From 659c168a14347aa8c718dfd472008effed4c90b5 Mon Sep 17 00:00:00 2001
From: HJfod <60038575+HJfod@users.noreply.github.com>
Date: Sat, 31 Aug 2024 21:35:41 +0300
Subject: [PATCH] add generic function helpers

---
 loader/include/Geode/utils/function.hpp | 59 +++++++++++++++++++++++++
 1 file changed, 59 insertions(+)
 create mode 100644 loader/include/Geode/utils/function.hpp

diff --git a/loader/include/Geode/utils/function.hpp b/loader/include/Geode/utils/function.hpp
new file mode 100644
index 00000000..855f1951
--- /dev/null
+++ b/loader/include/Geode/utils/function.hpp
@@ -0,0 +1,59 @@
+#pragma once
+
+#include <tuple>
+
+namespace geode::utils::function {
+    namespace detail {
+        template <class F>
+        struct ImplExtract;
+
+        template <class R, class... A>
+        struct ImplExtract<R(A...)> {
+            using Type = R(A...);
+            using Return = R;
+            using Args = std::tuple<A...>;
+            static constexpr std::size_t ARG_COUNT = std::tuple_size_v<Args>;
+        };
+        template <class R, class... A>
+        struct ImplExtract<R(*)(A...)> {
+            using Type = R(A...);
+            using Return = R;
+            using Args = std::tuple<A...>;
+            static constexpr std::size_t ARG_COUNT = std::tuple_size_v<Args>;
+        };
+        template <class R, class C, class... A>
+        struct ImplExtract<R(C::*)(A...)> {
+            using Type = R(A...);
+            using Class = C;
+            using Return = R;
+            using Args = std::tuple<A...>;
+            static constexpr std::size_t ARG_COUNT = std::tuple_size_v<Args>;
+        };
+        template <class R, class C, class... A>
+        struct ImplExtract<R(C::*)(A...) const> {
+            using Type = R(A...);
+            using Class = C;
+            using Return = R;
+            using Args = std::tuple<A...>;
+            static constexpr std::size_t ARG_COUNT = std::tuple_size_v<Args>;
+        };
+        template <class F>
+            requires requires { &F::operator(); }
+        struct ImplExtract<F> : public ImplExtract<decltype(&F::operator())> {};
+
+        template <class F>
+        using Extract = ImplExtract<std::remove_cvref_t<F>>;
+    }
+
+    template <class F>
+    using FunctionInfo = detail::Extract<F>;
+
+    template <class F>
+    using Return = typename detail::Extract<F>::Return;
+
+    template <class F>
+    using Args = typename detail::Extract<F>::Args;
+
+    template <std::size_t Ix, class F>
+    using Arg = std::tuple_element_t<Ix, typename detail::Extract<F>::Args>;
+}