From 3150e07f6bf53fbb360ae3c85a6935aa7b1d3fa5 Mon Sep 17 00:00:00 2001
From: _Redstone_c_ <myredstone1024@gmail.com>
Date: Wed, 23 Mar 2022 17:50:55 +0800
Subject: [PATCH] feat(templates): add TIntegerSequence and the corresponding
 testing

---
 .../Source/Public/Templates/IntegerSequence.h | 66 +++++++++++++++++++
 .../Source/Public/Templates/Templates.h       |  1 +
 2 files changed, 67 insertions(+)
 create mode 100644 Redcraft.Utility/Source/Public/Templates/IntegerSequence.h

diff --git a/Redcraft.Utility/Source/Public/Templates/IntegerSequence.h b/Redcraft.Utility/Source/Public/Templates/IntegerSequence.h
new file mode 100644
index 0000000..84a2706
--- /dev/null
+++ b/Redcraft.Utility/Source/Public/Templates/IntegerSequence.h
@@ -0,0 +1,66 @@
+#pragma once
+
+#include "CoreTypes.h"
+
+NAMESPACE_REDCRAFT_BEGIN
+NAMESPACE_MODULE_BEGIN(Redcraft)
+NAMESPACE_MODULE_BEGIN(Utility)
+
+template <typename T, T... Ints>
+struct TIntegerSequence 
+{
+	using ValueType = T;
+	static constexpr size_t Size() { return sizeof...(Ints); }
+};
+
+NAMESPACE_PRIVATE_BEGIN
+
+#ifdef _MSC_VER
+
+template <unsigned N, typename T>
+struct TMakeIntegerSequence
+{
+	using Type = typename __make_integer_seq<TIntegerSequence, T, N>;
+};
+
+#elif __has_builtin(__make_integer_seq)
+
+template <unsigned N, typename T>
+struct TMakeIntegerSequence
+{
+	using Type = typename __make_integer_seq<TIntegerSequence, T, N>;
+};
+
+#else
+
+template <unsigned N, typename T, T... Ints>
+struct TMakeIntegerSequence
+{
+	using Type = typename TMakeIntegerSequence<N - 1, T, T(N - 1), Ints...>::Type;
+};
+
+template <typename T, T... Ints>
+struct TMakeIntegerSequence<0, T, Ints...>
+{
+	using Type = TIntegerSequence<T, Ints...>;
+};
+
+#endif
+
+NAMESPACE_PRIVATE_END
+
+template <size_t... Ints>
+using TIndexSequence = TIntegerSequence<size_t, Ints...>;
+
+template<typename T, T N>
+using TMakeIntegerSequence = typename NAMESPACE_PRIVATE::TMakeIntegerSequence<N, T>::Type;
+
+template<size_t N>
+using TMakeIndexSequence = TMakeIntegerSequence<size_t, N>;
+
+template<typename... T>
+using TIndexSequenceFor = TMakeIndexSequence<sizeof...(T)>;
+
+NAMESPACE_MODULE_END(Utility)
+NAMESPACE_MODULE_END(Redcraft)
+NAMESPACE_REDCRAFT_END
diff --git a/Redcraft.Utility/Source/Public/Templates/Templates.h b/Redcraft.Utility/Source/Public/Templates/Templates.h
index 5024671..d18d47c 100644
--- a/Redcraft.Utility/Source/Public/Templates/Templates.h
+++ b/Redcraft.Utility/Source/Public/Templates/Templates.h
@@ -9,3 +9,4 @@
 #include "Templates/Optional.h"
 #include "Templates/Variant.h"
 #include "Templates/Any.h"
+#include "Templates/IntegerSequence.h"