From add3e12550d03d4408dc4e3169e55c8415e250a9 Mon Sep 17 00:00:00 2001
From: Steven Le Rouzic <steven.lerouzic@gmail.com>
Date: Tue, 20 Aug 2024 10:13:08 +0200
Subject: Rewrite the 4 categories

---
 asl/meta.hpp | 155 ++++++++++++++++++++---------------------------------------
 1 file changed, 51 insertions(+), 104 deletions(-)

(limited to 'asl/meta.hpp')

diff --git a/asl/meta.hpp b/asl/meta.hpp
index 4a5b448..be5fa50 100644
--- a/asl/meta.hpp
+++ b/asl/meta.hpp
@@ -15,6 +15,11 @@ template<typename U, typename V>               struct _select_helper<true, U, V>
 
 template<bool kSelect, typename U, typename V> using select_t = _select_helper<kSelect, U, V>::type;
 
+template<typename U, typename V> struct _is_same_helper       : false_type {};
+template<typename T>             struct _is_same_helper<T, T> : true_type {};
+
+template<typename U, typename V> concept is_same = _is_same_helper<U, V>::value && _is_same_helper<V, U>::value;
+
 template<typename T> auto _as_lref_helper(int) -> id<T&>;
 template<typename T> auto _as_lref_helper(...) -> id<T>;
 
@@ -50,124 +55,66 @@ template<typename T> concept trivially_destructible = __is_trivially_destructibl
 
 using nullptr_t = decltype(nullptr);
 
-template<typename T> struct un_ref      { using type = T; };
-template<typename T> struct un_ref<T&>  { using type = T; };
-template<typename T> struct un_ref<T&&> { using type = T; };
-template<typename T> using  un_ref_t = un_ref<T>::type;
-
-template<typename T> struct un_const          { using type = T; };
-template<typename T> struct un_const<const T> { using type = T; };
-template<typename T> using  un_const_t = un_const<T>::type;
-
-template<typename T> struct un_volatile             { using type = T; };
-template<typename T> struct un_volatile<volatile T> { using type = T; };
-template<typename T> using  un_volatile_t = un_volatile<T>::type;
-
-template<typename T> using un_qual_t = un_const_t<un_volatile_t<T>>;
-
-template<typename T> using un_qualref_t = un_qual_t<un_ref_t<T>>;
-
-template<typename U, typename V> struct _is_same_helper       : false_type {};
-template<typename T>             struct _is_same_helper<T, T> : true_type  {};
-
-template<typename U, typename V>
-concept is_same = _is_same_helper<U, V>::value && _is_same_helper<V, U>::value;
-
-template<typename T> struct _is_const_helper          : false_type {};
-template<typename T> struct _is_const_helper<const T> : true_type  {};
-
-template<typename T> concept is_const = _is_const_helper<T>::value;
+template<typename T> struct _un_const_helper          { using type = T; };
+template<typename T> struct _un_const_helper<const T> { using type = T; };
 
-template<typename T> concept is_void    = is_same<un_qual_t<T>, void>;
-template<typename T> concept is_nullptr = is_same<un_qual_t<T>, nullptr_t>;
+template<typename T> using un_const_t = _un_const_helper<T>::type;
 
-template<typename T> concept is_integral       = __is_integral(T);
-template<typename T> concept is_floating_point = __is_floating_point(T);
-template<typename T> concept is_arithmetic     = is_integral<T> || is_floating_point<T>;
+template<typename T> struct _un_volatile_helper             { using type = T; };
+template<typename T> struct _un_volatile_helper<volatile T> { using type = T; };
 
-template<typename T>            struct _is_array_helper       : false_type {};
-template<typename T>            struct _is_array_helper<T[]>  : true_type  {};
-template<typename T, int N> struct _is_array_helper<T[N]> : true_type  {};
+template<typename T> using un_volatile_t = _un_volatile_helper<T>::type;
 
-template<typename T> concept is_array = _is_array_helper<T>::value;
+template<typename T> using un_cv_t = un_volatile_t<un_const_t<T>>;
 
-template<typename T> concept is_class = __is_class(T);
-template<typename T> concept is_union = __is_union(T);
+template<typename T> concept is_void = is_same<void, un_cv_t<T>>;
 
-template<typename T> concept is_enum  = __is_enum(T);
+template<typename T> struct _is_ref_helper      { static constexpr bool l = false; static constexpr bool r = false; };
+template<typename T> struct _is_ref_helper<T&>  { static constexpr bool l = true;  static constexpr bool r = false; };
+template<typename T> struct _is_ref_helper<T&&> { static constexpr bool l = false; static constexpr bool r = true;  };
 
-template<typename T> struct _is_ptr_helper     : false_type {};
-template<typename T> struct _is_ptr_helper<T*> : true_type  {};
+template<typename T> concept is_ref = _is_ref_helper<T>::l || _is_ref_helper<T>::r;
 
-template<typename T> concept is_ptr = _is_ptr_helper<un_qual_t<T>>::value;
+template<typename T> struct _tame_helper { using type = T; };
 
-template<typename T> struct _is_ref_helper      { static constexpr bool lref = false; static constexpr bool rref = false; };
-template<typename T> struct _is_ref_helper<T&>  { static constexpr bool lref = true;  static constexpr bool rref = false; };
-template<typename T> struct _is_ref_helper<T&&> { static constexpr bool lref = false; static constexpr bool rref = true;  };
+#define TAME_HELPER_IMPL(TRAILING)                                  \
+    template<typename R, typename... Args>                          \
+    struct _tame_helper<R(Args...) TRAILING> { using type = R(Args...); }
 
-template<typename T> concept is_lref = _is_ref_helper<T>::lref;
-template<typename T> concept is_rref = _is_ref_helper<T>::rref;
-template<typename T> concept is_ref  = is_lref<T> || is_rref<T>;
+TAME_HELPER_IMPL();
+TAME_HELPER_IMPL(&);
+TAME_HELPER_IMPL(&&);
+TAME_HELPER_IMPL(const);
+TAME_HELPER_IMPL(const &);
+TAME_HELPER_IMPL(const &&);
+TAME_HELPER_IMPL(volatile);
+TAME_HELPER_IMPL(volatile &);
+TAME_HELPER_IMPL(volatile &&);
+TAME_HELPER_IMPL(const volatile);
+TAME_HELPER_IMPL(const volatile &);
+TAME_HELPER_IMPL(const volatile &&);
+TAME_HELPER_IMPL(noexcept);
+TAME_HELPER_IMPL(& noexcept);
+TAME_HELPER_IMPL(&& noexcept);
+TAME_HELPER_IMPL(const noexcept);
+TAME_HELPER_IMPL(const & noexcept);
+TAME_HELPER_IMPL(const && noexcept);
+TAME_HELPER_IMPL(volatile noexcept);
+TAME_HELPER_IMPL(volatile & noexcept);
+TAME_HELPER_IMPL(volatile && noexcept);
+TAME_HELPER_IMPL(const volatile noexcept);
+TAME_HELPER_IMPL(const volatile & noexcept);
+TAME_HELPER_IMPL(const volatile && noexcept);
 
-template<typename T> concept is_func = !is_const<const T> && !is_ref<T>;
-
-template<typename T>             struct _is_member_ptr_helper         : false_type {};
-template<typename T, typename U> struct _is_member_ptr_helper<T U::*> : true_type  {};
-
-template<typename T>             struct _is_member_func_ptr_helper         : false_type {};
-template<typename T, typename U> struct _is_member_func_ptr_helper<T U::*> : bool_constant<is_func<T>>  {};
-
-template<typename T> concept is_member_ptr        = _is_member_ptr_helper<un_qual_t<T>>::value;
-template<typename T> concept is_member_func_ptr   = _is_member_func_ptr_helper<un_qual_t<T>>::value;
-template<typename T> concept is_member_object_ptr = is_member_ptr<T> && !is_member_func_ptr<T>;
-
-template<typename T> concept is_fundamental = is_arithmetic<T> || is_void<T> || is_nullptr<T>;
-template<typename T> concept is_compound    = !is_fundamental<T>;
-template<typename T> concept is_scalar      = (is_fundamental<T> && !is_void<T>) || is_enum<T> || is_ptr<T> || is_member_ptr<T>;
-template<typename T> concept is_object      = is_scalar<T> || is_class<T> || is_union<T>;
-
-template<typename T> concept is_empty = is_void<T> || __is_empty(T);
-
-struct empty {};
-
-template<typename T> using devoid_t = select_t<is_void<T>, empty, T>;
-
-template<typename F> struct _tame_helper { using type = F; };
-
-#define ASL_TAME_IMPL(SUFFIX) \
-    template<typename Ret, typename... Args> \
-    struct _tame_helper<Ret(Args...) SUFFIX> { using type = Ret(Args...); }
-
-ASL_TAME_IMPL();
-ASL_TAME_IMPL(const);
-ASL_TAME_IMPL(volatile);
-ASL_TAME_IMPL(volatile const);
-ASL_TAME_IMPL(&&);
-ASL_TAME_IMPL(const &&);
-ASL_TAME_IMPL(volatile &&);
-ASL_TAME_IMPL(volatile const &&);
-ASL_TAME_IMPL(&);
-ASL_TAME_IMPL(const &);
-ASL_TAME_IMPL(volatile &);
-ASL_TAME_IMPL(volatile const &);
-ASL_TAME_IMPL(noexcept);
-ASL_TAME_IMPL(const noexcept);
-ASL_TAME_IMPL(volatile noexcept);
-ASL_TAME_IMPL(volatile const noexcept);
-ASL_TAME_IMPL(&& noexcept);
-ASL_TAME_IMPL(const && noexcept);
-ASL_TAME_IMPL(volatile && noexcept);
-ASL_TAME_IMPL(volatile const && noexcept);
-ASL_TAME_IMPL(& noexcept);
-ASL_TAME_IMPL(const & noexcept);
-ASL_TAME_IMPL(volatile & noexcept);
-ASL_TAME_IMPL(volatile const & noexcept);
-
-#undef ASL_TAME_IMPL
+#undef TAME_HELPER_IMPL
 
 template<typename T> using tame_t = _tame_helper<T>::type;
 
-template<typename T> using as_raw_ptr_t = un_ref_t<tame_t<T>>*;
+template<typename T>                   struct _is_func_helper             : false_type {};
+template<typename R, typename... Args> struct _is_func_helper<R(Args...)> : true_type {};
+
+template<typename T> concept is_func = _is_func_helper<tame_t<T>>::value;
 
+template<typename T> concept is_object = !is_void<T> && !is_ref<T> && !is_func<T>;
 
 } // namespace asl
-- 
cgit