Skip to content

[libc++][NFC] Make enable_ifs in <optional> consistent #127184

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Feb 15, 2025

Conversation

philnik777
Copy link
Contributor

We've documented the preferred enable_if style in the coding guidelines. This updates <optional> to conform to them

@philnik777 philnik777 marked this pull request as ready for review February 15, 2025 09:38
@philnik777 philnik777 requested a review from a team as a code owner February 15, 2025 09:38
@philnik777 philnik777 merged commit 4887e41 into llvm:main Feb 15, 2025
80 checks passed
@llvmbot llvmbot added the libc++ libc++ C++ Standard Library. Not GNU libstdc++. Not libc++abi. label Feb 15, 2025
@llvmbot
Copy link
Member

llvmbot commented Feb 15, 2025

@llvm/pr-subscribers-libcxx

Author: Nikolas Klauser (philnik777)

Changes

We've documented the preferred enable_if style in the coding guidelines. This updates &lt;optional&gt; to conform to them


Full diff: https://github.com/llvm/llvm-project/pull/127184.diff

1 Files Affected:

  • (modified) libcxx/include/optional (+114-121)
diff --git a/libcxx/include/optional b/libcxx/include/optional
index c325140ee66f2..db236f86e74dd 100644
--- a/libcxx/include/optional
+++ b/libcxx/include/optional
@@ -672,44 +672,41 @@ public:
   _LIBCPP_HIDE_FROM_ABI constexpr optional(optional&&)      = default;
   _LIBCPP_HIDE_FROM_ABI constexpr optional(nullopt_t) noexcept {}
 
-  template <
-      class _InPlaceT,
-      class... _Args,
-      class = enable_if_t< _And< _IsSame<_InPlaceT, in_place_t>, is_constructible<value_type, _Args...> >::value > >
+  template <class _InPlaceT,
+            class... _Args,
+            enable_if_t<_And<_IsSame<_InPlaceT, in_place_t>, is_constructible<value_type, _Args...>>::value, int> = 0>
   _LIBCPP_HIDE_FROM_ABI constexpr explicit optional(_InPlaceT, _Args&&... __args)
       : __base(in_place, std::forward<_Args>(__args)...) {}
 
   template <class _Up,
             class... _Args,
-            class = enable_if_t< is_constructible_v<value_type, initializer_list<_Up>&, _Args...>> >
+            enable_if_t<is_constructible_v<value_type, initializer_list<_Up>&, _Args...>, int> = 0>
   _LIBCPP_HIDE_FROM_ABI constexpr explicit optional(in_place_t, initializer_list<_Up> __il, _Args&&... __args)
       : __base(in_place, __il, std::forward<_Args>(__args)...) {}
 
-  template <class _Up                                                                         = value_type,
-            enable_if_t< _CheckOptionalArgsCtor<_Up>::template __enable_implicit<_Up>(), int> = 0>
+  template <class _Up                                                                        = value_type,
+            enable_if_t<_CheckOptionalArgsCtor<_Up>::template __enable_implicit<_Up>(), int> = 0>
   _LIBCPP_HIDE_FROM_ABI constexpr optional(_Up&& __v) : __base(in_place, std::forward<_Up>(__v)) {}
 
-  template <class _Up, enable_if_t< _CheckOptionalArgsCtor<_Up>::template __enable_explicit<_Up>(), int> = 0>
+  template <class _Up, enable_if_t<_CheckOptionalArgsCtor<_Up>::template __enable_explicit<_Up>(), int> = 0>
   _LIBCPP_HIDE_FROM_ABI constexpr explicit optional(_Up&& __v) : __base(in_place, std::forward<_Up>(__v)) {}
 
   // LWG2756: conditionally explicit conversion from const optional<_Up>&
-  template <class _Up,
-            enable_if_t< _CheckOptionalLikeCtor<_Up, _Up const&>::template __enable_implicit<_Up>(), int> = 0>
+  template <class _Up, enable_if_t<_CheckOptionalLikeCtor<_Up, _Up const&>::template __enable_implicit<_Up>(), int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 optional(const optional<_Up>& __v) {
     this->__construct_from(__v);
   }
-  template <class _Up,
-            enable_if_t< _CheckOptionalLikeCtor<_Up, _Up const&>::template __enable_explicit<_Up>(), int> = 0>
+  template <class _Up, enable_if_t<_CheckOptionalLikeCtor<_Up, _Up const&>::template __enable_explicit<_Up>(), int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit optional(const optional<_Up>& __v) {
     this->__construct_from(__v);
   }
 
   // LWG2756: conditionally explicit conversion from optional<_Up>&&
-  template <class _Up, enable_if_t< _CheckOptionalLikeCtor<_Up, _Up&&>::template __enable_implicit<_Up>(), int> = 0>
+  template <class _Up, enable_if_t<_CheckOptionalLikeCtor<_Up, _Up&&>::template __enable_implicit<_Up>(), int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 optional(optional<_Up>&& __v) {
     this->__construct_from(std::move(__v));
   }
-  template <class _Up, enable_if_t< _CheckOptionalLikeCtor<_Up, _Up&&>::template __enable_explicit<_Up>(), int> = 0>
+  template <class _Up, enable_if_t<_CheckOptionalLikeCtor<_Up, _Up&&>::template __enable_explicit<_Up>(), int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit optional(optional<_Up>&& __v) {
     this->__construct_from(std::move(__v));
   }
@@ -718,7 +715,7 @@ public:
   template <class _Tag,
             class _Fp,
             class... _Args,
-            __enable_if_t<_IsSame<_Tag, __optional_construct_from_invoke_tag>::value, int> = 0>
+            enable_if_t<_IsSame<_Tag, __optional_construct_from_invoke_tag>::value, int> = 0>
   _LIBCPP_HIDE_FROM_ABI constexpr explicit optional(_Tag, _Fp&& __f, _Args&&... __args)
       : __base(__optional_construct_from_invoke_tag{}, std::forward<_Fp>(__f), std::forward<_Args>(__args)...) {}
 #    endif
@@ -732,12 +729,12 @@ public:
   _LIBCPP_HIDE_FROM_ABI constexpr optional& operator=(optional&&)      = default;
 
   // LWG2756
-  template <
-      class _Up = value_type,
-      class     = enable_if_t< _And< _IsNotSame<__remove_cvref_t<_Up>, optional>,
-                                     _Or< _IsNotSame<__remove_cvref_t<_Up>, value_type>, _Not<is_scalar<value_type>> >,
-                                     is_constructible<value_type, _Up>,
-                                     is_assignable<value_type&, _Up> >::value> >
+  template <class _Up        = value_type,
+            enable_if_t<_And<_IsNotSame<__remove_cvref_t<_Up>, optional>,
+                             _Or<_IsNotSame<__remove_cvref_t<_Up>, value_type>, _Not<is_scalar<value_type>>>,
+                             is_constructible<value_type, _Up>,
+                             is_assignable<value_type&, _Up>>::value,
+                        int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 optional& operator=(_Up&& __v) {
     if (this->has_value())
       this->__get() = std::forward<_Up>(__v);
@@ -747,21 +744,20 @@ public:
   }
 
   // LWG2756
-  template <class _Up,
-            enable_if_t< _CheckOptionalLikeAssign<_Up, _Up const&>::template __enable_assign<_Up>(), int> = 0>
+  template <class _Up, enable_if_t<_CheckOptionalLikeAssign<_Up, _Up const&>::template __enable_assign<_Up>(), int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 optional& operator=(const optional<_Up>& __v) {
     this->__assign_from(__v);
     return *this;
   }
 
   // LWG2756
-  template <class _Up, enable_if_t< _CheckOptionalLikeCtor<_Up, _Up&&>::template __enable_assign<_Up>(), int> = 0>
+  template <class _Up, enable_if_t<_CheckOptionalLikeCtor<_Up, _Up&&>::template __enable_assign<_Up>(), int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 optional& operator=(optional<_Up>&& __v) {
     this->__assign_from(std::move(__v));
     return *this;
   }
 
-  template <class... _Args, class = enable_if_t< is_constructible_v<value_type, _Args...> > >
+  template <class... _Args, enable_if_t<is_constructible_v<value_type, _Args...>, int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Tp& emplace(_Args&&... __args) {
     reset();
     this->__construct(std::forward<_Args>(__args)...);
@@ -770,7 +766,7 @@ public:
 
   template <class _Up,
             class... _Args,
-            class = enable_if_t< is_constructible_v<value_type, initializer_list<_Up>&, _Args...> > >
+            enable_if_t<is_constructible_v<value_type, initializer_list<_Up>&, _Args...>, int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Tp& emplace(initializer_list<_Up> __il, _Args&&... __args) {
     reset();
     this->__construct(__il, std::forward<_Args>(__args)...);
@@ -982,17 +978,15 @@ public:
   using __base::reset;
 };
 
-#    if _LIBCPP_STD_VER >= 17
 template <class _Tp>
 optional(_Tp) -> optional<_Tp>;
-#    endif
 
 // Comparisons between optionals
-template <class _Tp, class _Up>
-_LIBCPP_HIDE_FROM_ABI constexpr enable_if_t<
-    is_convertible_v<decltype(std::declval<const _Tp&>() == std::declval<const _Up&>()), bool>,
-    bool >
-operator==(const optional<_Tp>& __x, const optional<_Up>& __y) {
+template <
+    class _Tp,
+    class _Up,
+    enable_if_t<is_convertible_v<decltype(std::declval<const _Tp&>() == std::declval<const _Up&>()), bool>, int> = 0>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator==(const optional<_Tp>& __x, const optional<_Up>& __y) {
   if (static_cast<bool>(__x) != static_cast<bool>(__y))
     return false;
   if (!static_cast<bool>(__x))
@@ -1000,11 +994,11 @@ operator==(const optional<_Tp>& __x, const optional<_Up>& __y) {
   return *__x == *__y;
 }
 
-template <class _Tp, class _Up>
-_LIBCPP_HIDE_FROM_ABI constexpr enable_if_t<
-    is_convertible_v<decltype(std::declval<const _Tp&>() != std::declval<const _Up&>()), bool>,
-    bool >
-operator!=(const optional<_Tp>& __x, const optional<_Up>& __y) {
+template <
+    class _Tp,
+    class _Up,
+    enable_if_t<is_convertible_v<decltype(std::declval<const _Tp&>() != std::declval<const _Up&>()), bool>, int> = 0>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator!=(const optional<_Tp>& __x, const optional<_Up>& __y) {
   if (static_cast<bool>(__x) != static_cast<bool>(__y))
     return true;
   if (!static_cast<bool>(__x))
@@ -1012,11 +1006,11 @@ operator!=(const optional<_Tp>& __x, const optional<_Up>& __y) {
   return *__x != *__y;
 }
 
-template <class _Tp, class _Up>
-_LIBCPP_HIDE_FROM_ABI constexpr enable_if_t<
-    is_convertible_v<decltype(std::declval<const _Tp&>() < std::declval<const _Up&>()), bool>,
-    bool >
-operator<(const optional<_Tp>& __x, const optional<_Up>& __y) {
+template <
+    class _Tp,
+    class _Up,
+    enable_if_t<is_convertible_v<decltype(std::declval<const _Tp&>() < std::declval<const _Up&>()), bool>, int> = 0>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator<(const optional<_Tp>& __x, const optional<_Up>& __y) {
   if (!static_cast<bool>(__y))
     return false;
   if (!static_cast<bool>(__x))
@@ -1024,11 +1018,11 @@ operator<(const optional<_Tp>& __x, const optional<_Up>& __y) {
   return *__x < *__y;
 }
 
-template <class _Tp, class _Up>
-_LIBCPP_HIDE_FROM_ABI constexpr enable_if_t<
-    is_convertible_v<decltype(std::declval<const _Tp&>() > std::declval<const _Up&>()), bool>,
-    bool >
-operator>(const optional<_Tp>& __x, const optional<_Up>& __y) {
+template <
+    class _Tp,
+    class _Up,
+    enable_if_t<is_convertible_v<decltype(std::declval<const _Tp&>() > std::declval<const _Up&>()), bool>, int> = 0>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator>(const optional<_Tp>& __x, const optional<_Up>& __y) {
   if (!static_cast<bool>(__x))
     return false;
   if (!static_cast<bool>(__y))
@@ -1036,11 +1030,11 @@ operator>(const optional<_Tp>& __x, const optional<_Up>& __y) {
   return *__x > *__y;
 }
 
-template <class _Tp, class _Up>
-_LIBCPP_HIDE_FROM_ABI constexpr enable_if_t<
-    is_convertible_v<decltype(std::declval<const _Tp&>() <= std::declval<const _Up&>()), bool>,
-    bool >
-operator<=(const optional<_Tp>& __x, const optional<_Up>& __y) {
+template <
+    class _Tp,
+    class _Up,
+    enable_if_t<is_convertible_v<decltype(std::declval<const _Tp&>() <= std::declval<const _Up&>()), bool>, int> = 0>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator<=(const optional<_Tp>& __x, const optional<_Up>& __y) {
   if (!static_cast<bool>(__x))
     return true;
   if (!static_cast<bool>(__y))
@@ -1048,11 +1042,11 @@ operator<=(const optional<_Tp>& __x, const optional<_Up>& __y) {
   return *__x <= *__y;
 }
 
-template <class _Tp, class _Up>
-_LIBCPP_HIDE_FROM_ABI constexpr enable_if_t<
-    is_convertible_v<decltype(std::declval<const _Tp&>() >= std::declval<const _Up&>()), bool>,
-    bool >
-operator>=(const optional<_Tp>& __x, const optional<_Up>& __y) {
+template <
+    class _Tp,
+    class _Up,
+    enable_if_t<is_convertible_v<decltype(std::declval<const _Tp&>() >= std::declval<const _Up&>()), bool>, int> = 0>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator>=(const optional<_Tp>& __x, const optional<_Up>& __y) {
   if (!static_cast<bool>(__y))
     return true;
   if (!static_cast<bool>(__x))
@@ -1145,99 +1139,99 @@ _LIBCPP_HIDE_FROM_ABI constexpr strong_ordering operator<=>(const optional<_Tp>&
 #    endif // _LIBCPP_STD_VER <= 17
 
 // Comparisons with T
-template <class _Tp, class _Up>
-_LIBCPP_HIDE_FROM_ABI constexpr enable_if_t<
-    is_convertible_v<decltype(std::declval<const _Tp&>() == std::declval<const _Up&>()), bool>,
-    bool >
-operator==(const optional<_Tp>& __x, const _Up& __v) {
+template <
+    class _Tp,
+    class _Up,
+    enable_if_t<is_convertible_v<decltype(std::declval<const _Tp&>() == std::declval<const _Up&>()), bool>, int> = 0>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator==(const optional<_Tp>& __x, const _Up& __v) {
   return static_cast<bool>(__x) ? *__x == __v : false;
 }
 
-template <class _Tp, class _Up>
-_LIBCPP_HIDE_FROM_ABI constexpr enable_if_t<
-    is_convertible_v<decltype(std::declval<const _Tp&>() == std::declval<const _Up&>()), bool>,
-    bool >
-operator==(const _Tp& __v, const optional<_Up>& __x) {
+template <
+    class _Tp,
+    class _Up,
+    enable_if_t<is_convertible_v<decltype(std::declval<const _Tp&>() == std::declval<const _Up&>()), bool>, int> = 0>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator==(const _Tp& __v, const optional<_Up>& __x) {
   return static_cast<bool>(__x) ? __v == *__x : false;
 }
 
-template <class _Tp, class _Up>
-_LIBCPP_HIDE_FROM_ABI constexpr enable_if_t<
-    is_convertible_v<decltype(std::declval<const _Tp&>() != std::declval<const _Up&>()), bool>,
-    bool >
-operator!=(const optional<_Tp>& __x, const _Up& __v) {
+template <
+    class _Tp,
+    class _Up,
+    enable_if_t<is_convertible_v<decltype(std::declval<const _Tp&>() != std::declval<const _Up&>()), bool>, int> = 0>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator!=(const optional<_Tp>& __x, const _Up& __v) {
   return static_cast<bool>(__x) ? *__x != __v : true;
 }
 
-template <class _Tp, class _Up>
-_LIBCPP_HIDE_FROM_ABI constexpr enable_if_t<
-    is_convertible_v<decltype(std::declval<const _Tp&>() != std::declval<const _Up&>()), bool>,
-    bool >
-operator!=(const _Tp& __v, const optional<_Up>& __x) {
+template <
+    class _Tp,
+    class _Up,
+    enable_if_t<is_convertible_v<decltype(std::declval<const _Tp&>() != std::declval<const _Up&>()), bool>, int> = 0>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator!=(const _Tp& __v, const optional<_Up>& __x) {
   return static_cast<bool>(__x) ? __v != *__x : true;
 }
 
-template <class _Tp, class _Up>
-_LIBCPP_HIDE_FROM_ABI constexpr enable_if_t<
-    is_convertible_v<decltype(std::declval<const _Tp&>() < std::declval<const _Up&>()), bool>,
-    bool >
-operator<(const optional<_Tp>& __x, const _Up& __v) {
+template <
+    class _Tp,
+    class _Up,
+    enable_if_t<is_convertible_v<decltype(std::declval<const _Tp&>() < std::declval<const _Up&>()), bool>, int> = 0>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator<(const optional<_Tp>& __x, const _Up& __v) {
   return static_cast<bool>(__x) ? *__x < __v : true;
 }
 
-template <class _Tp, class _Up>
-_LIBCPP_HIDE_FROM_ABI constexpr enable_if_t<
-    is_convertible_v<decltype(std::declval<const _Tp&>() < std::declval<const _Up&>()), bool>,
-    bool >
-operator<(const _Tp& __v, const optional<_Up>& __x) {
+template <
+    class _Tp,
+    class _Up,
+    enable_if_t<is_convertible_v<decltype(std::declval<const _Tp&>() < std::declval<const _Up&>()), bool>, int> = 0>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator<(const _Tp& __v, const optional<_Up>& __x) {
   return static_cast<bool>(__x) ? __v < *__x : false;
 }
 
-template <class _Tp, class _Up>
-_LIBCPP_HIDE_FROM_ABI constexpr enable_if_t<
-    is_convertible_v<decltype(std::declval<const _Tp&>() <= std::declval<const _Up&>()), bool>,
-    bool >
-operator<=(const optional<_Tp>& __x, const _Up& __v) {
+template <
+    class _Tp,
+    class _Up,
+    enable_if_t<is_convertible_v<decltype(std::declval<const _Tp&>() <= std::declval<const _Up&>()), bool>, int> = 0>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator<=(const optional<_Tp>& __x, const _Up& __v) {
   return static_cast<bool>(__x) ? *__x <= __v : true;
 }
 
-template <class _Tp, class _Up>
-_LIBCPP_HIDE_FROM_ABI constexpr enable_if_t<
-    is_convertible_v<decltype(std::declval<const _Tp&>() <= std::declval<const _Up&>()), bool>,
-    bool >
-operator<=(const _Tp& __v, const optional<_Up>& __x) {
+template <
+    class _Tp,
+    class _Up,
+    enable_if_t<is_convertible_v<decltype(std::declval<const _Tp&>() <= std::declval<const _Up&>()), bool>, int> = 0>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator<=(const _Tp& __v, const optional<_Up>& __x) {
   return static_cast<bool>(__x) ? __v <= *__x : false;
 }
 
-template <class _Tp, class _Up>
-_LIBCPP_HIDE_FROM_ABI constexpr enable_if_t<
-    is_convertible_v<decltype(std::declval<const _Tp&>() > std::declval<const _Up&>()), bool>,
-    bool >
-operator>(const optional<_Tp>& __x, const _Up& __v) {
+template <
+    class _Tp,
+    class _Up,
+    enable_if_t<is_convertible_v<decltype(std::declval<const _Tp&>() > std::declval<const _Up&>()), bool>, int> = 0>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator>(const optional<_Tp>& __x, const _Up& __v) {
   return static_cast<bool>(__x) ? *__x > __v : false;
 }
 
-template <class _Tp, class _Up>
-_LIBCPP_HIDE_FROM_ABI constexpr enable_if_t<
-    is_convertible_v<decltype(std::declval<const _Tp&>() > std::declval<const _Up&>()), bool>,
-    bool >
-operator>(const _Tp& __v, const optional<_Up>& __x) {
+template <
+    class _Tp,
+    class _Up,
+    enable_if_t<is_convertible_v<decltype(std::declval<const _Tp&>() > std::declval<const _Up&>()), bool>, int> = 0>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator>(const _Tp& __v, const optional<_Up>& __x) {
   return static_cast<bool>(__x) ? __v > *__x : true;
 }
 
-template <class _Tp, class _Up>
-_LIBCPP_HIDE_FROM_ABI constexpr enable_if_t<
-    is_convertible_v<decltype(std::declval<const _Tp&>() >= std::declval<const _Up&>()), bool>,
-    bool >
-operator>=(const optional<_Tp>& __x, const _Up& __v) {
+template <
+    class _Tp,
+    class _Up,
+    enable_if_t<is_convertible_v<decltype(std::declval<const _Tp&>() >= std::declval<const _Up&>()), bool>, int> = 0>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator>=(const optional<_Tp>& __x, const _Up& __v) {
   return static_cast<bool>(__x) ? *__x >= __v : false;
 }
 
-template <class _Tp, class _Up>
-_LIBCPP_HIDE_FROM_ABI constexpr enable_if_t<
-    is_convertible_v<decltype(std::declval<const _Tp&>() >= std::declval<const _Up&>()), bool>,
-    bool >
-operator>=(const _Tp& __v, const optional<_Up>& __x) {
+template <
+    class _Tp,
+    class _Up,
+    enable_if_t<is_convertible_v<decltype(std::declval<const _Tp&>() >= std::declval<const _Up&>()), bool>, int> = 0>
+_LIBCPP_HIDE_FROM_ABI constexpr bool operator>=(const _Tp& __v, const optional<_Up>& __x) {
   return static_cast<bool>(__x) ? __v >= *__x : true;
 }
 
@@ -1252,9 +1246,8 @@ operator<=>(const optional<_Tp>& __x, const _Up& __v) {
 
 #    endif // _LIBCPP_STD_VER >= 20
 
-template <class _Tp>
-inline _LIBCPP_HIDE_FROM_ABI
-_LIBCPP_CONSTEXPR_SINCE_CXX20 enable_if_t< is_move_constructible_v<_Tp> && is_swappable_v<_Tp>, void >
+template <class _Tp, enable_if_t< is_move_constructible_v<_Tp> && is_swappable_v<_Tp>, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
 swap(optional<_Tp>& __x, optional<_Tp>& __y) noexcept(noexcept(__x.swap(__y))) {
   __x.swap(__y);
 }

@philnik777 philnik777 deleted the optional_enable_if branch February 15, 2025 09:40
sivan-shani pushed a commit to sivan-shani/llvm-project that referenced this pull request Feb 24, 2025
We've documented the preferred `enable_if` style in the coding
guidelines. This updates `<optional>` to conform to them
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
libc++ libc++ C++ Standard Library. Not GNU libstdc++. Not libc++abi.
Projects
None yet
Development

Successfully merging this pull request may close these issues.

2 participants