From 3131130c4c254173f5511a0803d358551656e7d3 Mon Sep 17 00:00:00 2001
From: jyxiong <jingyu.xiong@foxmail.com>
Date: Tue, 23 Sep 2025 23:27:01 +0800
Subject: [PATCH] feat: impl new type traits

---
 source/tinystl/experimental/type_traits.h     | 62 +++++++++++++++++++
 source/tinystl/type_traits.h                  |  3 +
 source/tinystl/type_traits/add_reference.h    | 35 +++++++++++
 source/tinystl/type_traits/is_constructible.h | 38 ++++++++++++
 source/tinystl/type_traits/is_convertible.h   | 21 +++++++
 source/tinystl/type_traits/is_empty.h         |  2 +-
 source/tinystl/type_traits/is_enum.h          |  2 +-
 7 files changed, 161 insertions(+), 2 deletions(-)
 create mode 100644 source/tinystl/experimental/type_traits.h
 create mode 100644 source/tinystl/type_traits/add_reference.h
 create mode 100644 source/tinystl/type_traits/is_constructible.h
 create mode 100644 source/tinystl/type_traits/is_convertible.h

diff --git a/source/tinystl/experimental/type_traits.h b/source/tinystl/experimental/type_traits.h
new file mode 100644
index 0000000..3c0c119
--- /dev/null
+++ b/source/tinystl/experimental/type_traits.h
@@ -0,0 +1,62 @@
+#pragma once
+
+#include "tinystl/type_traits/integral_constant.h"
+#include "tinystl/type_traits/void_t.h"
+#include "tinystl/type_traits/is_same.h"
+#include "tinystl/type_traits/is_convertible.h"
+
+namespace detail {
+template <
+  class Default, class AlwaysVoid, template <class...> class Op, class... Args>
+struct detector {
+  using value_t = tinystl::false_type;
+  using type = Default;
+};
+
+template <class Default, template <class...> class Op, class... Args>
+struct detector<Default, tinystl::void_t<Op<Args...>>, Op, Args...> {
+  using value_t = tinystl::true_type;
+  using type = Op<Args...>;
+};
+} // namespace detail
+
+namespace tinystl {
+
+struct nonesuch {
+  ~nonesuch() = delete;
+  nonesuch(nonesuch const &) = delete;
+  void operator=(nonesuch const &) = delete;
+};
+
+template <template <class...> class Op, class... Args>
+using is_detected =
+  typename detail::detector<nonesuch, void, Op, Args...>::value_t;
+
+template <template <class...> class Op, class... Args>
+using detected_t = typename detail::detector<nonesuch, void, Op, Args...>::type;
+
+template <class Default, template <class...> class Op, class... Args>
+using detected_or = detail::detector<Default, void, Op, Args...>;
+
+template< template<class...> class Op, class... Args >
+constexpr inline bool is_detected_v = is_detected<Op, Args...>::value;
+
+template< class Default, template<class...> class Op, class... Args >
+using detected_or_t = typename detected_or<Default, Op, Args...>::type;
+
+template< class Expected, template<class...> class Op, class... Args >
+using is_detected_exact = is_same<Expected, detected_t<Op, Args...>>;
+
+template< class Expected, template<class...> class Op, class... Args >
+constexpr inline bool is_detected_exact_v =
+    is_detected_exact<Expected, Op, Args...>::value;
+
+template< class To, template<class...> class Op, class... Args >
+using is_detected_convertible =
+    is_convertible<detected_t<Op, Args...>, To>;
+
+template< class To, template<class...> class Op, class... Args >
+constexpr inline bool is_detected_convertible_v =
+    is_detected_convertible<To, Op, Args...>::value;
+
+} // namespace tinystl
\ No newline at end of file
diff --git a/source/tinystl/type_traits.h b/source/tinystl/type_traits.h
index c16ee84..3aa11b8 100644
--- a/source/tinystl/type_traits.h
+++ b/source/tinystl/type_traits.h
@@ -1,6 +1,9 @@
 #pragma once
 
 // https://en.cppreference.com/w/cpp/header/type_traits.html
+// https://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html
+// https://clang.llvm.org/docs/LanguageExtensions.html#type-trait-primitives
+// https://learn.microsoft.com/en-us/cpp/extensions/compiler-support-for-type-traits-cpp-component-extensions?view=msvc-170
 
 // composite_type_categories
 #include <tinystl/type_traits/is_arithmetic.h>
diff --git a/source/tinystl/type_traits/add_reference.h b/source/tinystl/type_traits/add_reference.h
new file mode 100644
index 0000000..bafba02
--- /dev/null
+++ b/source/tinystl/type_traits/add_reference.h
@@ -0,0 +1,35 @@
+#pragma once
+
+#include "tinystl/type_traits/void_t.h"
+
+namespace tinystl {
+
+template <class _Ty, class = void>
+struct _Add_reference { // add reference (non-referenceable type)
+    using _Lvalue = _Ty;
+    using _Rvalue = _Ty;
+};
+
+template <class _Ty>
+struct _Add_reference<_Ty, void_t<_Ty&>> { // (referenceable type)
+    using _Lvalue = _Ty&;
+    using _Rvalue = _Ty&&;
+};
+
+template <class _Ty>
+struct add_lvalue_reference {
+    using type = typename _Add_reference<_Ty>::_Lvalue;
+};
+
+template <class _Ty>
+using add_lvalue_reference_t = typename _Add_reference<_Ty>::_Lvalue;
+
+template <class _Ty>
+struct add_rvalue_reference {
+    using type = typename _Add_reference<_Ty>::_Rvalue;
+};
+
+template <class _Ty>
+using add_rvalue_reference_t = typename _Add_reference<_Ty>::_Rvalue;
+
+} // namespace tinystl
\ No newline at end of file
diff --git a/source/tinystl/type_traits/is_constructible.h b/source/tinystl/type_traits/is_constructible.h
new file mode 100644
index 0000000..245b167
--- /dev/null
+++ b/source/tinystl/type_traits/is_constructible.h
@@ -0,0 +1,38 @@
+#pragma once
+
+#include "tinystl/type_traits/add_reference.h"
+#include "tinystl/type_traits/integral_constant.h"
+
+
+namespace tinystl {
+
+template <class _Tp, class... _Args>
+struct is_constructible : bool_constant<__is_constructible(_Tp, _Args...)> {};
+
+template <class _Tp, class... _Args>
+inline constexpr bool is_constructible_v = __is_constructible(_Tp, _Args...);
+
+template <class _Tp>
+struct is_copy_constructible
+  : bool_constant<__is_constructible(_Tp, add_lvalue_reference_t<const _Tp>)> {
+};
+
+template <class _Tp>
+inline constexpr bool is_copy_constructible_v =
+  is_copy_constructible<_Tp>::value;
+
+template <class _Tp>
+struct is_move_constructible
+  : bool_constant<__is_constructible(_Tp, add_rvalue_reference_t<_Tp>)> {};
+
+template <class _Tp>
+inline constexpr bool is_move_constructible_v =
+  is_move_constructible<_Tp>::value;
+
+template <class _Tp>
+struct is_default_constructible : bool_constant<__is_constructible(_Tp)> {};
+
+template <class _Tp>
+inline constexpr bool is_default_constructible_v = __is_constructible(_Tp);
+
+} // namespace tinystl
\ No newline at end of file
diff --git a/source/tinystl/type_traits/is_convertible.h b/source/tinystl/type_traits/is_convertible.h
new file mode 100644
index 0000000..8ffaa02
--- /dev/null
+++ b/source/tinystl/type_traits/is_convertible.h
@@ -0,0 +1,21 @@
+#pragma once
+
+#include "tinystl/type_traits/integral_constant.h"
+
+namespace tinystl {
+
+template <class _T1, class _T2>
+struct is_convertible : bool_constant<__is_convertible(_T1, _T2)> {};
+
+template <class _From, class _To>
+inline constexpr bool is_convertible_v = __is_convertible(_From, _To);
+
+template <class _Tp, class _Up>
+struct is_nothrow_convertible
+  : bool_constant<__is_nothrow_convertible(_Tp, _Up)> {};
+
+template <class _Tp, class _Up>
+inline constexpr bool is_nothrow_convertible_v =
+  __is_nothrow_convertible(_Tp, _Up);
+
+} // namespace tinystl
\ No newline at end of file
diff --git a/source/tinystl/type_traits/is_empty.h b/source/tinystl/type_traits/is_empty.h
index 0879888..2e37a72 100644
--- a/source/tinystl/type_traits/is_empty.h
+++ b/source/tinystl/type_traits/is_empty.h
@@ -7,5 +7,5 @@ template <class T>
 struct is_empty : bool_constant<__is_empty(T)> {};
 
 template <class T>
-inline constexpr bool is_empty_v = is_empty<T>::value;
+inline constexpr bool is_empty_v = __is_empty(T);
 } // namespace tinystl
diff --git a/source/tinystl/type_traits/is_enum.h b/source/tinystl/type_traits/is_enum.h
index 5438742..0e0f442 100644
--- a/source/tinystl/type_traits/is_enum.h
+++ b/source/tinystl/type_traits/is_enum.h
@@ -8,6 +8,6 @@ template <class T>
 struct is_enum : tinystl::bool_constant<__is_enum(T)> {};
 
 template <class T>
-inline constexpr bool is_enum_v = is_enum<T>::value;
+inline constexpr bool is_enum_v = __is_enum(T);
 
 } // namespace tinystl