partial variant

CMakeLists.txt

@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.20)
 include(cmake/color.cmake)
-set(BLT_VERSION 5.4.5)
+set(BLT_VERSION 5.4.6)
 
 set(BLT_TARGET BLT)
 
@@ -238,6 +238,7 @@ if (${BUILD_TESTS})
     blt_add_test(blt_iterator tests/iterator_tests.cpp test)
     blt_add_test(blt_argparse tests/argparse_tests.cpp test)
     blt_add_test(blt_logging tests/logger_tests.cpp test)
+    blt_add_test(blt_variant tests/variant_tests.cpp test)
 
     message("Built tests")
 endif ()

include/blt/std/variant.h

@@ -21,10 +21,10 @@
 
 #include <functional>
 #include <optional>
+#include <tuple>
 #include <type_traits>
 #include <variant>
 #include <blt/std/types.h>
-#include <tuple>
 
 namespace blt
 {
@@ -45,19 +45,33 @@ namespace blt
 		template <typename T, typename... Ts>
 		struct filter_void<T, Ts...>
 		{
-            using type = std::conditional_t<
+			using type = std::conditional_t<std::is_same_v<T, void>, typename filter_void<Ts...>::type, decltype(std::tuple_cat(
-                std::is_same_v<T, void>,
+												std::declval<std::tuple<T>>(), std::declval<typename filter_void<Ts...>::type>()))>;
-                typename filter_void<Ts...>::type,
-                decltype(std::tuple_cat(
-                    std::declval<std::tuple<T>>(),
-                    std::declval<typename filter_void<Ts...>::type>()
-                ))
-            >;
 		};
 
 		template <typename... Ts>
 		using filter_void_t = typename filter_void<Ts...>::type;
 
+		template <typename Type, typename... Ts>
+		struct filter_invoke;
+
+		template <typename Type>
+		struct filter_invoke<Type>
+		{
+			using type = std::tuple<>;
+		};
+
+		template <typename Type, typename T, typename... Ts>
+		struct filter_invoke<Type, T, Ts...>
+		{
+			using type = std::conditional_t<std::is_invocable_v<T, Type>, decltype(std::tuple_cat(
+												std::declval<std::tuple<T>>(), std::declval<typename filter_invoke<Ts...>::type>())),
+											typename filter_invoke<Ts...>::type>;
+		};
+
+		template <typename... Ts>
+		using filter_invoke_t = typename filter_invoke<Ts...>::type;
+
 		template <typename Type, typename Func>
 		struct member_func_meta
 		{
@@ -66,16 +80,21 @@ namespace blt
 			using return_type = std::conditional_t<can_invoke::value, std::invoke_result_t<Func, Type>, void>;
 		};
 
-        template <typename T, typename Func, size_t Index, bool HasValue>
+		template <typename T, typename Func, size_t Index>
 		struct passthrough_value
 		{
 			using type = T;
 			using func = Func;
 			constexpr static size_t index = Index;
 
+			bool has_value;
+
+			explicit passthrough_value(const bool has_value): has_value(has_value)
+			{}
+
 			explicit operator bool() const
 			{
-                return HasValue;
+				return has_value;
 			}
 		};
 
@@ -85,14 +104,13 @@ namespace blt
 			template <size_t... Indexes>
 			constexpr static auto find_func(std::index_sequence<Indexes...>)
 			{
-                return (... || []()
+				return (... || []() {
-                {
 					using Meta = member_func_meta<Type, Funcs>;
 					if constexpr (Meta::can_invoke::value)
 					{
-                        return passthrough_value<typename Meta::return_type, Funcs, Indexes, true>{};
+						return passthrough_value<typename Meta::return_type, Funcs, Indexes>{true};
 					}
-                    return passthrough_value<void, Funcs, Indexes, false>{};
+					return passthrough_value<typename Meta::return_type, Funcs, Indexes>{false};
 				}());
 			}
 
@@ -103,56 +121,51 @@ namespace blt
 		};
 
 		template <typename FuncTuple, typename ArgTuple>
-        struct member_func_detail
+		struct member_func_detail;
-        {
-        };
 
 		template <typename... Funcs, typename... Args>
 		struct member_func_detail<std::tuple<Funcs...>, std::tuple<Args...>>
 		{
 			using result_types = std::tuple<first_invoke_member_func<Args, Funcs...>...>;
-            using base_type = typename decltype(std::get<0>(std::declval<result_types>))::type;
+			using base_type = typename std::tuple_element_t<0, result_types>::return_type;
 
 			template <typename T>
-            using get_type = typename T::type;
+			using get_type = typename T::return_type;
 
 			template <typename T>
-            using is_base = std::is_same<typename T::type, base_type>;
+			using is_base = std::is_same<T, base_type>;
 
 			template <typename T>
-            using is_base_or_void = std::disjunction<std::is_void<typename T::type>, is_base<typename T::type>>;
+			using is_base_or_void = std::disjunction<std::is_void<typename T::return_type>, is_base<typename T::return_type>>;
 
 			template <template<typename...> typename Functor, template<typename> typename PerType, size_t... Indexes>
 			constexpr static auto for_each_type(std::index_sequence<Indexes...>)
 			{
-                return std::declval<Functor<PerType<decltype(std::get<Indexes>(std::declval<result_types>()))>...>>;
+				return std::declval<Functor<PerType<std::tuple_element_t<Indexes, result_types>>...>>;
 			}
 
-            constexpr static bool all_has_void = for_each_type<std::conjunction_v, std::is_void>(std::index_sequence_for<Args...>());
+			constexpr static bool all_has_void = std::decay_t<std::invoke_result_t<decltype(for_each_type<std::conjunction, std::is_void>(
-            constexpr static bool all_has_ret = for_each_type<std::conjunction_v, is_base>(std::index_sequence_for<Args...>());
+				std::index_sequence_for<Args...>()))>>::value;
-            constexpr static bool all_has_ret_or_void = for_each_type<std::conjunction_v, is_base_or_void>(std::index_sequence_for<Args...>());
+			constexpr static bool all_has_ret = std::decay_t<std::invoke_result_t<decltype(for_each_type<std::conjunction, is_base>(
+				std::index_sequence_for<Args...>()))>>::value;
+			constexpr static bool all_has_ret_or_void = std::decay_t<std::invoke_result_t<decltype(for_each_type<std::conjunction, is_base_or_void>(
+				std::index_sequence_for<Args...>()))>>::value;
 
-            using non_void_types = typename decltype(for_each_type<filter_void_t, get_type>(std::index_sequence_for<Args...>()))::type;
+			using non_void_types = typename std::decay_t<std::invoke_result_t<decltype(for_each_type<filter_void, get_type>(
+				std::index_sequence_for<Args...>()))>>::type;
 
 			template <size_t... Indexes>
 			static constexpr auto make_variant(std::index_sequence<Indexes...>)
 			{
-                if constexpr (all_has_void)
+				using variant = variant_t<std::decay_t<std::tuple_element_t<Indexes, non_void_types>>...>;
-                    return;
-                using variant = variant_t<decltype(std::get<Indexes>(std::declval<non_void_types>()))...>;
 				return std::declval<variant>();
 			}
 
-            static constexpr auto make_return_type()
+			using make_return_type = std::conditional_t<all_has_void, void, std::conditional_t<
-            {
+															all_has_ret, base_type, std::conditional_t<
-                if constexpr (all_has_void)
+																all_has_ret_or_void, std::optional<base_type>, std::conditional_t<
-                    return;
+																	std::tuple_size_v<non_void_types> == 0, void, decltype(make_variant(
-                if constexpr (all_has_ret)
+																		std::make_index_sequence<std::tuple_size_v<non_void_types>>{}))>>>>;
-                    return std::declval<base_type>();
-                if constexpr (all_has_ret_or_void)
-                    return std::declval<std::optional<base_type>>();
-                return make_variant(std::make_index_sequence<std::tuple_size_v<non_void_types>>{});
-            }
 		};
 	}
 
@@ -168,13 +181,13 @@ namespace blt
 		using TLambdas::operator()...;
 	};
 
-#if __cplusplus < 202002L
+	#if __cplusplus < 202002L
 
 	// explicit deduction guide (not needed as of C++20)
 	template <typename... TLambdas>
 	lambda_visitor(TLambdas...) -> lambda_visitor<TLambdas...>;
 
-#endif
+	#endif
 
 	template <typename... Types>
 	class variant_t
@@ -184,51 +197,41 @@ namespace blt
 		size_t variant_size = sizeof...(Types);
 
 		constexpr variant_t(): m_variant()
-        {
+		{}
-        }
 
 		constexpr variant_t(const variant_t& variant) noexcept(std::is_nothrow_copy_constructible_v<value_type>): m_variant(variant.m_variant)
-        {
+		{}
-        }
 
 		constexpr variant_t(variant_t&& variant) noexcept(std::is_nothrow_move_constructible_v<value_type>): m_variant(std::move(variant.m_variant))
-        {
+		{}
-        }
 
 		explicit constexpr variant_t(const value_type& variant) noexcept(std::is_nothrow_copy_constructible_v<value_type>): m_variant(variant)
-        {
+		{}
-        }
 
 		explicit constexpr variant_t(value_type&& variant) noexcept(std::is_nothrow_move_constructible_v<value_type>): m_variant(std::move(variant))
-        {
+		{}
-        }
 
 		explicit constexpr variant_t(Types&&... args) noexcept(std::is_nothrow_constructible_v<value_type, Types...>): m_variant(
 			std::forward<Types>(args)...)
-        {
+		{}
-        }
 
 		template <typename T, typename... C_Args>
 		explicit constexpr variant_t(std::in_place_type_t<T>, C_Args&&... args): m_variant(std::in_place_type<T>, std::forward<C_Args>(args)...)
-        {
+		{}
-        }
 
 		template <typename T, typename U, typename... C_Args>
 		constexpr explicit variant_t(std::in_place_type_t<T>, std::initializer_list<U> il, C_Args&&... args): m_variant(
 			std::in_place_type<T>, il, std::forward<C_Args>(args)...)
-        {
+		{}
-        }
 
 		template <size_t I, typename... C_Args>
 		explicit constexpr variant_t(std::in_place_index_t<I>, C_Args&&... args): m_variant(std::in_place_index<I>, std::forward<C_Args>(args)...)
-        {
+		{}
-        }
 
 		template <std::size_t I, typename U, typename... C_Args>
 		constexpr explicit variant_t(std::in_place_index_t<I>, std::initializer_list<U> il, C_Args&&... args): m_variant(
 			std::in_place_index<I>, il, std::forward<C_Args>(args)...)
-        {
+		{}
-        }
 
 		template <typename T, typename... Args>
 		T& emplace(Args&&... args)
@@ -271,18 +274,14 @@ namespace blt
 		}
 
 		/**
-         * Automatic visitor generation with empty default behavior
+		* Automatic visitor generation
 		* @param visitees user lambdas
 		*/
 		template <typename... Visitee>
-        constexpr auto visit(Visitee&&... visitees) -> decltype(detail::member_func_detail<std::tuple<Visitee...>, std::tuple<Types...>>::make_return_type())
+		constexpr auto visit(
+			Visitee&&... visitees) -> typename detail::member_func_detail<std::tuple<Visitee...>, std::tuple<Types...>>::make_return_type
 		{
-            return std::visit(lambda_visitor{
+			return std::visit(lambda_visitor{std::forward<Visitee>(visitees)...}, m_variant);
-                           std::forward<Visitee>(visitees)...,
-                           [](auto)
-                           {
-                           }
-                       }, m_variant);
 		}
 
 		template <typename Default, typename... Visitee>
@@ -290,46 +289,18 @@ namespace blt
 		{
 			return std::visit(lambda_visitor{
 				std::forward<Visitee>(visitees)...,
-                [default_value=std::forward<Default>(default_value)](auto&& value)
+				[default_value=std::forward<Default>(default_value)](auto&& value) {
-                {
 					return std::forward<decltype(value)>(value);
 				}
 			});
 		}
 
-        template <typename... MemberFuncs>
-        constexpr auto call_member(const MemberFuncs... funcs)
-        {
-            static_assert(std::conjunction_v<std::is_member_function_pointer<std::decay_t<MemberFuncs>>...>,
-                          "Must provide only pointers to member functions!");
-            using meta_t = detail::member_func_detail<std::tuple<MemberFuncs...>, std::tuple<Types...>>;
-            using result_t = decltype(meta_t::make_return_type());
-            return std::visit([=](auto&& value) -> result_t
-            {
-                using ValueType = std::decay_t<decltype(value)>;
-
-                if constexpr (std::disjunction_v<std::is_invocable<std::decay_t<decltype(funcs)>, ValueType>...>)
-                {
-                }
-
-                return *(... || ([&](auto&& func) -> decltype(auto)
-                {
-                    using FuncType = std::decay_t<decltype(func)>;
-                    using ReturnType = std::invoke_result_t<FuncType, ValueType>;
-                    if constexpr (std::is_invocable_v<FuncType, ValueType>)
-                    {
-                        return ((value).*(func))();
-                    }
-                    return std::declval<result_t>();
-                }(cast_member_ptr<std::decay_t<decltype(value)>>(std::forward<decltype(funcs)>(funcs)))));
-            }, m_variant);
-        }
-
 		template <typename MemberFunc, typename... Args>
-        constexpr auto call_member_args(const MemberFunc func, Args&&... args)
+		constexpr auto call_member(const MemberFunc func,
-        {
+									Args&&... args) -> typename detail::member_func_detail<
-            return std::visit([=](auto&& value)
+			std::tuple<MemberFunc>, std::tuple<Types...>>::make_return_type
 		{
+			return std::visit([func,...args=std::forward<Args>(args)](auto&& value) {
 				return ((value).*(func))(std::forward<Args>(args)...);
 			}, m_variant);
 		}
@@ -478,8 +449,7 @@ namespace blt
 	{
 		template <typename>
 		class variant_is_base_of
-        {
+		{};
-        };
 
 		template <typename... Types>
 		class variant_is_base_of<variant_t<Types...>>

libraries/parallel-hashmap

@@ -1 +1 @@
-Subproject commit d88c5e15079047777b418132ece5879e7c9aaa2b
+Subproject commit 93201da2ba5a6aba0a6e57ada64973555629b3e3

tests/variant_tests.cpp

@@ -0,0 +1,135 @@
+/*
+ *  <Short Description>
+ *  Copyright (C) 2025  Brett Terpstra
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+#include <blt/std/variant.h>
+#include <blt/logging/logging.h>
+#include <blt/std/assert.h>
+
+struct base_type
+{
+	[[nodiscard]] virtual int simple() const = 0;
+	[[nodiscard]] virtual std::string to_string() const = 0;
+
+	virtual ~base_type() = default;
+};
+
+struct mutate_type : base_type
+{
+	virtual void mutate(int i) = 0;
+};
+
+struct type1 final : base_type
+{
+	[[nodiscard]] int simple() const override // NOLINT
+	{
+		return 1;
+	}
+
+	[[nodiscard]] std::string to_string() const override // NOLINT
+	{
+		return "Type1";
+	}
+};
+
+
+struct type2 final : base_type
+{
+	[[nodiscard]] int simple() const override // NOLINT
+	{
+		return 2;
+	}
+
+	[[nodiscard]] std::string to_string() const override // NOLINT
+	{
+		return "Type2";
+	}
+};
+
+
+struct type3 final : base_type
+{
+	[[nodiscard]] int simple() const override // NOLINT
+	{
+		return 3;
+	}
+
+	[[nodiscard]] std::string to_string() const override // NOLINT
+	{
+		return "Type3";
+	}
+};
+
+struct storing_type1 final : mutate_type
+{
+	explicit storing_type1(const int i): internal(i)
+	{
+	}
+
+	[[nodiscard]] int simple() const override // NOLINT
+	{
+		return internal;
+	}
+
+	void mutate(const int i) override
+	{
+		internal = i;
+	}
+
+	[[nodiscard]] std::string to_string() const override // NOLINT
+	{
+		return "Storing Type: {" + std::to_string(internal) + "}";
+	}
+
+	int internal;
+};
+
+struct storing_type2 final : mutate_type
+{
+	explicit storing_type2(const float i): internal(i * 2.2534f)
+	{
+	}
+
+	[[nodiscard]] int simple() const override // NOLINT
+	{
+		return static_cast<int>(internal);
+	}
+
+	void mutate(const int i) override
+	{
+		internal = static_cast<float>(i) * 2.2534f;
+	}
+
+	[[nodiscard]] std::string to_string() const override // NOLINT
+	{
+		return "Storing Type: {" + std::to_string(internal) + "}";
+	}
+
+	float internal;
+};
+
+int main()
+{
+
+	blt::variant_t<type1, type2, type3> v1{type1{}};
+	blt::variant_t<type1, type2, type3> v2{type2{}};
+	blt::variant_t<type1, type2, type3> v3{type3{}};
+
+	BLT_TRACE("Variants to_string():");
+	BLT_TRACE("V1: {}", v1.call_member(&base_type::to_string));
+	BLT_TRACE("V2: {}", v2.call_member(&base_type::to_string));
+	BLT_TRACE("V3: {}", v3.call_member(&base_type::to_string));
+}