diff options
Diffstat (limited to 'include/llmr/util/variant.hpp')
| -rw-r--r-- | include/llmr/util/variant.hpp | 453 |
1 files changed, 339 insertions, 114 deletions
diff --git a/include/llmr/util/variant.hpp b/include/llmr/util/variant.hpp index b887ae494d..57f8593439 100644 --- a/include/llmr/util/variant.hpp +++ b/include/llmr/util/variant.hpp @@ -1,5 +1,5 @@ -#ifndef UTIL_VARIANT_HPP -#define UTIL_VARIANT_HPP +#ifndef MAPBOX_UTIL_VARIANT_HPP +#define MAPBOX_UTIL_VARIANT_HPP #include <utility> #include <typeinfo> @@ -9,50 +9,119 @@ #include <new> // operator new #include <cstddef> // size_t #include <iosfwd> +#include <string> -#ifdef NDEBUG -#define VARIANT_INLINE inline __attribute__((always_inline)) +#include "recursive_wrapper.hpp" + +#ifdef _MSC_VER + // http://msdn.microsoft.com/en-us/library/z8y1yy88.aspx + #ifdef NDEBUG + #define VARIANT_INLINE __forceinline + #else + #define VARIANT_INLINE __declspec(noinline) + #endif #else -#define VARIANT_INLINE __attribute__((noinline)) + #ifdef NDEBUG + #define VARIANT_INLINE inline __attribute__((always_inline)) + #else + #define VARIANT_INLINE __attribute__((noinline)) + #endif #endif -namespace llmr { +#define VARIANT_MAJOR_VERSION 0 +#define VARIANT_MINOR_VERSION 1 +#define VARIANT_PATCH_VERSION 0 -namespace util { +// translates to 100 +#define VARIANT_VERSION (VARIANT_MAJOR_VERSION*100000) + (VARIANT_MINOR_VERSION*100) + (VARIANT_PATCH_VERSION) -namespace detail { +namespace llmr { namespace util { namespace detail { static constexpr std::size_t invalid_value = std::size_t(-1); template <typename T, typename...Types> -struct type_traits; +struct direct_type; template <typename T, typename First, typename...Types> -struct type_traits<T, First, Types...> +struct direct_type<T, First, Types...> { - static constexpr std::size_t id = std::is_same<T, First>::value ? sizeof...(Types) : type_traits<T, Types...>::id; + static constexpr std::size_t index = std::is_same<T, First>::value + ? sizeof...(Types) : direct_type<T, Types...>::index; }; template <typename T> -struct type_traits<T> +struct direct_type<T> { - static constexpr std::size_t id = invalid_value; + static constexpr std::size_t index = invalid_value; +}; + +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 + ? 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 +{ + static constexpr std::size_t direct_index = direct_type<T, Types...>::index; + static constexpr std::size_t index = + (direct_index == invalid_value) ? convertible_type<T, Types...>::index : direct_index; }; template <typename T, typename...Types> struct is_valid_type; template <typename T, typename First, typename... Types> -struct is_valid_type<T,First,Types...> +struct is_valid_type<T, First, Types...> { - static constexpr bool value = std::is_same<T,First>::value - || is_valid_type<T,Types...>::value; + static constexpr bool value = std::is_convertible<T, First>::value + || is_valid_type<T, Types...>::value; }; template <typename T> struct is_valid_type<T> : std::false_type {}; -} +template <std::size_t N, typename ... Types> +struct select_type +{ + static_assert(N < sizeof...(Types), "index out of bounds"); +}; + +template <std::size_t N, typename T, typename ... Types> +struct select_type<N, T, Types...> +{ + using type = typename select_type<N - 1, Types...>::type; +}; + +template <typename T, typename ... Types> +struct select_type<0, T, Types...> +{ + using type = T; +}; + +} // namespace detail + +// static visitor +template <typename R = void> +struct static_visitor +{ + using result_type = R; +protected: + static_visitor() {} + ~static_visitor() {} +}; + template <std::size_t arg1, std::size_t ... others> struct static_max; @@ -125,37 +194,77 @@ template<> struct variant_helper<> namespace detail { +template <typename T> +struct unwrapper +{ + T const& operator() (T const& obj) const + { + return obj; + } + + T& operator() (T & obj) const + { + return obj; + } +}; + + +template <typename T> +struct unwrapper<recursive_wrapper<T>> +{ + auto operator() (recursive_wrapper<T> const& obj) const + -> typename recursive_wrapper<T>::type const& + { + return obj.get(); + } +}; + + template <typename F, typename V, typename...Types> struct dispatcher; template <typename F, typename V, typename T, typename...Types> -struct dispatcher<F,V,T,Types...> +struct dispatcher<F, V, T, Types...> { - typedef typename std::result_of<F(V const&)>::type result_type; + using result_type = typename F::result_type; + VARIANT_INLINE static result_type apply_const(V const& v, F f) + { + if (v.get_type_index() == sizeof...(Types)) + { + return f(unwrapper<T>()(v. template get<T>())); + } + else + { + return dispatcher<F, V, Types...>::apply_const(v, f); + } + } - VARIANT_INLINE static result_type apply(V const& v, F f) + VARIANT_INLINE static result_type apply(V & v, F f) { - if (v.get_type_id() == sizeof...(Types)) + if (v.get_type_index() == sizeof...(Types)) { - return f(v. template get<T>()); + return f(unwrapper<T>()(v. template get<T>())); } else { - return dispatcher<F,V,Types...>::apply(v, f); + return dispatcher<F, V, Types...>::apply(v, f); } } }; -template<typename F,typename V> -struct dispatcher<F,V> +template<typename F, typename V> +struct dispatcher<F, V> { - typedef typename std::result_of<F(V const&)>::type result_type; - - VARIANT_INLINE static result_type apply(V const&, F) + using result_type = typename F::result_type; + VARIANT_INLINE static result_type apply_const(V const&, F) { - throw std::runtime_error("unary dispatch: FAIL"); + throw std::runtime_error(std::string("unary dispatch: FAIL ") + typeid(V).name()); } + VARIANT_INLINE static result_type apply(V &, F) + { + throw std::runtime_error(std::string("unary dispatch: FAIL ") + typeid(V).name()); + } }; @@ -163,28 +272,46 @@ template <typename F, typename V, typename T, typename...Types> struct binary_dispatcher_rhs; template <typename F, typename V, typename T0, typename T1, typename...Types> -struct binary_dispatcher_rhs<F,V,T0,T1,Types...> +struct binary_dispatcher_rhs<F, V, T0, T1, Types...> { - typedef typename std::result_of<F(V const&, V const&)>::type result_type; - VARIANT_INLINE static result_type apply(V const& lhs, V const& rhs, F f) + using result_type = typename F::result_type; + VARIANT_INLINE static result_type apply_const(V const& lhs, V const& rhs, F f) + { + if (rhs.get_type_index() == sizeof...(Types)) // call binary functor + { + return f(unwrapper<T0>()(lhs. template get<T0>()), + unwrapper<T1>()(rhs. template get<T1>())); + } + else + { + return binary_dispatcher_rhs<F, V, T0, Types...>::apply_const(lhs, rhs, f); + } + } + + VARIANT_INLINE static result_type apply(V & lhs, V & rhs, F f) { - if (rhs.get_type_id() == sizeof...(Types)) // call binary functor + if (rhs.get_type_index() == sizeof...(Types)) // call binary functor { - return f(lhs. template get<T0>(), rhs. template get<T1>()); + return f(unwrapper<T0>()(lhs. template get<T0>()), + unwrapper<T1>()(rhs. template get<T1>())); } else { - return binary_dispatcher_rhs<F,V,T0,Types...>::apply(lhs, rhs, f); + return binary_dispatcher_rhs<F, V, T0, Types...>::apply(lhs, rhs, f); } } + }; -template<typename F,typename V, typename T> -struct binary_dispatcher_rhs<F,V,T> +template<typename F, typename V, typename T> +struct binary_dispatcher_rhs<F, V, T> { - typedef typename std::result_of<F(V const&, V const&)>::type result_type; - - VARIANT_INLINE static result_type apply(V const&, V const&, F) + using result_type = typename F::result_type; + VARIANT_INLINE static result_type apply_const(V const&, V const&, F) + { + throw std::runtime_error("binary dispatch: FAIL"); + } + VARIANT_INLINE static result_type apply(V &, V &, F) { throw std::runtime_error("binary dispatch: FAIL"); } @@ -195,28 +322,45 @@ template <typename F, typename V, typename T, typename...Types> struct binary_dispatcher_lhs; template <typename F, typename V, typename T0, typename T1, typename...Types> -struct binary_dispatcher_lhs<F,V,T0,T1,Types...> +struct binary_dispatcher_lhs<F, V, T0, T1, Types...> { - typedef typename std::result_of<F(V const&, V const&)>::type binary_result_type; - VARIANT_INLINE static binary_result_type apply(V const& lhs, V const& rhs, F f) + using result_type = typename F::result_type; + VARIANT_INLINE static result_type apply_const(V const& lhs, V const& rhs, F f) { - if (lhs.get_type_id() == sizeof...(Types)) // call binary functor + if (lhs.get_type_index() == sizeof...(Types)) // call binary functor { return f(lhs. template get<T1>(), rhs. template get<T0>()); } else { - return binary_dispatcher_lhs<F,V,T0,Types...>::apply(lhs, rhs, f); + return binary_dispatcher_lhs<F, V, T0, Types...>::apply_const(lhs, rhs, f); } } + + VARIANT_INLINE static result_type apply(V & lhs, V & rhs, F f) + { + if (lhs.get_type_index() == sizeof...(Types)) // call binary functor + { + return f(lhs. template get<T1>(), rhs. template get<T0>()); + } + else + { + return binary_dispatcher_lhs<F, V, T0, Types...>::apply(lhs, rhs, f); + } + } + }; -template<typename F,typename V, typename T> -struct binary_dispatcher_lhs<F,V,T> +template<typename F, typename V, typename T> +struct binary_dispatcher_lhs<F, V, T> { - typedef typename std::result_of<F(V const&, V const&)>::type result_type; + using result_type = typename F::result_type; + VARIANT_INLINE static result_type apply_const(V const&, V const&, F) + { + throw std::runtime_error("binary dispatch: FAIL"); + } - VARIANT_INLINE static result_type apply(V const&, V const&, F) + VARIANT_INLINE static result_type apply(V &, V &, F) { throw std::runtime_error("binary dispatch: FAIL"); } @@ -226,37 +370,60 @@ template <typename F, typename V, typename...Types> struct binary_dispatcher; template <typename F, typename V, typename T, typename...Types> -struct binary_dispatcher<F,V,T,Types...> +struct binary_dispatcher<F, V, T, Types...> { - typedef typename std::result_of<F(V const&, V const&)>::type binary_result_type; + using result_type = typename F::result_type; + VARIANT_INLINE static result_type apply_const(V const& v0, V const& v1, F f) + { + if (v0.get_type_index() == sizeof...(Types)) + { + if (v0.get_type_index() == v1.get_type_index()) + { + return f(v0. template get<T>(), v1. template get<T>()); // call binary functor + } + else + { + return binary_dispatcher_rhs<F, V, T, Types...>::apply_const(v0, v1, f); + } + } + else if (v1.get_type_index() == sizeof...(Types)) + { + return binary_dispatcher_lhs<F, V, T, Types...>::apply_const(v0, v1, f); + } + return binary_dispatcher<F, V, Types...>::apply_const(v0, v1, f); + } - VARIANT_INLINE static binary_result_type apply(V const& v0, V const& v1, F f) + VARIANT_INLINE static result_type apply(V & v0, V & v1, F f) { - if (v0.get_type_id() == sizeof...(Types)) + if (v0.get_type_index() == sizeof...(Types)) { - if (v0.get_type_id() == v1.get_type_id()) + if (v0.get_type_index() == v1.get_type_index()) { return f(v0. template get<T>(), v1. template get<T>()); // call binary functor } else { - return binary_dispatcher_rhs<F,V,T,Types...>::apply(v0, v1, f); + return binary_dispatcher_rhs<F, V, T, Types...>::apply(v0, v1, f); } } - else if (v1.get_type_id() == sizeof...(Types)) + else if (v1.get_type_index() == sizeof...(Types)) { - return binary_dispatcher_lhs<F,V,T,Types...>::apply(v0, v1, f); + return binary_dispatcher_lhs<F, V, T, Types...>::apply(v0, v1, f); } - return binary_dispatcher<F,V,Types...>::apply(v0, v1, f); + return binary_dispatcher<F, V, Types...>::apply(v0, v1, f); } }; -template<typename F,typename V> -struct binary_dispatcher<F,V> +template<typename F, typename V> +struct binary_dispatcher<F, V> { - typedef typename std::result_of<F(V const&, V const&)>::type binary_result_type; + using result_type = typename F::result_type; + VARIANT_INLINE static result_type apply_const(V const&, V const&, F) + { + throw std::runtime_error("binary dispatch: FAIL"); + } - VARIANT_INLINE static binary_result_type apply(V const&, V const&, F) + VARIANT_INLINE static result_type apply(V &, V &, F) { throw std::runtime_error("binary dispatch: FAIL"); } @@ -275,19 +442,19 @@ struct equal_comp struct less_comp { template <typename T> - bool operator()(const T& lhs, const T& rhs) const + bool operator()(T const& lhs, T const& rhs) const { return lhs < rhs; } }; template <typename Variant, typename Comp> -class comparer +class comparer : public static_visitor<bool> { public: explicit comparer(Variant const& lhs) noexcept : lhs_(lhs) {} - comparer& operator=(const comparer&) = delete; + comparer& operator=(comparer const&) = delete; // visitor template<typename T> bool operator()(T const& rhs_content) const @@ -301,16 +468,16 @@ private: // operator<< helper template <typename Out> -class printer +class printer : public static_visitor<> { public: explicit printer(Out & out) : out_(out) {} - printer& operator=(printer const &) = delete; + printer& operator=(printer const&) = delete; // visitor template <typename T> - void operator()( T const & operand) const + void operator()(T const& operand) const { out_ << operand; } @@ -318,7 +485,7 @@ private: Out & out_; }; -} // detail +} // namespace detail template<typename... Types> class variant @@ -329,81 +496,106 @@ private: static const std::size_t data_align = static_max<alignof(Types)...>::value; using data_type = typename std::aligned_storage<data_size, data_align>::type; - using helper_type = variant_helper<Types...>; - std::size_t type_id; + std::size_t type_index; data_type data; public: VARIANT_INLINE variant() - : type_id(detail::invalid_value) {} + : type_index(sizeof...(Types) - 1) + { + new (&data) typename detail::select_type<0, Types...>::type(); + } - template <typename T> + template <typename T, class = typename std::enable_if< + detail::is_valid_type<T, Types...>::value>::type> VARIANT_INLINE explicit variant(T const& val) noexcept - : type_id(detail::type_traits<T, Types...>::id) + : type_index(detail::value_traits<T, Types...>::index) { - static_assert(detail::is_valid_type<T,Types...>::value, "Not a valid type for this variant"); - new (&data) T(val); + constexpr std::size_t index = sizeof...(Types) - detail::value_traits<T, Types...>::index - 1; + using target_type = typename detail::select_type<index, Types...>::type; + new (&data) target_type(val); } - template <typename T> + template <typename T, class = typename std::enable_if< + detail::is_valid_type<T, Types...>::value>::type> VARIANT_INLINE variant(T && val) noexcept - : type_id(detail::type_traits<T,Types...>::id) + : type_index(detail::value_traits<T, Types...>::index) { - static_assert(detail::is_valid_type<T,Types...>::value, "Not a valid type for this variant"); - new (&data) T(std::forward<T>(val)); // nothrow + constexpr std::size_t index = sizeof...(Types) - detail::value_traits<T, Types...>::index - 1; + using target_type = typename detail::select_type<index, Types...>::type; + new (&data) target_type(std::forward<T>(val)); // nothrow } VARIANT_INLINE variant(variant<Types...> const& old) - : type_id(old.type_id) + : type_index(old.type_index) { - helper_type::copy(old.type_id, &old.data, &data); + helper_type::copy(old.type_index, &old.data, &data); } VARIANT_INLINE variant(variant<Types...>&& old) noexcept - : type_id(old.type_id) + : type_index(old.type_index) { - helper_type::move(old.type_id, &old.data, &data); + helper_type::move(old.type_index, &old.data, &data); } friend void swap(variant<Types...> & first, variant<Types...> & second) { using std::swap; //enable ADL - swap(first.type_id, second.type_id); + swap(first.type_index, second.type_index); swap(first.data, second.data); } - VARIANT_INLINE variant<Types...>& operator= (variant<Types...> other) + VARIANT_INLINE variant<Types...>& operator=(variant<Types...> other) { swap(*this, other); return *this; } + // conversions + // move-assign + template <typename T> + VARIANT_INLINE variant<Types...>& operator=(T && rhs) noexcept + { + variant<Types...> temp(std::move(rhs)); + swap(*this, temp); + return *this; + } + + // copy-assign + template <typename T> + VARIANT_INLINE variant<Types...>& operator=(T const& rhs) + { + variant<Types...> temp(rhs); + swap(*this, temp); + return *this; + } + template<typename T> VARIANT_INLINE bool is() const { - return (type_id == detail::type_traits<T, Types...>::id); + return (type_index == detail::direct_type<T, Types...>::index); } VARIANT_INLINE bool valid() const { - return (type_id != detail::invalid_value); + return (type_index != detail::invalid_value); } template<typename T, typename... Args> VARIANT_INLINE void set(Args&&... args) { - helper_type::destroy(type_id, &data); + helper_type::destroy(type_index, &data); new (&data) T(std::forward<Args>(args)...); - type_id = detail::type_traits<T,Types...>::id; + type_index = detail::direct_type<T, Types...>::index; } template<typename T> VARIANT_INLINE T& get() { - if (type_id == detail::type_traits<T,Types...>::id) + if (type_index == detail::direct_type<T, Types...>::index) { return *reinterpret_cast<T*>(&data); } @@ -416,7 +608,7 @@ public: template<typename T> VARIANT_INLINE T const& get() const { - if (type_id == detail::type_traits<T,Types...>::id) + if (type_index == detail::direct_type<T, Types...>::index) { return *reinterpret_cast<T const*>(&data); } @@ -426,37 +618,57 @@ public: } } - VARIANT_INLINE std::size_t get_type_id() const + VARIANT_INLINE std::size_t get_type_index() const { - return type_id; + return type_index; } // visitor // unary template <typename F, typename V> - typename std::result_of<F(V const&)>::type - VARIANT_INLINE static visit(V const& v, F f) + auto VARIANT_INLINE + static visit(V const& v, F f) + -> decltype(detail::dispatcher<F, V, Types...>::apply_const(v, f)) + { + return detail::dispatcher<F, V, Types...>::apply_const(v, f); + } + // non-const + template <typename F, typename V> + auto VARIANT_INLINE + static visit(V & v, F f) + -> decltype(detail::dispatcher<F, V, Types...>::apply(v, f)) { return detail::dispatcher<F, V, Types...>::apply(v, f); } + // binary + // const + template <typename F, typename V> + auto VARIANT_INLINE + static binary_visit(V const& v0, V const& v1, F f) + -> decltype(detail::binary_dispatcher<F, V, Types...>::apply_const(v0, v1, f)) + { + return detail::binary_dispatcher<F, V, Types...>::apply_const(v0, v1, f); + } + // non-const template <typename F, typename V> - typename std::result_of<F(V const&, V const& )>::type - VARIANT_INLINE static binary_visit(V const& v0, V const& v1, F f) + auto VARIANT_INLINE + static binary_visit(V& v0, V& v1, F f) + -> decltype(detail::binary_dispatcher<F, V, Types...>::apply(v0, v1, f)) { return detail::binary_dispatcher<F, V, Types...>::apply(v0, v1, f); } ~variant() noexcept { - helper_type::destroy(type_id, &data); + helper_type::destroy(type_index, &data); } // comparison operators // equality VARIANT_INLINE bool operator==(variant const& rhs) const { - if (this->get_type_id() != rhs.get_type_id()) + if (this->get_type_index() != rhs.get_type_index()) return false; detail::comparer<variant, detail::equal_comp> visitor(*this); return visit(rhs, visitor); @@ -464,9 +676,9 @@ public: // less than VARIANT_INLINE bool operator<(variant const& rhs) const { - if (this->get_type_id() != rhs.get_type_id()) + if (this->get_type_index() != rhs.get_type_index()) { - return this->get_type_id() < rhs.get_type_id(); + return this->get_type_index() < rhs.get_type_index(); // ^^ borrowed from boost::variant } detail::comparer<variant, detail::less_comp> visitor(*this); @@ -475,17 +687,30 @@ public: }; // unary visitor interface + +// const +template <typename V, typename F> +auto VARIANT_INLINE static apply_visitor(F f, V const& v) -> decltype(V::visit(v, f)) +{ + return V::visit(v, f); +} +// non-const template <typename V, typename F> -typename std::result_of<F(V const&)>::type -VARIANT_INLINE static apply_visitor(V const& v, F f) +auto VARIANT_INLINE static apply_visitor(F f, V & v) -> decltype(V::visit(v, f)) { - return V::visit(v,f); + return V::visit(v, f); } // binary visitor interface +// const +template <typename V, typename F> +auto VARIANT_INLINE static apply_visitor(F f, V const& v0, V const& v1) -> decltype(V::binary_visit(v0, v1, f)) +{ + return V::binary_visit(v0, v1, f); +} +// non-const template <typename V, typename F> -typename std::result_of<F(V const&, V const&)>::type -VARIANT_INLINE static apply_visitor(V const& v0, V const& v1, F f) +auto VARIANT_INLINE static apply_visitor(F f, V & v0, V & v1) -> decltype(V::binary_visit(v0, v1, f)) { return V::binary_visit(v0, v1, f); } @@ -493,14 +718,14 @@ VARIANT_INLINE static apply_visitor(V const& v0, V const& v1, F f) // operator<< template <typename charT, typename traits, typename Variant> -VARIANT_INLINE std::basic_ostream<charT,traits>& -operator<< (std::basic_ostream<charT,traits>& out, Variant const& rhs) +VARIANT_INLINE std::basic_ostream<charT, traits>& +operator<< (std::basic_ostream<charT, traits>& out, Variant const& rhs) { - detail::printer<std::basic_ostream<charT,traits> > visitor(out); - apply_visitor(rhs, visitor); + detail::printer<std::basic_ostream<charT, traits>> visitor(out); + apply_visitor(visitor, rhs); return out; } -} -} -#endif // UTIL_VARIANT_HPP +}} + +#endif // MAPBOX_UTIL_VARIANT_HPP |