From 7d51b1f79220532a02028d1185a328de11b66cb2 Mon Sep 17 00:00:00 2001
From: Mingxin Wang <mingxwa@microsoft.com>
Date: Fri, 15 Nov 2024 15:18:08 +0800
Subject: [PATCH 1/5] test

---
 proxy.h | 44 +++++++++++++++++++++++++++++++-------------
 1 file changed, 31 insertions(+), 13 deletions(-)

diff --git a/proxy.h b/proxy.h
index 16ef19c..c7a778b 100644
--- a/proxy.h
+++ b/proxy.h
@@ -460,20 +460,25 @@ class ___PRO_ENFORCE_EBO composite_accessor_impl : public As... {
       = default;
 };
 
+template <class T>
+struct accessor_traits_impl : std::type_identity<void> {};
+template <class T>
+    requires(std::is_nothrow_default_constructible_v<T> &&
+        std::is_trivially_copyable_v<T> && !std::is_final_v<T>)
+struct accessor_traits_impl<T> : std::type_identity<T> {};
 template <class SFINAE, class T, class... Args>
 struct sfinae_accessor_traits : std::type_identity<void> {};
 template <class T, class... Args>
 struct sfinae_accessor_traits<
     std::void_t<typename T::template accessor<Args...>>, T, Args...>
-    : std::type_identity<typename T::template accessor<Args...>> {};
+    : accessor_traits_impl<typename T::template accessor<Args...>> {};
 template <class T, class... Args>
 using accessor_t = typename sfinae_accessor_traits<void, T, Args...>::type;
 
 template <bool IS_DIRECT, class F, class O, class I>
 struct composite_accessor_reduction : std::type_identity<O> {};
 template <bool IS_DIRECT, class F, class... As, class I>
-    requires(IS_DIRECT == I::is_direct && std::is_trivial_v<accessor_t<I, F>> &&
-        !std::is_final_v<accessor_t<I, F>>)
+    requires(IS_DIRECT == I::is_direct && !std::is_void_v<accessor_t<I, F>>)
 struct composite_accessor_reduction<
     IS_DIRECT, F, composite_accessor_impl<As...>, I>
     { using type = composite_accessor_impl<As..., accessor_t<I, F>>; };
@@ -678,8 +683,17 @@ class proxy : public details::facade_traits<F>::base {
   using _Traits = details::facade_traits<F>;
 
  public:
-  proxy() noexcept = default;
-  proxy(std::nullptr_t) noexcept {}
+  proxy() noexcept {
+    if constexpr (_Traits::has_indirection) {
+      std::ignore = **this;
+      std::ignore = *std::as_const(*this);
+      std::ignore = (*this).operator->();
+      std::ignore = (std::move(*this)).operator->();
+      std::ignore = (std::as_const(*this)).operator->();
+      std::ignore = (std::forward<const proxy&&>(*this)).operator->();
+    }
+  }
+  proxy(std::nullptr_t) noexcept : proxy() {}
   proxy(const proxy&) noexcept requires(F::constraints.copyability ==
       constraint_level::trivial) = default;
   proxy(const proxy& rhs)
@@ -709,12 +723,12 @@ class proxy : public details::facade_traits<F>::base {
   template <class P>
   proxy(P&& ptr) noexcept(std::is_nothrow_constructible_v<std::decay_t<P>, P>)
       requires(proxiable<std::decay_t<P>, F> &&
-          std::is_constructible_v<std::decay_t<P>, P>)
+          std::is_constructible_v<std::decay_t<P>, P>) : proxy()
       { initialize<std::decay_t<P>>(std::forward<P>(ptr)); }
   template <proxiable<F> P, class... Args>
   explicit proxy(std::in_place_type_t<P>, Args&&... args)
       noexcept(std::is_nothrow_constructible_v<P, Args...>)
-      requires(std::is_constructible_v<P, Args...>)
+      requires(std::is_constructible_v<P, Args...>) : proxy()
       { initialize<P>(std::forward<Args>(args)...); }
   template <proxiable<F> P, class U, class... Args>
   explicit proxy(std::in_place_type_t<P>, std::initializer_list<U> il,
@@ -722,7 +736,7 @@ class proxy : public details::facade_traits<F>::base {
       noexcept(std::is_nothrow_constructible_v<
           P, std::initializer_list<U>&, Args...>)
       requires(std::is_constructible_v<P, std::initializer_list<U>&, Args...>)
-      { initialize<P>(il, std::forward<Args>(args)...); }
+      : proxy() { initialize<P>(il, std::forward<Args>(args)...); }
   proxy& operator=(std::nullptr_t)
       noexcept(F::constraints.destructibility >= constraint_level::nothrow)
       requires(F::constraints.destructibility >= constraint_level::nontrivial)
@@ -1106,10 +1120,9 @@ proxy<F> make_proxy(T&& value) {
     template <class __F, class __C, class... __Os> \
     struct ___PRO_ENFORCE_EBO accessor { accessor() = delete; }; \
     template <class __F, class __C, class... __Os> \
-        requires(sizeof...(__Os) > 1u && \
-            (::std::is_trivial_v<accessor<__F, __C, __Os>> && ...)) \
+        requires(sizeof...(__Os) > 1u) \
     struct accessor<__F, __C, __Os...> : accessor<__F, __C, __Os>... \
-        { using accessor<__F, __C, __Os>:: __VA_ARGS__ ...; }; \
+        { using accessor<__F, __C, __Os>::__VA_ARGS__...; }; \
     __MACRO(, *this, __VA_ARGS__); \
     __MACRO(noexcept, *this, __VA_ARGS__); \
     __MACRO(&, *this, __VA_ARGS__); \
@@ -1128,8 +1141,7 @@ proxy<F> make_proxy(T&& value) {
     template <class __F, class __C, class... __Os> \
     struct ___PRO_ENFORCE_EBO accessor { accessor() = delete; }; \
     template <class __F, class __C, class... __Os> \
-        requires(sizeof...(__Os) > 1u && \
-            (::std::is_trivial_v<accessor<__F, __C, __Os>> && ...)) \
+        requires(sizeof...(__Os) > 1u) \
     struct accessor<__F, __C, __Os...> : accessor<__F, __C, __Os>... {}; \
     __MACRO(,, accessor& __self, __self, __VA_ARGS__); \
     __MACRO(noexcept, noexcept, accessor& __self, __self, __VA_ARGS__); \
@@ -1227,6 +1239,7 @@ struct facade_impl {
 #define ___PRO_DEF_UPWARD_CONVERSION_ACCESSOR(Q, SELF, ...) \
     template <class F2, class C> \
     struct accessor<F2, C, proxy<F>() Q> { \
+      accessor() noexcept { std::ignore = &accessor::__VA_ARGS__; } \
       __VA_ARGS__ () Q { \
         if (access_proxy<F2>(SELF).has_value()) { \
           return proxy_invoke<C, proxy<F>() Q>(access_proxy<F2>(SELF)); \
@@ -1389,12 +1402,14 @@ struct operator_dispatch;
 #define ___PRO_DEF_LHS_LEFT_OP_ACCESSOR(Q, SELF, ...) \
     template <class F, class C, class R> \
     struct accessor<F, C, R() Q> { \
+      accessor() noexcept { std::ignore = &accessor::__VA_ARGS__; } \
       R __VA_ARGS__ () Q \
           { return proxy_invoke<C, R() Q>(access_proxy<F>(SELF)); } \
     }
 #define ___PRO_DEF_LHS_ANY_OP_ACCESSOR(Q, SELF, ...) \
     template <class F, class C, class R, class... Args> \
     struct accessor<F, C, R(Args...) Q> { \
+      accessor() noexcept { std::ignore = &accessor::__VA_ARGS__; } \
       R __VA_ARGS__ (Args... args) Q { \
         return proxy_invoke<C, R(Args...) Q>( \
             access_proxy<F>(SELF), std::forward<Args>(args)...); \
@@ -1460,6 +1475,7 @@ struct operator_dispatch;
 #define ___PRO_DEF_LHS_ASSIGNMENT_OP_ACCESSOR(Q, SELF, ...) \
     template <class F, class C, class R, class Arg> \
     struct accessor<F, C, R(Arg) Q> { \
+      accessor() noexcept { std::ignore = &accessor::__VA_ARGS__; } \
       decltype(auto) __VA_ARGS__ (Arg arg) Q { \
         proxy_invoke<C, R(Arg) Q>( \
             access_proxy<F>(SELF), std::forward<Arg>(arg)); \
@@ -1577,6 +1593,7 @@ struct operator_dispatch<"[]", false> {
 #define ___PRO_DEF_CONVERSION_ACCESSOR(Q, SELF, ...) \
     template <class F, class C> \
     struct accessor<F, C, T() Q> { \
+      accessor() noexcept { std::ignore = &accessor::__VA_ARGS__; } \
       explicit(Expl) __VA_ARGS__ () Q \
           { return proxy_invoke<C, T() Q>(access_proxy<F>(SELF)); } \
     }
@@ -1604,6 +1621,7 @@ struct conversion_dispatch {
 #define ___PRO_DEF_MEM_ACCESSOR(__Q, __SELF, ...) \
     template <class __F, class __C, class __R, class... __Args> \
     struct accessor<__F, __C, __R(__Args...) __Q> { \
+      accessor() noexcept { ::std::ignore = &accessor::__VA_ARGS__; } \
       __R __VA_ARGS__ (__Args... __args) __Q { \
         return ::pro::proxy_invoke<__C, __R(__Args...) __Q>( \
             ::pro::access_proxy<__F>(__SELF), \

From cd306186b17f656ac1205923e46314b823b77878 Mon Sep 17 00:00:00 2001
From: Mingxin Wang <mingxwa@microsoft.com>
Date: Fri, 15 Nov 2024 17:31:17 +0800
Subject: [PATCH 2/5] test

---
 proxy.h | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/proxy.h b/proxy.h
index c7a778b..c5d6f17 100644
--- a/proxy.h
+++ b/proxy.h
@@ -683,6 +683,9 @@ class proxy : public details::facade_traits<F>::base {
   using _Traits = details::facade_traits<F>;
 
  public:
+#ifdef NODEBUG
+  proxy() noexcept = default;
+#else
   proxy() noexcept {
     if constexpr (_Traits::has_indirection) {
       std::ignore = **this;
@@ -693,6 +696,7 @@ class proxy : public details::facade_traits<F>::base {
       std::ignore = (std::forward<const proxy&&>(*this)).operator->();
     }
   }
+#endif  // NODEBUG
   proxy(std::nullptr_t) noexcept : proxy() {}
   proxy(const proxy&) noexcept requires(F::constraints.copyability ==
       constraint_level::trivial) = default;
@@ -1162,6 +1166,13 @@ proxy<F> make_proxy(T&& value) {
     __MACRO(const&& noexcept, noexcept, const accessor&& __self, \
         ::std::forward<const accessor>(__self), __VA_ARGS__);
 
+#ifdef NODEBUG
+#define ___PRO_DEF_MEM_ACCESSOR_CTOR(...)
+#else
+#define ___PRO_DEF_MEM_ACCESSOR_CTOR(...) \
+    accessor() noexcept { ::std::ignore = &accessor::__VA_ARGS__; }
+#endif  // NODEBUG
+
 namespace details {
 
 constexpr std::size_t invalid_size = std::numeric_limits<std::size_t>::max();
@@ -1239,7 +1250,7 @@ struct facade_impl {
 #define ___PRO_DEF_UPWARD_CONVERSION_ACCESSOR(Q, SELF, ...) \
     template <class F2, class C> \
     struct accessor<F2, C, proxy<F>() Q> { \
-      accessor() noexcept { std::ignore = &accessor::__VA_ARGS__; } \
+      ___PRO_DEF_MEM_ACCESSOR_CTOR(__VA_ARGS__) \
       __VA_ARGS__ () Q { \
         if (access_proxy<F2>(SELF).has_value()) { \
           return proxy_invoke<C, proxy<F>() Q>(access_proxy<F2>(SELF)); \
@@ -1402,14 +1413,14 @@ struct operator_dispatch;
 #define ___PRO_DEF_LHS_LEFT_OP_ACCESSOR(Q, SELF, ...) \
     template <class F, class C, class R> \
     struct accessor<F, C, R() Q> { \
-      accessor() noexcept { std::ignore = &accessor::__VA_ARGS__; } \
+      ___PRO_DEF_MEM_ACCESSOR_CTOR(__VA_ARGS__) \
       R __VA_ARGS__ () Q \
           { return proxy_invoke<C, R() Q>(access_proxy<F>(SELF)); } \
     }
 #define ___PRO_DEF_LHS_ANY_OP_ACCESSOR(Q, SELF, ...) \
     template <class F, class C, class R, class... Args> \
     struct accessor<F, C, R(Args...) Q> { \
-      accessor() noexcept { std::ignore = &accessor::__VA_ARGS__; } \
+      ___PRO_DEF_MEM_ACCESSOR_CTOR(__VA_ARGS__) \
       R __VA_ARGS__ (Args... args) Q { \
         return proxy_invoke<C, R(Args...) Q>( \
             access_proxy<F>(SELF), std::forward<Args>(args)...); \
@@ -1475,7 +1486,7 @@ struct operator_dispatch;
 #define ___PRO_DEF_LHS_ASSIGNMENT_OP_ACCESSOR(Q, SELF, ...) \
     template <class F, class C, class R, class Arg> \
     struct accessor<F, C, R(Arg) Q> { \
-      accessor() noexcept { std::ignore = &accessor::__VA_ARGS__; } \
+      ___PRO_DEF_MEM_ACCESSOR_CTOR(__VA_ARGS__) \
       decltype(auto) __VA_ARGS__ (Arg arg) Q { \
         proxy_invoke<C, R(Arg) Q>( \
             access_proxy<F>(SELF), std::forward<Arg>(arg)); \
@@ -1593,7 +1604,7 @@ struct operator_dispatch<"[]", false> {
 #define ___PRO_DEF_CONVERSION_ACCESSOR(Q, SELF, ...) \
     template <class F, class C> \
     struct accessor<F, C, T() Q> { \
-      accessor() noexcept { std::ignore = &accessor::__VA_ARGS__; } \
+      ___PRO_DEF_MEM_ACCESSOR_CTOR(__VA_ARGS__) \
       explicit(Expl) __VA_ARGS__ () Q \
           { return proxy_invoke<C, T() Q>(access_proxy<F>(SELF)); } \
     }
@@ -1621,7 +1632,7 @@ struct conversion_dispatch {
 #define ___PRO_DEF_MEM_ACCESSOR(__Q, __SELF, ...) \
     template <class __F, class __C, class __R, class... __Args> \
     struct accessor<__F, __C, __R(__Args...) __Q> { \
-      accessor() noexcept { ::std::ignore = &accessor::__VA_ARGS__; } \
+      ___PRO_DEF_MEM_ACCESSOR_CTOR(__VA_ARGS__) \
       __R __VA_ARGS__ (__Args... __args) __Q { \
         return ::pro::proxy_invoke<__C, __R(__Args...) __Q>( \
             ::pro::access_proxy<__F>(__SELF), \

From 56beecda273736e89f9370c39b17e5bb6981e5d7 Mon Sep 17 00:00:00 2001
From: Mingxin Wang <mingxwa@microsoft.com>
Date: Mon, 18 Nov 2024 19:38:14 +0800
Subject: [PATCH 3/5] Generate symbols for member accessors

---
 docs/ProAccessible.md |  2 +-
 proxy.h               | 30 ++++++++++++++++--------------
 2 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/docs/ProAccessible.md b/docs/ProAccessible.md
index f8e3ddd..fde8a85 100644
--- a/docs/ProAccessible.md
+++ b/docs/ProAccessible.md
@@ -4,7 +4,7 @@ Given that `F` is a type meeting the [*ProBasicFacade* requirements](ProBasicFac
 
 | Expressions                                 | Semantics                                                    |
 | ------------------------------------------- | ------------------------------------------------------------ |
-| `typename T::template accessor<F, Args...>` | A type that provides accessibility to `proxy`. It shall be a trivial class type and not [final](https://en.cppreference.com/w/cpp/language/final). |
+| `typename T::template accessor<F, Args...>` | A type that provides accessibility to `proxy`. It shall be a *nothrow-default-constructible*, *trivially-copyable* type, and shall not be [final](https://en.cppreference.com/w/cpp/language/final). |
 
 ## See Also
 
diff --git a/proxy.h b/proxy.h
index c5d6f17..9eea33f 100644
--- a/proxy.h
+++ b/proxy.h
@@ -688,12 +688,14 @@ class proxy : public details::facade_traits<F>::base {
 #else
   proxy() noexcept {
     if constexpr (_Traits::has_indirection) {
-      std::ignore = **this;
-      std::ignore = *std::as_const(*this);
-      std::ignore = (*this).operator->();
-      std::ignore = (std::move(*this)).operator->();
-      std::ignore = (std::as_const(*this)).operator->();
-      std::ignore = (std::forward<const proxy&&>(*this)).operator->();
+      if (false) {
+        std::ignore = **this;
+        std::ignore = *std::as_const(*this);
+        std::ignore = (*this).operator->();
+        std::ignore = (std::move(*this)).operator->();
+        std::ignore = (std::as_const(*this)).operator->();
+        std::ignore = (std::forward<const proxy&&>(*this)).operator->();
+      }
     }
   }
 #endif  // NODEBUG
@@ -1167,9 +1169,9 @@ proxy<F> make_proxy(T&& value) {
         ::std::forward<const accessor>(__self), __VA_ARGS__);
 
 #ifdef NODEBUG
-#define ___PRO_DEF_MEM_ACCESSOR_CTOR(...)
+#define ___PRO_GEN_SYMBOL_FOR_MEM_ACCESSOR(...)
 #else
-#define ___PRO_DEF_MEM_ACCESSOR_CTOR(...) \
+#define ___PRO_GEN_SYMBOL_FOR_MEM_ACCESSOR(...) \
     accessor() noexcept { ::std::ignore = &accessor::__VA_ARGS__; }
 #endif  // NODEBUG
 
@@ -1250,7 +1252,7 @@ struct facade_impl {
 #define ___PRO_DEF_UPWARD_CONVERSION_ACCESSOR(Q, SELF, ...) \
     template <class F2, class C> \
     struct accessor<F2, C, proxy<F>() Q> { \
-      ___PRO_DEF_MEM_ACCESSOR_CTOR(__VA_ARGS__) \
+      ___PRO_GEN_SYMBOL_FOR_MEM_ACCESSOR(__VA_ARGS__) \
       __VA_ARGS__ () Q { \
         if (access_proxy<F2>(SELF).has_value()) { \
           return proxy_invoke<C, proxy<F>() Q>(access_proxy<F2>(SELF)); \
@@ -1413,14 +1415,14 @@ struct operator_dispatch;
 #define ___PRO_DEF_LHS_LEFT_OP_ACCESSOR(Q, SELF, ...) \
     template <class F, class C, class R> \
     struct accessor<F, C, R() Q> { \
-      ___PRO_DEF_MEM_ACCESSOR_CTOR(__VA_ARGS__) \
+      ___PRO_GEN_SYMBOL_FOR_MEM_ACCESSOR(__VA_ARGS__) \
       R __VA_ARGS__ () Q \
           { return proxy_invoke<C, R() Q>(access_proxy<F>(SELF)); } \
     }
 #define ___PRO_DEF_LHS_ANY_OP_ACCESSOR(Q, SELF, ...) \
     template <class F, class C, class R, class... Args> \
     struct accessor<F, C, R(Args...) Q> { \
-      ___PRO_DEF_MEM_ACCESSOR_CTOR(__VA_ARGS__) \
+      ___PRO_GEN_SYMBOL_FOR_MEM_ACCESSOR(__VA_ARGS__) \
       R __VA_ARGS__ (Args... args) Q { \
         return proxy_invoke<C, R(Args...) Q>( \
             access_proxy<F>(SELF), std::forward<Args>(args)...); \
@@ -1486,7 +1488,7 @@ struct operator_dispatch;
 #define ___PRO_DEF_LHS_ASSIGNMENT_OP_ACCESSOR(Q, SELF, ...) \
     template <class F, class C, class R, class Arg> \
     struct accessor<F, C, R(Arg) Q> { \
-      ___PRO_DEF_MEM_ACCESSOR_CTOR(__VA_ARGS__) \
+      ___PRO_GEN_SYMBOL_FOR_MEM_ACCESSOR(__VA_ARGS__) \
       decltype(auto) __VA_ARGS__ (Arg arg) Q { \
         proxy_invoke<C, R(Arg) Q>( \
             access_proxy<F>(SELF), std::forward<Arg>(arg)); \
@@ -1604,7 +1606,7 @@ struct operator_dispatch<"[]", false> {
 #define ___PRO_DEF_CONVERSION_ACCESSOR(Q, SELF, ...) \
     template <class F, class C> \
     struct accessor<F, C, T() Q> { \
-      ___PRO_DEF_MEM_ACCESSOR_CTOR(__VA_ARGS__) \
+      ___PRO_GEN_SYMBOL_FOR_MEM_ACCESSOR(__VA_ARGS__) \
       explicit(Expl) __VA_ARGS__ () Q \
           { return proxy_invoke<C, T() Q>(access_proxy<F>(SELF)); } \
     }
@@ -1632,7 +1634,7 @@ struct conversion_dispatch {
 #define ___PRO_DEF_MEM_ACCESSOR(__Q, __SELF, ...) \
     template <class __F, class __C, class __R, class... __Args> \
     struct accessor<__F, __C, __R(__Args...) __Q> { \
-      ___PRO_DEF_MEM_ACCESSOR_CTOR(__VA_ARGS__) \
+      ___PRO_GEN_SYMBOL_FOR_MEM_ACCESSOR(__VA_ARGS__) \
       __R __VA_ARGS__ (__Args... __args) __Q { \
         return ::pro::proxy_invoke<__C, __R(__Args...) __Q>( \
             ::pro::access_proxy<__F>(__SELF), \

From de20dffcd34b85f8e553db3bb25e60b2e9447fc4 Mon Sep 17 00:00:00 2001
From: Mingxin Wang <mingxwa@microsoft.com>
Date: Mon, 18 Nov 2024 20:59:27 +0800
Subject: [PATCH 4/5] Resolve comments

---
 proxy.h | 61 ++++++++++++++++++++++++++++++++-------------------------
 1 file changed, 34 insertions(+), 27 deletions(-)

diff --git a/proxy.h b/proxy.h
index 9eea33f..cc34ee0 100644
--- a/proxy.h
+++ b/proxy.h
@@ -450,9 +450,11 @@ struct lifetime_meta_traits<MP, constraint_level::nontrivial>
 template <template <bool> class MP, constraint_level C>
 using lifetime_meta_t = typename lifetime_meta_traits<MP, C>::type;
 
+template <class F> struct proxy_indirect_accessor;
 template <class... As>
 class ___PRO_ENFORCE_EBO composite_accessor_impl : public As... {
   template <class> friend class pro::proxy;
+  template <class F> friend struct proxy_indirect_accessor;
 
   composite_accessor_impl() noexcept = default;
   composite_accessor_impl(const composite_accessor_impl&) noexcept = default;
@@ -513,7 +515,6 @@ consteval bool is_facade_constraints_well_formed() {
   }
   return false;
 }
-struct empty_proxy_base {};
 template <class F, class... Cs>
 struct facade_conv_traits_impl : inapplicable_traits {};
 template <class F, class... Cs> requires(conv_traits<Cs>::applicable && ...)
@@ -568,12 +569,14 @@ struct facade_traits<F>
   using direct_accessor = merged_composite_accessor<
       typename facade_traits::conv_direct_accessor,
       typename facade_traits::refl_direct_accessor>;
-  using base = std::conditional_t<std::is_same_v<direct_accessor,
-      composite_accessor_impl<>>, empty_proxy_base, direct_accessor>;
   static constexpr bool has_indirection = !std::is_same_v<
       typename facade_traits::indirect_accessor, composite_accessor_impl<>>;
 };
 
+template <class F> struct proxy_indirect_accessor {};
+template <class F> requires(facade_traits<F>::has_indirection)
+struct proxy_indirect_accessor<F> : facade_traits<F>::indirect_accessor {};
+
 using ptr_prototype = void*[2];
 
 template <class M>
@@ -677,28 +680,30 @@ concept proxiable = facade<F> && sizeof(P) <= F::constraints.max_size &&
     details::facade_traits<F>::template refl_applicable_ptr<P>;
 
 template <class F>
-class proxy : public details::facade_traits<F>::base {
+class proxy : public details::facade_traits<F>::direct_accessor {
   static_assert(facade<F>);
   friend struct details::proxy_helper<F>;
   using _Traits = details::facade_traits<F>;
+  using _IA = details::proxy_indirect_accessor<F>;
 
  public:
-#ifdef NODEBUG
+#ifdef NDEBUG
   proxy() noexcept = default;
 #else
   proxy() noexcept {
     if constexpr (_Traits::has_indirection) {
-      if (false) {
-        std::ignore = **this;
-        std::ignore = *std::as_const(*this);
-        std::ignore = (*this).operator->();
-        std::ignore = (std::move(*this)).operator->();
-        std::ignore = (std::as_const(*this)).operator->();
-        std::ignore = (std::forward<const proxy&&>(*this)).operator->();
-      }
+      std::ignore = static_cast<_IA* (proxy::*)() noexcept>(&proxy::operator->);
+      std::ignore = static_cast<const _IA* (proxy::*)() const noexcept>(
+          &proxy::operator->);
+      std::ignore = static_cast<_IA& (proxy::*)() &>(&proxy::operator*);
+      std::ignore = static_cast<const _IA& (proxy::*)() const&>(
+          &proxy::operator*);
+      std::ignore = static_cast<_IA&& (proxy::*)() &&>(&proxy::operator*);
+      std::ignore = static_cast<const _IA&& (proxy::*)() const&&>(
+          &proxy::operator*);
     }
   }
-#endif  // NODEBUG
+#endif  // NDEBUG
   proxy(std::nullptr_t) noexcept : proxy() {}
   proxy(const proxy&) noexcept requires(F::constraints.copyability ==
       constraint_level::trivial) = default;
@@ -846,18 +851,18 @@ class proxy : public details::facade_traits<F>::base {
       requires(std::is_constructible_v<P, std::initializer_list<U>&, Args...> &&
           F::constraints.destructibility >= constraint_level::nontrivial)
       { reset(); return initialize<P>(il, std::forward<Args>(args)...); }
-  auto operator->() noexcept requires(_Traits::has_indirection)
+  _IA* operator->() noexcept requires(_Traits::has_indirection)
       { return std::addressof(ia_); }
-  auto operator->() const noexcept requires(_Traits::has_indirection)
+  const _IA* operator->() const noexcept requires(_Traits::has_indirection)
       { return std::addressof(ia_); }
-  auto& operator*() & noexcept requires(_Traits::has_indirection)
+  _IA& operator*() & noexcept requires(_Traits::has_indirection)
       { return ia_; }
-  auto& operator*() const& noexcept requires(_Traits::has_indirection)
+  const _IA& operator*() const& noexcept requires(_Traits::has_indirection)
       { return ia_; }
-  auto&& operator*() && noexcept requires(_Traits::has_indirection)
-      { return std::forward<typename _Traits::indirect_accessor>(ia_); }
-  auto&& operator*() const&& noexcept requires(_Traits::has_indirection)
-      { return std::forward<const typename _Traits::indirect_accessor>(ia_); }
+  _IA&& operator*() && noexcept requires(_Traits::has_indirection)
+      { return std::forward<_IA>(ia_); }
+  const _IA&& operator*() const&& noexcept requires(_Traits::has_indirection)
+      { return std::forward<const _IA>(ia_); }
 
   friend void swap(proxy& lhs, proxy& rhs) noexcept(noexcept(lhs.swap(rhs)))
       { lhs.swap(rhs); }
@@ -876,7 +881,7 @@ class proxy : public details::facade_traits<F>::base {
   }
 
   [[___PRO_NO_UNIQUE_ADDRESS_ATTRIBUTE]]
-  typename _Traits::indirect_accessor ia_;
+  _IA ia_;
   details::meta_ptr<typename _Traits::meta> meta_;
   alignas(F::constraints.max_align) std::byte ptr_[F::constraints.max_size];
 };
@@ -1126,7 +1131,8 @@ proxy<F> make_proxy(T&& value) {
     template <class __F, class __C, class... __Os> \
     struct ___PRO_ENFORCE_EBO accessor { accessor() = delete; }; \
     template <class __F, class __C, class... __Os> \
-        requires(sizeof...(__Os) > 1u) \
+        requires(sizeof...(__Os) > 1u && \
+            (::std::is_constructible_v<accessor<__F, __C, __Os>> && ...)) \
     struct accessor<__F, __C, __Os...> : accessor<__F, __C, __Os>... \
         { using accessor<__F, __C, __Os>::__VA_ARGS__...; }; \
     __MACRO(, *this, __VA_ARGS__); \
@@ -1147,7 +1153,8 @@ proxy<F> make_proxy(T&& value) {
     template <class __F, class __C, class... __Os> \
     struct ___PRO_ENFORCE_EBO accessor { accessor() = delete; }; \
     template <class __F, class __C, class... __Os> \
-        requires(sizeof...(__Os) > 1u) \
+        requires(sizeof...(__Os) > 1u && \
+            (::std::is_constructible_v<accessor<__F, __C, __Os>> && ...)) \
     struct accessor<__F, __C, __Os...> : accessor<__F, __C, __Os>... {}; \
     __MACRO(,, accessor& __self, __self, __VA_ARGS__); \
     __MACRO(noexcept, noexcept, accessor& __self, __self, __VA_ARGS__); \
@@ -1168,12 +1175,12 @@ proxy<F> make_proxy(T&& value) {
     __MACRO(const&& noexcept, noexcept, const accessor&& __self, \
         ::std::forward<const accessor>(__self), __VA_ARGS__);
 
-#ifdef NODEBUG
+#ifdef NDEBUG
 #define ___PRO_GEN_SYMBOL_FOR_MEM_ACCESSOR(...)
 #else
 #define ___PRO_GEN_SYMBOL_FOR_MEM_ACCESSOR(...) \
     accessor() noexcept { ::std::ignore = &accessor::__VA_ARGS__; }
-#endif  // NODEBUG
+#endif  // NDEBUG
 
 namespace details {
 

From 642dfef93620ea4237a102199dfc43315cd32d85 Mon Sep 17 00:00:00 2001
From: Mingxin Wang <mingxwa@microsoft.com>
Date: Tue, 19 Nov 2024 13:38:58 +0800
Subject: [PATCH 5/5] Typo

---
 proxy.h | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/proxy.h b/proxy.h
index cc34ee0..a78221e 100644
--- a/proxy.h
+++ b/proxy.h
@@ -695,11 +695,12 @@ class proxy : public details::facade_traits<F>::direct_accessor {
       std::ignore = static_cast<_IA* (proxy::*)() noexcept>(&proxy::operator->);
       std::ignore = static_cast<const _IA* (proxy::*)() const noexcept>(
           &proxy::operator->);
-      std::ignore = static_cast<_IA& (proxy::*)() &>(&proxy::operator*);
-      std::ignore = static_cast<const _IA& (proxy::*)() const&>(
+      std::ignore = static_cast<_IA& (proxy::*)() & noexcept>(&proxy::operator*);
+      std::ignore = static_cast<const _IA& (proxy::*)() const& noexcept>(
           &proxy::operator*);
-      std::ignore = static_cast<_IA&& (proxy::*)() &&>(&proxy::operator*);
-      std::ignore = static_cast<const _IA&& (proxy::*)() const&&>(
+      std::ignore = static_cast<_IA&& (proxy::*)() && noexcept>(
+          &proxy::operator*);
+      std::ignore = static_cast<const _IA&& (proxy::*)() const&& noexcept>(
           &proxy::operator*);
     }
   }