : base_t(L, index) {}
-		template <typename T, typename... Args>
-		basic_object(lua_State* L, in_place_type_t<T>, Args&&... args) noexcept : basic_object(std::integral_constant<bool, !std::is_base_of<stack_reference, base_t>::value>(), L, -stack::push<T>(L, std::forward<Args>(args)...)) {}
-		template <typename T, typename... Args>
-		basic_object(lua_State* L, in_place_t, T&& arg, Args&&... args) noexcept : basic_object(L, in_place<T>, std::forward<T>(arg), std::forward<Args>(args)...) {}
-
-		template<typename T>
-		decltype(auto) as() const {
-			return as_stack<T>(std::is_same<base_t, stack_reference>());
-		}
-
-		template<typename T>
-		bool is() const {
-			if (!base_t::valid())
-				return false;
-			return is_stack<T>(std::is_same<base_t, stack_reference>());
-		}
-	};
-
-	template <typename T>
-	object make_object(lua_State* L, T&& value) {
-		return make_reference<object, true>(L, std::forward<T>(value));
-	}
-
-	template <typename T, typename... Args>
-	object make_object(lua_State* L, Args&&... args) {
-		return make_reference<T, object, true>(L, std::forward<Args>(args)...);
-	}
-
-	inline bool operator==(const object& lhs, const nil_t&) {
-		return !lhs.valid();
-	}
-
-	inline bool operator==(const nil_t&, const object& rhs) {
-		return !rhs.valid();
-	}
-
-	inline bool operator!=(const object& lhs, const nil_t&) {
-		return lhs.valid();
-	}
-
-	inline bool operator!=(const nil_t&, const object& rhs) {
-		return rhs.valid();
-	}
-} // sol
-
-#endif // SOL_OBJECT_HPP
+		}
+
+	public:
+		basic_object() noexcept = default;
+		template <typename T, meta::enable<meta::neg<std::is_same<meta::unqualified_t<T>, basic_object>>, std::is_base_of<base_t, meta::unqualified_t<T>>> = meta::enabler>
+		basic_object(T&& r) : base_t(std::forward<T>(r)) {}
+		basic_object(nil_t r) : base_t(r) {}
+		basic_object(const basic_object&) = default;
+		basic_object(basic_object&&) = default;
+		basic_object& operator=(const basic_object&) = default;
+		basic_object& operator=(basic_object&&) = default;
+		basic_object& operator=(const base_t& b) {
+			base_t::operator=(b);
+			return *this;
+		}
+		basic_object& operator=(base_t&& b) {
+			base_t::operator=(std::move(b));
+			return *this;
+		}
+		basic_object(const stack_reference& r) noexcept : basic_object(r.lua_state(), r.stack_index()) {}
+		basic_object(stack_reference&& r) noexcept : basic_object(r.lua_state(), r.stack_index()) {}
+		basic_object(lua_State* L, int index = -1) noexcept : base_t(L, index) {}
+		template <typename T, typename... Args>
+		basic_object(lua_State* L, in_place_type_t<T>, Args&&... args) noexcept : basic_object(std::integral_constant<bool, !std::is_base_of<stack_reference, base_t>::value>(), L, -stack::push<T>(L, std::forward<Args>(args)...)) {}
+		template <typename T, typename... Args>
+		basic_object(lua_State* L, in_place_t, T&& arg, Args&&... args) noexcept : basic_object(L, in_place<T>, std::forward<T>(arg), std::forward<Args>(args)...) {}
+
+		template<typename T>
+		decltype(auto) as() const {
+			return as_stack<T>(std::is_same<base_t, stack_reference>());
+		}
+
+		template<typename T>
+		bool is() const {
+			if (!base_t::valid())
+				return false;
+			return is_stack<T>(std::is_same<base_t, stack_reference>());
+		}
+	};
+
+	template <typename T>
+	object make_object(lua_State* L, T&& value) {
+		return make_reference<object, true>(L, std::forward<T>(value));
+	}
+
+	template <typename T, typename... Args>
+	object make_object(lua_State* L, Args&&... args) {
+		return make_reference<T, object, true>(L, std::forward<Args>(args)...);
+	}
+
+	inline bool operator==(const object& lhs, const nil_t&) {
+		return !lhs.valid();
+	}
+
+	inline bool operator==(const nil_t&, const object& rhs) {
+		return !rhs.valid();
+	}
+
+	inline bool operator!=(const object& lhs, const nil_t&) {
+		return lhs.valid();
+	}
+
+	inline bool operator!=(const nil_t&, const object& rhs) {
+		return rhs.valid();
+	}
+} // sol
+
+#endif // SOL_OBJECT_HPP
diff --git a/sol/stack_get.hpp b/sol/stack_get.hpp
index 38769ac9..52c52efa 100644
--- a/sol/stack_get.hpp
+++ b/sol/stack_get.hpp
@@ -334,15 +334,15 @@ namespace sol {
 		struct getter<wchar_t> {
 			static wchar_t get(lua_State* L, int index, record& tracking) {
 				auto str = getter<std::wstring>{}.get(L, index, tracking);
-				return str.size() > 0 ? str[0] : '\0';
+				return str.size() > 0 ? str[0] : wchar_t(0);
 			}
 		};
 
 		template<>
 		struct getter<char16_t> {
-			static char get(lua_State* L, int index, record& tracking) {
+			static char16_t get(lua_State* L, int index, record& tracking) {
 				auto str = getter<std::u16string>{}.get(L, index, tracking);
-				return str.size() > 0 ? str[0] : '\0';
+				return str.size() > 0 ? str[0] : char16_t(0);
 			}
 		};
 
@@ -350,7 +350,7 @@ namespace sol {
 		struct getter<char32_t> {
 			static char32_t get(lua_State* L, int index, record& tracking) {
 				auto str = getter<std::u32string>{}.get(L, index, tracking);
-				return str.size() > 0 ? str[0] : '\0';
+				return str.size() > 0 ? str[0] : char32_t(0);
 			}
 		};
 #endif // codecvt header support
diff --git a/sol/tie.hpp b/sol/tie.hpp
index 9f131324..fc3ec155 100644
--- a/sol/tie.hpp
+++ b/sol/tie.hpp
@@ -85,7 +85,7 @@ namespace sol {
 	};
 
 	template <typename... Tn>
-	struct tie_size<::sol::tie_t<Tn...>> : ::std::tuple_size<::std::tuple<Tn...>> { };
+	struct tie_size< tie_t<Tn...> > : std::tuple_size< std::tuple<Tn...> > { };
 
 	namespace adl_barrier_detail {
 		template <typename... Tn>
diff --git a/sol/types.hpp b/sol/types.hpp
index c487cef2..1c65fb13 100644
--- a/sol/types.hpp
+++ b/sol/types.hpp
@@ -138,8 +138,8 @@ namespace sol {
 		typedef std::shared_ptr<T> actual_type;
 		static const bool value = true;
 
-		static bool is_null(const actual_type& value) {
-			return value == nullptr;
+		static bool is_null(const actual_type& p) {
+			return p == nullptr;
 		}
 
 		static type* get(const actual_type& p) {
@@ -153,8 +153,8 @@ namespace sol {
 		typedef std::unique_ptr<T, D> actual_type;
 		static const bool value = true;
 
-		static bool is_null(const actual_type& value) {
-			return value == nullptr;
+		static bool is_null(const actual_type& p) {
+			return p == nullptr;
 		}
 
 		static type* get(const actual_type& p) {
diff --git a/test_usertypes.cpp b/test_usertypes.cpp
index 39ce8b27..8d5d6c01 100644
--- a/test_usertypes.cpp
+++ b/test_usertypes.cpp
@@ -349,7 +349,6 @@ TEST_CASE("usertype/usertype-utility-derived", "usertype classes must play nice
 	lua.set_usertype(derivedusertype);
 
 	lua.script("derived = Derived.new(7)");
-	Derived& derived = lua["derived"];
 	lua.script("dgn = derived:get_num()\n"
 		"print(dgn)");
 	lua.script("dgn10 = derived:get_num_10()\n"
@@ -608,6 +607,8 @@ TEST_CASE("usertype/destructor-tests", "Show that proper copies / destruction ha
 		REQUIRE(created == 4);
 		REQUIRE(destroyed == 0);
 		REQUIRE(std::addressof(x1) == std::addressof(x1ref));
+		REQUIRE(std::addressof(x1copyref) != std::addressof(x1));
+		REQUIRE(std::addressof(x2copyref) != std::addressof(x2));
 	}
 	REQUIRE(created == 4);
 	REQUIRE(destroyed == 4);