diff --git a/Utilities/recursive_wrapper.hpp b/Utilities/recursive_wrapper.hpp
new file mode 100644
index 0000000000..82317e1695
--- /dev/null
+++ b/Utilities/recursive_wrapper.hpp
@@ -0,0 +1,124 @@
+#ifndef MAPBOX_UTIL_RECURSIVE_WRAPPER_HPP
+#define MAPBOX_UTIL_RECURSIVE_WRAPPER_HPP
+
+// Based on variant/recursive_wrapper.hpp from boost.
+//
+// Original license:
+//
+// Copyright (c) 2002-2003
+// Eric Friedman, Itay Maman
+//
+// Distributed under the Boost Software License, Version 1.0. (See
+// accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+#include <cassert>
+#include <utility>
+
+//namespace mapbox {
+//namespace util {
+namespace std {
+
+template <typename T>
+class recursive_wrapper
+{
+
+    T* p_;
+
+    void assign(T const& rhs)
+    {
+        this->get() = rhs;
+    }
+
+public:
+    using type = T;
+
+    /**
+     * Default constructor default initializes the internally stored value.
+     * For POD types this means nothing is done and the storage is
+     * uninitialized.
+     *
+     * @throws std::bad_alloc if there is insufficient memory for an object
+     *         of type T.
+     * @throws any exception thrown by the default constructur of T.
+     */
+    recursive_wrapper()
+        : p_(new T){}
+
+    ~recursive_wrapper() noexcept { delete p_; }
+
+    recursive_wrapper(recursive_wrapper const& operand)
+        : p_(new T(operand.get())) {}
+
+    recursive_wrapper(T const& operand)
+        : p_(new T(operand)) {}
+
+    recursive_wrapper(recursive_wrapper&& operand)
+        : p_(new T(std::move(operand.get()))) {}
+
+    recursive_wrapper(T&& operand)
+        : p_(new T(std::move(operand))) {}
+
+    inline recursive_wrapper& operator=(recursive_wrapper const& rhs)
+    {
+        assign(rhs.get());
+        return *this;
+    }
+
+    inline recursive_wrapper& operator=(T const& rhs)
+    {
+        assign(rhs);
+        return *this;
+    }
+
+    inline void swap(recursive_wrapper& operand) noexcept
+    {
+        T* temp = operand.p_;
+        operand.p_ = p_;
+        p_ = temp;
+    }
+
+    recursive_wrapper& operator=(recursive_wrapper&& rhs) noexcept
+    {
+        swap(rhs);
+        return *this;
+    }
+
+    recursive_wrapper& operator=(T&& rhs)
+    {
+        get() = std::move(rhs);
+        return *this;
+    }
+
+    T& get()
+    {
+        assert(p_);
+        return *get_pointer();
+    }
+
+    T const& get() const
+    {
+        assert(p_);
+        return *get_pointer();
+    }
+
+    T* get_pointer() { return p_; }
+
+    const T* get_pointer() const { return p_; }
+
+    operator T const&() const { return this->get(); }
+
+    operator T&() { return this->get(); }
+
+}; // class recursive_wrapper
+
+template <typename T>
+inline void swap(recursive_wrapper<T>& lhs, recursive_wrapper<T>& rhs) noexcept
+{
+    lhs.swap(rhs);
+}
+}
+//} // namespace util
+//} // namespace mapbox
+
+#endif // MAPBOX_UTIL_RECURSIVE_WRAPPER_HPP
diff --git a/Utilities/variant.hpp b/Utilities/variant.hpp
new file mode 100644
index 0000000000..b712445bb7
--- /dev/null
+++ b/Utilities/variant.hpp
@@ -0,0 +1,973 @@
+#ifndef MAPBOX_UTIL_VARIANT_HPP
+#define MAPBOX_UTIL_VARIANT_HPP
+
+#include <cassert>
+#include <cstddef>   // size_t
+#include <new>       // operator new
+#include <stdexcept> // runtime_error
+#include <string>
+#include <tuple>
+#include <type_traits>
+#include <typeinfo>
+#include <utility>
+
+#include "recursive_wrapper.hpp"
+
+// clang-format off
+// [[deprecated]] is only available in C++14, use this for the time being
+#if __cplusplus <= 201103L
+# ifdef __GNUC__
+#  define MAPBOX_VARIANT_DEPRECATED __attribute__((deprecated))
+# elif defined(_MSC_VER)
+#  define MAPBOX_VARIANT_DEPRECATED __declspec(deprecated)
+# else
+#  define MAPBOX_VARIANT_DEPRECATED
+# endif
+#else
+#  define MAPBOX_VARIANT_DEPRECATED [[deprecated]]
+#endif
+
+
+#ifdef _MSC_VER
+// https://msdn.microsoft.com/en-us/library/bw1hbe6y.aspx
+# ifdef NDEBUG
+#  define VARIANT_INLINE __forceinline
+# else
+#  define VARIANT_INLINE //__declspec(noinline)
+# endif
+#else
+# ifdef NDEBUG
+#  define VARIANT_INLINE //inline __attribute__((always_inline))
+# else
+#  define VARIANT_INLINE __attribute__((noinline))
+# endif
+#endif
+// clang-format on
+
+// Exceptions
+#if defined( __EXCEPTIONS) || defined( _MSC_VER)
+#define HAS_EXCEPTIONS
+#endif
+
+#define VARIANT_MAJOR_VERSION 1
+#define VARIANT_MINOR_VERSION 1
+#define VARIANT_PATCH_VERSION 0
+
+#define VARIANT_VERSION (VARIANT_MAJOR_VERSION * 100000) + (VARIANT_MINOR_VERSION * 100) + (VARIANT_PATCH_VERSION)
+
+//namespace mapbox {
+//	namespace util {
+namespace std {
+
+		// XXX This should derive from std::logic_error instead of std::runtime_error.
+		//     See https://github.com/mapbox/variant/issues/48 for details.
+		class bad_variant_access : public std::runtime_error
+		{
+
+		public:
+			explicit bad_variant_access(const std::string& what_arg)
+				: runtime_error(what_arg) {}
+
+			explicit bad_variant_access(const char* what_arg)
+				: runtime_error(what_arg) {}
+
+		}; // class bad_variant_access
+
+		template <typename R = void>
+		struct MAPBOX_VARIANT_DEPRECATED static_visitor
+		{
+			using result_type = R;
+
+		protected:
+			static_visitor() {}
+			~static_visitor() {}
+		};
+
+		namespace detail {
+
+			static constexpr std::size_t invalid_value = std::size_t(-1);
+
+			template <typename T, typename... Types>
+			struct direct_type;
+
+			template <typename T, typename First, typename... Types>
+			struct direct_type<T, First, Types...>
+			{
+				static constexpr std::size_t index = std::is_same<T, First>::value
+					? sizeof...(Types)
+					: direct_type<T, Types...>::index;
+			};
+
+			template <typename T>
+			struct direct_type<T>
+			{
+				static constexpr std::size_t index = invalid_value;
+			};
+
+#if __cpp_lib_logical_traits >= 201510L
+
+			using std::disjunction;
+
+#else
+
+			template <typename...>
+			struct disjunction : std::false_type {};
+
+			template <typename B1>
+			struct disjunction<B1> : B1 {};
+
+			template <typename B1, typename B2>
+			struct disjunction<B1, B2> : std::conditional<B1::value, B1, B2>::type {};
+
+			template <typename B1, typename... Bs>
+			struct disjunction<B1, Bs...> : std::conditional<B1::value, B1, disjunction<Bs...>>::type {};
+
+#endif
+
+			template <typename T, typename... Types>
+			struct convertible_type;
+
+			template <typename T, typename First, typename... Types>
+			struct convertible_type<T, First, Types...>
+			{
+				static constexpr std::size_t index = std::is_convertible<T, First>::value
+					? disjunction<std::is_convertible<T, Types>...>::value ? invalid_value : sizeof...(Types)
+					: convertible_type<T, Types...>::index;
+			};
+
+			template <typename T>
+			struct convertible_type<T>
+			{
+				static constexpr std::size_t index = invalid_value;
+			};
+
+			template <typename T, typename... Types>
+			struct value_traits
+			{
+				using value_type = typename std::remove_const<typename std::remove_reference<T>::type>::type;
+				static constexpr std::size_t direct_index = direct_type<value_type, Types...>::index;
+				static constexpr bool is_direct = direct_index != invalid_value;
+				static constexpr std::size_t index = is_direct ? direct_index : convertible_type<value_type, Types...>::index;
+				static constexpr bool is_valid = index != invalid_value;
+				static constexpr std::size_t tindex = is_valid ? sizeof...(Types)-index : 0;
+				using target_type = typename std::tuple_element<tindex, std::tuple<void, Types...>>::type;
+			};
+
+			template <typename T, typename R = void>
+			struct enable_if_type
+			{
+				using type = R;
+			};
+
+			template <typename F, typename V, typename Enable = void>
+			struct result_of_unary_visit
+			{
+				using type = typename std::result_of<F(V&)>::type;
+			};
+
+			template <typename F, typename V>
+			struct result_of_unary_visit<F, V, typename enable_if_type<typename F::result_type>::type>
+			{
+				using type = typename F::result_type;
+			};
+
+			template <typename F, typename V, typename Enable = void>
+			struct result_of_binary_visit
+			{
+				using type = typename std::result_of<F(V&, V&)>::type;
+			};
+
+			template <typename F, typename V>
+			struct result_of_binary_visit<F, V, typename enable_if_type<typename F::result_type>::type>
+			{
+				using type = typename F::result_type;
+			};
+
+			template <std::size_t arg1, std::size_t... others>
+			struct static_max;
+
+			template <std::size_t arg>
+			struct static_max<arg>
+			{
+				static const std::size_t value = arg;
+			};
+
+			template <std::size_t arg1, std::size_t arg2, std::size_t... others>
+			struct static_max<arg1, arg2, others...>
+			{
+				static const std::size_t value = arg1 >= arg2 ? static_max<arg1, others...>::value : static_max<arg2, others...>::value;
+			};
+
+			template <typename... Types>
+			struct variant_helper;
+
+			template <typename T, typename... Types>
+			struct variant_helper<T, Types...>
+			{
+				VARIANT_INLINE static void destroy(const std::size_t type_index, void* data)
+				{
+					if (type_index == sizeof...(Types))
+					{
+						reinterpret_cast<T*>(data)->~T();
+					}
+					else
+					{
+						variant_helper<Types...>::destroy(type_index, data);
+					}
+				}
+
+				VARIANT_INLINE static void move(const std::size_t old_type_index, void* old_value, void* new_value)
+				{
+					if (old_type_index == sizeof...(Types))
+					{
+						new (new_value) T(std::move(*reinterpret_cast<T*>(old_value)));
+					}
+					else
+					{
+						variant_helper<Types...>::move(old_type_index, old_value, new_value);
+					}
+				}
+
+				VARIANT_INLINE static void copy(const std::size_t old_type_index, const void* old_value, void* new_value)
+				{
+					if (old_type_index == sizeof...(Types))
+					{
+						new (new_value) T(*reinterpret_cast<const T*>(old_value));
+					}
+					else
+					{
+						variant_helper<Types...>::copy(old_type_index, old_value, new_value);
+					}
+				}
+			};
+
+			template <>
+			struct variant_helper<>
+			{
+				VARIANT_INLINE static void destroy(const std::size_t, void*) {}
+				VARIANT_INLINE static void move(const std::size_t, void*, void*) {}
+				VARIANT_INLINE static void copy(const std::size_t, const void*, void*) {}
+			};
+
+			template <typename T>
+			struct unwrapper
+			{
+				static T const& apply_const(T const& obj) { return obj; }
+				static T& apply(T& obj) { return obj; }
+			};
+
+			template <typename T>
+			struct unwrapper<recursive_wrapper<T>>
+			{
+				static auto apply_const(recursive_wrapper<T> const& obj)
+					-> typename recursive_wrapper<T>::type const&
+				{
+					return obj.get();
+				}
+				static auto apply(recursive_wrapper<T>& obj)
+					-> typename recursive_wrapper<T>::type&
+				{
+					return obj.get();
+				}
+			};
+
+			template <typename T>
+			struct unwrapper<std::reference_wrapper<T>>
+			{
+				static auto apply_const(std::reference_wrapper<T> const& obj)
+					-> typename std::reference_wrapper<T>::type const&
+				{
+					return obj.get();
+				}
+				static auto apply(std::reference_wrapper<T>& obj)
+					-> typename std::reference_wrapper<T>::type&
+				{
+					return obj.get();
+				}
+			};
+
+			template <typename F, typename V, typename R, typename... Types>
+			struct dispatcher;
+
+			template <typename F, typename V, typename R, typename T, typename... Types>
+			struct dispatcher<F, V, R, T, Types...>
+			{
+				VARIANT_INLINE static R apply_const(V const& v, F&& f)
+				{
+					if (v.template is<T>())
+					{
+						return f(unwrapper<T>::apply_const(v.template get_unchecked<T>()));
+					}
+					else
+					{
+						return dispatcher<F, V, R, Types...>::apply_const(v, std::forward<F>(f));
+					}
+				}
+
+				VARIANT_INLINE static R apply(V& v, F&& f)
+				{
+					if (v.template is<T>())
+					{
+						return f(unwrapper<T>::apply(v.template get_unchecked<T>()));
+					}
+					else
+					{
+						return dispatcher<F, V, R, Types...>::apply(v, std::forward<F>(f));
+					}
+				}
+			};
+
+			template <typename F, typename V, typename R, typename T>
+			struct dispatcher<F, V, R, T>
+			{
+				VARIANT_INLINE static R apply_const(V const& v, F&& f)
+				{
+					return f(unwrapper<T>::apply_const(v.template get_unchecked<T>()));
+				}
+
+				VARIANT_INLINE static R apply(V& v, F&& f)
+				{
+					return f(unwrapper<T>::apply(v.template get_unchecked<T>()));
+				}
+			};
+
+			template <typename F, typename V, typename R, typename T, typename... Types>
+			struct binary_dispatcher_rhs;
+
+			template <typename F, typename V, typename R, typename T0, typename T1, typename... Types>
+			struct binary_dispatcher_rhs<F, V, R, T0, T1, Types...>
+			{
+				VARIANT_INLINE static R apply_const(V const& lhs, V const& rhs, F&& f)
+				{
+					if (rhs.template is<T1>()) // call binary functor
+					{
+						return f(unwrapper<T0>::apply_const(lhs.template get_unchecked<T0>()),
+							unwrapper<T1>::apply_const(rhs.template get_unchecked<T1>()));
+					}
+					else
+					{
+						return binary_dispatcher_rhs<F, V, R, T0, Types...>::apply_const(lhs, rhs, std::forward<F>(f));
+					}
+				}
+
+				VARIANT_INLINE static R apply(V& lhs, V& rhs, F&& f)
+				{
+					if (rhs.template is<T1>()) // call binary functor
+					{
+						return f(unwrapper<T0>::apply(lhs.template get_unchecked<T0>()),
+							unwrapper<T1>::apply(rhs.template get_unchecked<T1>()));
+					}
+					else
+					{
+						return binary_dispatcher_rhs<F, V, R, T0, Types...>::apply(lhs, rhs, std::forward<F>(f));
+					}
+				}
+			};
+
+			template <typename F, typename V, typename R, typename T0, typename T1>
+			struct binary_dispatcher_rhs<F, V, R, T0, T1>
+			{
+				VARIANT_INLINE static R apply_const(V const& lhs, V const& rhs, F&& f)
+				{
+					return f(unwrapper<T0>::apply_const(lhs.template get_unchecked<T0>()),
+						unwrapper<T1>::apply_const(rhs.template get_unchecked<T1>()));
+				}
+
+				VARIANT_INLINE static R apply(V& lhs, V& rhs, F&& f)
+				{
+					return f(unwrapper<T0>::apply(lhs.template get_unchecked<T0>()),
+						unwrapper<T1>::apply(rhs.template get_unchecked<T1>()));
+				}
+			};
+
+			template <typename F, typename V, typename R, typename T, typename... Types>
+			struct binary_dispatcher_lhs;
+
+			template <typename F, typename V, typename R, typename T0, typename T1, typename... Types>
+			struct binary_dispatcher_lhs<F, V, R, T0, T1, Types...>
+			{
+				VARIANT_INLINE static R apply_const(V const& lhs, V const& rhs, F&& f)
+				{
+					if (lhs.template is<T1>()) // call binary functor
+					{
+						return f(unwrapper<T1>::apply_const(lhs.template get_unchecked<T1>()),
+							unwrapper<T0>::apply_const(rhs.template get_unchecked<T0>()));
+					}
+					else
+					{
+						return binary_dispatcher_lhs<F, V, R, T0, Types...>::apply_const(lhs, rhs, std::forward<F>(f));
+					}
+				}
+
+				VARIANT_INLINE static R apply(V& lhs, V& rhs, F&& f)
+				{
+					if (lhs.template is<T1>()) // call binary functor
+					{
+						return f(unwrapper<T1>::apply(lhs.template get_unchecked<T1>()),
+							unwrapper<T0>::apply(rhs.template get_unchecked<T0>()));
+					}
+					else
+					{
+						return binary_dispatcher_lhs<F, V, R, T0, Types...>::apply(lhs, rhs, std::forward<F>(f));
+					}
+				}
+			};
+
+			template <typename F, typename V, typename R, typename T0, typename T1>
+			struct binary_dispatcher_lhs<F, V, R, T0, T1>
+			{
+				VARIANT_INLINE static R apply_const(V const& lhs, V const& rhs, F&& f)
+				{
+					return f(unwrapper<T1>::apply_const(lhs.template get_unchecked<T1>()),
+						unwrapper<T0>::apply_const(rhs.template get_unchecked<T0>()));
+				}
+
+				VARIANT_INLINE static R apply(V& lhs, V& rhs, F&& f)
+				{
+					return f(unwrapper<T1>::apply(lhs.template get_unchecked<T1>()),
+						unwrapper<T0>::apply(rhs.template get_unchecked<T0>()));
+				}
+			};
+
+			template <typename F, typename V, typename R, typename... Types>
+			struct binary_dispatcher;
+
+			template <typename F, typename V, typename R, typename T, typename... Types>
+			struct binary_dispatcher<F, V, R, T, Types...>
+			{
+				VARIANT_INLINE static R apply_const(V const& v0, V const& v1, F&& f)
+				{
+					if (v0.template is<T>())
+					{
+						if (v1.template is<T>())
+						{
+							return f(unwrapper<T>::apply_const(v0.template get_unchecked<T>()),
+								unwrapper<T>::apply_const(v1.template get_unchecked<T>())); // call binary functor
+						}
+						else
+						{
+							return binary_dispatcher_rhs<F, V, R, T, Types...>::apply_const(v0, v1, std::forward<F>(f));
+						}
+					}
+					else if (v1.template is<T>())
+					{
+						return binary_dispatcher_lhs<F, V, R, T, Types...>::apply_const(v0, v1, std::forward<F>(f));
+					}
+					return binary_dispatcher<F, V, R, Types...>::apply_const(v0, v1, std::forward<F>(f));
+				}
+
+				VARIANT_INLINE static R apply(V& v0, V& v1, F&& f)
+				{
+					if (v0.template is<T>())
+					{
+						if (v1.template is<T>())
+						{
+							return f(unwrapper<T>::apply(v0.template get_unchecked<T>()),
+								unwrapper<T>::apply(v1.template get_unchecked<T>())); // call binary functor
+						}
+						else
+						{
+							return binary_dispatcher_rhs<F, V, R, T, Types...>::apply(v0, v1, std::forward<F>(f));
+						}
+					}
+					else if (v1.template is<T>())
+					{
+						return binary_dispatcher_lhs<F, V, R, T, Types...>::apply(v0, v1, std::forward<F>(f));
+					}
+					return binary_dispatcher<F, V, R, Types...>::apply(v0, v1, std::forward<F>(f));
+				}
+			};
+
+			template <typename F, typename V, typename R, typename T>
+			struct binary_dispatcher<F, V, R, T>
+			{
+				VARIANT_INLINE static R apply_const(V const& v0, V const& v1, F&& f)
+				{
+					return f(unwrapper<T>::apply_const(v0.template get_unchecked<T>()),
+						unwrapper<T>::apply_const(v1.template get_unchecked<T>())); // call binary functor
+				}
+
+				VARIANT_INLINE static R apply(V& v0, V& v1, F&& f)
+				{
+					return f(unwrapper<T>::apply(v0.template get_unchecked<T>()),
+						unwrapper<T>::apply(v1.template get_unchecked<T>())); // call binary functor
+				}
+			};
+
+			// comparator functors
+			struct equal_comp
+			{
+				template <typename T>
+				bool operator()(T const& lhs, T const& rhs) const
+				{
+					return lhs == rhs;
+				}
+			};
+
+			struct less_comp
+			{
+				template <typename T>
+				bool operator()(T const& lhs, T const& rhs) const
+				{
+					return lhs < rhs;
+				}
+			};
+
+			template <typename Variant, typename Comp>
+			class comparer
+			{
+			public:
+				explicit comparer(Variant const& lhs) noexcept
+					: lhs_(lhs) {}
+				comparer& operator=(comparer const&) = delete;
+				// visitor
+				template <typename T>
+				bool operator()(T const& rhs_content) const
+				{
+					T const& lhs_content = lhs_.template get_unchecked<T>();
+					return Comp()(lhs_content, rhs_content);
+				}
+
+			private:
+				Variant const& lhs_;
+			};
+
+		} // namespace detail
+
+		struct no_init
+		{
+		};
+
+		template <typename... Types>
+		class variant
+		{
+			static_assert(sizeof...(Types) > 0, "Template parameter type list of variant can not be empty");
+			static_assert(!detail::disjunction<std::is_reference<Types>...>::value, "Variant can not hold reference types. Maybe use std::reference_wrapper?");
+
+		private:
+			static const std::size_t data_size = detail::static_max<sizeof(Types)...>::value;
+			static const std::size_t data_align = detail::static_max<alignof(Types)...>::value;
+
+			using first_type = typename std::tuple_element<0, std::tuple<Types...>>::type;
+			using data_type = typename std::aligned_storage<data_size, data_align>::type;
+			using helper_type = detail::variant_helper<Types...>;
+
+			std::size_t type_index;
+			data_type data;
+
+		public:
+			VARIANT_INLINE variant() noexcept(std::is_nothrow_default_constructible<first_type>::value)
+				: type_index(sizeof...(Types)-1)
+			{
+				static_assert(std::is_default_constructible<first_type>::value, "First type in variant must be default constructible to allow default construction of variant");
+				new (&data) first_type();
+			}
+
+			VARIANT_INLINE variant(no_init) noexcept
+				: type_index(detail::invalid_value) {}
+
+			// http://isocpp.org/blog/2012/11/universal-references-in-c11-scott-meyers
+			template <typename T, typename Traits = detail::value_traits<T, Types...>,
+				typename Enable = typename std::enable_if<Traits::is_valid>::type>
+				VARIANT_INLINE variant(T&& val) noexcept(std::is_nothrow_constructible<typename Traits::target_type, T&&>::value)
+				: type_index(Traits::index)
+			{
+				new (&data) typename Traits::target_type(std::forward<T>(val));
+			}
+
+			VARIANT_INLINE variant(variant<Types...> const& old)
+				: type_index(old.type_index)
+			{
+				helper_type::copy(old.type_index, &old.data, &data);
+			}
+
+			VARIANT_INLINE variant(variant<Types...>&& old) noexcept(std::is_nothrow_move_constructible<std::tuple<Types...>>::value)
+				: type_index(old.type_index)
+			{
+				helper_type::move(old.type_index, &old.data, &data);
+			}
+
+		private:
+			VARIANT_INLINE void copy_assign(variant<Types...> const& rhs)
+			{
+				helper_type::destroy(type_index, &data);
+				type_index = detail::invalid_value;
+				helper_type::copy(rhs.type_index, &rhs.data, &data);
+				type_index = rhs.type_index;
+			}
+
+			VARIANT_INLINE void move_assign(variant<Types...>&& rhs)
+			{
+				helper_type::destroy(type_index, &data);
+				type_index = detail::invalid_value;
+				helper_type::move(rhs.type_index, &rhs.data, &data);
+				type_index = rhs.type_index;
+			}
+
+		public:
+			VARIANT_INLINE variant<Types...>& operator=(variant<Types...>&& other)
+			{
+				move_assign(std::move(other));
+				return *this;
+			}
+
+			VARIANT_INLINE variant<Types...>& operator=(variant<Types...> const& other)
+			{
+				copy_assign(other);
+				return *this;
+			}
+
+			// conversions
+			// move-assign
+			template <typename T>
+			VARIANT_INLINE variant<Types...>& operator=(T&& rhs) noexcept
+			{
+				variant<Types...> temp(std::forward<T>(rhs));
+				move_assign(std::move(temp));
+				return *this;
+			}
+
+			// copy-assign
+			template <typename T>
+			VARIANT_INLINE variant<Types...>& operator=(T const& rhs)
+			{
+				variant<Types...> temp(rhs);
+				copy_assign(temp);
+				return *this;
+			}
+
+			template <typename T, typename std::enable_if<
+				(detail::direct_type<T, Types...>::index != detail::invalid_value)>::type* = nullptr>
+				VARIANT_INLINE bool is() const
+			{
+				return type_index == detail::direct_type<T, Types...>::index;
+			}
+
+			template <typename T, typename std::enable_if<
+				(detail::direct_type<recursive_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr>
+				VARIANT_INLINE bool is() const
+			{
+				return type_index == detail::direct_type<recursive_wrapper<T>, Types...>::index;
+			}
+
+			VARIANT_INLINE bool valid() const
+			{
+				return type_index != detail::invalid_value;
+			}
+
+			template <typename T, typename... Args>
+			VARIANT_INLINE void set(Args&&... args)
+			{
+				helper_type::destroy(type_index, &data);
+				type_index = detail::invalid_value;
+				new (&data) T(std::forward<Args>(args)...);
+				type_index = detail::direct_type<T, Types...>::index;
+			}
+
+			// get_unchecked<T>()
+			template <typename T, typename std::enable_if<
+				(detail::direct_type<T, Types...>::index != detail::invalid_value)>::type* = nullptr>
+				VARIANT_INLINE T& get_unchecked()
+			{
+				return *reinterpret_cast<T*>(&data);
+			}
+
+#ifdef HAS_EXCEPTIONS
+			// get<T>()
+			template <typename T, typename std::enable_if<
+				(detail::direct_type<T, Types...>::index != detail::invalid_value)>::type* = nullptr>
+				VARIANT_INLINE T& get()
+			{
+				if (type_index == detail::direct_type<T, Types...>::index)
+				{
+					return *reinterpret_cast<T*>(&data);
+				}
+				else
+				{
+					throw bad_variant_access("in get<T>()");
+				}
+			}
+#endif
+
+			template <typename T, typename std::enable_if<
+				(detail::direct_type<T, Types...>::index != detail::invalid_value)>::type* = nullptr>
+				VARIANT_INLINE T const& get_unchecked() const
+			{
+				return *reinterpret_cast<T const*>(&data);
+			}
+
+#ifdef HAS_EXCEPTIONS
+			template <typename T, typename std::enable_if<
+				(detail::direct_type<T, Types...>::index != detail::invalid_value)>::type* = nullptr>
+				VARIANT_INLINE T const& get() const
+			{
+				if (type_index == detail::direct_type<T, Types...>::index)
+				{
+					return *reinterpret_cast<T const*>(&data);
+				}
+				else
+				{
+					throw bad_variant_access("in get<T>()");
+				}
+			}
+#endif
+
+			// get_unchecked<T>() - T stored as recursive_wrapper<T>
+			template <typename T, typename std::enable_if<
+				(detail::direct_type<recursive_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr>
+				VARIANT_INLINE T& get_unchecked()
+			{
+				return (*reinterpret_cast<recursive_wrapper<T>*>(&data)).get();
+			}
+
+#ifdef HAS_EXCEPTIONS
+			// get<T>() - T stored as recursive_wrapper<T>
+			template <typename T, typename std::enable_if<
+				(detail::direct_type<recursive_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr>
+				VARIANT_INLINE T& get()
+			{
+				if (type_index == detail::direct_type<recursive_wrapper<T>, Types...>::index)
+				{
+					return (*reinterpret_cast<recursive_wrapper<T>*>(&data)).get();
+				}
+				else
+				{
+					throw bad_variant_access("in get<T>()");
+				}
+			}
+#endif
+
+			template <typename T, typename std::enable_if<
+				(detail::direct_type<recursive_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr>
+				VARIANT_INLINE T const& get_unchecked() const
+			{
+				return (*reinterpret_cast<recursive_wrapper<T> const*>(&data)).get();
+			}
+
+#ifdef HAS_EXCEPTIONS
+			template <typename T, typename std::enable_if<
+				(detail::direct_type<recursive_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr>
+				VARIANT_INLINE T const& get() const
+			{
+				if (type_index == detail::direct_type<recursive_wrapper<T>, Types...>::index)
+				{
+					return (*reinterpret_cast<recursive_wrapper<T> const*>(&data)).get();
+				}
+				else
+				{
+					throw bad_variant_access("in get<T>()");
+				}
+			}
+#endif
+
+			// get_unchecked<T>() - T stored as std::reference_wrapper<T>
+			template <typename T, typename std::enable_if<
+				(detail::direct_type<std::reference_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr>
+				VARIANT_INLINE T& get_unchecked()
+			{
+				return (*reinterpret_cast<std::reference_wrapper<T>*>(&data)).get();
+			}
+
+#ifdef HAS_EXCEPTIONS
+			// get<T>() - T stored as std::reference_wrapper<T>
+			template <typename T, typename std::enable_if<
+				(detail::direct_type<std::reference_wrapper<T>, Types...>::index != detail::invalid_value)>::type* = nullptr>
+				VARIANT_INLINE T& get()
+			{
+				if (type_index == detail::direct_type<std::reference_wrapper<T>, Types...>::index)
+				{
+					return (*reinterpret_cast<std::reference_wrapper<T>*>(&data)).get();
+				}
+				else
+				{
+					throw bad_variant_access("in get<T>()");
+				}
+			}
+#endif
+
+			template <typename T, typename std::enable_if<
+				(detail::direct_type<std::reference_wrapper<T const>, Types...>::index != detail::invalid_value)>::type* = nullptr>
+				VARIANT_INLINE T const& get_unchecked() const
+			{
+				return (*reinterpret_cast<std::reference_wrapper<T const> const*>(&data)).get();
+			}
+
+#ifdef HAS_EXCEPTIONS
+			template <typename T, typename std::enable_if<
+				(detail::direct_type<std::reference_wrapper<T const>, Types...>::index != detail::invalid_value)>::type* = nullptr>
+				VARIANT_INLINE T const& get() const
+			{
+				if (type_index == detail::direct_type<std::reference_wrapper<T const>, Types...>::index)
+				{
+					return (*reinterpret_cast<std::reference_wrapper<T const> const*>(&data)).get();
+				}
+				else
+				{
+					throw bad_variant_access("in get<T>()");
+				}
+			}
+#endif
+
+			// This function is deprecated because it returns an internal index field.
+			// Use which() instead.
+			MAPBOX_VARIANT_DEPRECATED VARIANT_INLINE std::size_t get_type_index() const
+			{
+				return type_index;
+			}
+
+			VARIANT_INLINE int which() const noexcept
+			{
+				return static_cast<int>(sizeof...(Types)-type_index - 1);
+			}
+
+			template <typename T, typename std::enable_if<
+				(detail::direct_type<T, Types...>::index != detail::invalid_value)>::type* = nullptr>
+				VARIANT_INLINE static constexpr int which() noexcept
+			{
+				return static_cast<int>(sizeof...(Types)-detail::direct_type<T, Types...>::index - 1);
+			}
+
+			// visitor
+			// unary
+			template <typename F, typename V, typename R = typename detail::result_of_unary_visit<F, first_type>::type>
+			auto VARIANT_INLINE static visit(V const& v, F&& f)
+				-> decltype(detail::dispatcher<F, V, R, Types...>::apply_const(v, std::forward<F>(f)))
+			{
+				return detail::dispatcher<F, V, R, Types...>::apply_const(v, std::forward<F>(f));
+			}
+			// non-const
+			template <typename F, typename V, typename R = typename detail::result_of_unary_visit<F, first_type>::type>
+			auto VARIANT_INLINE static visit(V& v, F&& f)
+				-> decltype(detail::dispatcher<F, V, R, Types...>::apply(v, std::forward<F>(f)))
+			{
+				return detail::dispatcher<F, V, R, Types...>::apply(v, std::forward<F>(f));
+			}
+
+			// binary
+			// const
+			template <typename F, typename V, typename R = typename detail::result_of_binary_visit<F, first_type>::type>
+			auto VARIANT_INLINE static binary_visit(V const& v0, V const& v1, F&& f)
+				-> decltype(detail::binary_dispatcher<F, V, R, Types...>::apply_const(v0, v1, std::forward<F>(f)))
+			{
+				return detail::binary_dispatcher<F, V, R, Types...>::apply_const(v0, v1, std::forward<F>(f));
+			}
+			// non-const
+			template <typename F, typename V, typename R = typename detail::result_of_binary_visit<F, first_type>::type>
+			auto VARIANT_INLINE static binary_visit(V& v0, V& v1, F&& f)
+				-> decltype(detail::binary_dispatcher<F, V, R, Types...>::apply(v0, v1, std::forward<F>(f)))
+			{
+				return detail::binary_dispatcher<F, V, R, Types...>::apply(v0, v1, std::forward<F>(f));
+			}
+
+			~variant() noexcept // no-throw destructor
+			{
+				helper_type::destroy(type_index, &data);
+			}
+
+			// comparison operators
+			// equality
+			VARIANT_INLINE bool operator==(variant const& rhs) const
+			{
+				assert(valid() && rhs.valid());
+				if (this->which() != rhs.which())
+				{
+					return false;
+				}
+				detail::comparer<variant, detail::equal_comp> visitor(*this);
+				return visit(rhs, visitor);
+			}
+
+			VARIANT_INLINE bool operator!=(variant const& rhs) const
+			{
+				return !(*this == rhs);
+			}
+
+			// less than
+			VARIANT_INLINE bool operator<(variant const& rhs) const
+			{
+				assert(valid() && rhs.valid());
+				if (this->which() != rhs.which())
+				{
+					return this->which() < rhs.which();
+				}
+				detail::comparer<variant, detail::less_comp> visitor(*this);
+				return visit(rhs, visitor);
+			}
+			VARIANT_INLINE bool operator>(variant const& rhs) const
+			{
+				return rhs < *this;
+			}
+			VARIANT_INLINE bool operator<=(variant const& rhs) const
+			{
+				return !(*this > rhs);
+			}
+			VARIANT_INLINE bool operator>=(variant const& rhs) const
+			{
+				return !(*this < rhs);
+			}
+		};
+
+		// unary visitor interface
+		// const
+		template <typename F, typename V>
+		auto VARIANT_INLINE apply_visitor(F&& f, V const& v) -> decltype(V::visit(v, std::forward<F>(f)))
+		{
+			return V::visit(v, std::forward<F>(f));
+		}
+
+		// non-const
+		template <typename F, typename V>
+		auto VARIANT_INLINE apply_visitor(F&& f, V& v) -> decltype(V::visit(v, std::forward<F>(f)))
+		{
+			return V::visit(v, std::forward<F>(f));
+		}
+
+		// binary visitor interface
+		// const
+		template <typename F, typename V>
+		auto VARIANT_INLINE apply_visitor(F&& f, V const& v0, V const& v1) -> decltype(V::binary_visit(v0, v1, std::forward<F>(f)))
+		{
+			return V::binary_visit(v0, v1, std::forward<F>(f));
+		}
+
+		// non-const
+		template <typename F, typename V>
+		auto VARIANT_INLINE apply_visitor(F&& f, V& v0, V& v1) -> decltype(V::binary_visit(v0, v1, std::forward<F>(f)))
+		{
+			return V::binary_visit(v0, v1, std::forward<F>(f));
+		}
+
+		// getter interface
+
+#ifdef HAS_EXCEPTIONS
+		template <typename ResultType, typename T>
+		auto get(T& var)->decltype(var.template get<ResultType>())
+		{
+			return var.template get<ResultType>();
+		}
+#endif
+
+		template <typename ResultType, typename T>
+		ResultType& get_unchecked(T& var)
+		{
+			return var.template get_unchecked<ResultType>();
+		}
+
+#ifdef HAS_EXCEPTIONS
+		template <typename ResultType, typename T>
+		auto get(T const& var)->decltype(var.template get<ResultType>())
+		{
+			return var.template get<ResultType>();
+		}
+#endif
+
+		template <typename ResultType, typename T>
+		ResultType const& get_unchecked(T const& var)
+		{
+			return var.template get_unchecked<ResultType>();
+		}
+	}
+//	} // namespace util
+//} // namespace mapbox
+
+#endif // MAPBOX_UTIL_VARIANT_HPP
\ No newline at end of file