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[libc++] [C++2b] [P1048] Add is_scoped_enum and is_scoped_enum_v.
* https://wg21.link/p1048 Reviewed By: ldionne, #libc Differential Revision: https://reviews.llvm.org/D94409
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8 files changed

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lines changed

‎libcxx/docs/Cxx2bStatusPaperStatus.csv

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@@ -1,6 +1,6 @@
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"Paper #","Group","Paper Name","Meeting","Status","First released version"
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"`P0881R7 <https://wg21.link/P0881R7>`__","LWG","A Proposal to add stacktrace library","Autumn 2020","",""
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"`P0943R6 <https://wg21.link/P0943R6>`__","LWG","Support C atomics in C++","Autumn 2020","",""
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"`P1048R1 <https://wg21.link/P1048R1>`__","LWG","A proposal for a type trait to detect scoped enumerations","Autumn 2020","",""
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"`P1048R1 <https://wg21.link/P1048R1>`__","LWG","A proposal for a type trait to detect scoped enumerations","Autumn 2020","|Complete|","12.0"
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"`P1679R3 <https://wg21.link/P1679R3>`__","LWG","string contains function","Autumn 2020","",""
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"","","","","",""

‎libcxx/docs/FeatureTestMacroTable.rst

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@@ -292,7 +292,7 @@ Status
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------------------------------------------------- -----------------
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**C++ 2b**
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-------------------------------------------------------------------
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``__cpp_lib_is_scoped_enum`` *unimplemented*
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``__cpp_lib_is_scoped_enum`` ``202011L``
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------------------------------------------------- -----------------
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``__cpp_lib_stacktrace`` *unimplemented*
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------------------------------------------------- -----------------

‎libcxx/include/type_traits

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@@ -51,6 +51,7 @@ namespace std
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template <class T> struct is_arithmetic;
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template <class T> struct is_fundamental;
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template <class T> struct is_member_pointer;
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template <class T> struct is_scoped_enum; // C++2b
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template <class T> struct is_scalar;
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template <class T> struct is_object;
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template <class T> struct is_compound;
@@ -284,6 +285,8 @@ namespace std
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= is_compound<T>::value; // C++17
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template <class T> inline constexpr bool is_member_pointer_v
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= is_member_pointer<T>::value; // C++17
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template <class T> inline constexpr bool is_scoped_enum_v
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= is_scoped_enum<T>::value; // C++2b
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// See C++14 20.10.4.3, type properties
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template <class T> inline constexpr bool is_const_v
@@ -4177,6 +4180,25 @@ struct __has_operator_addressof
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#endif // _LIBCPP_CXX03_LANG
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// is_scoped_enum [meta.unary.prop]
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#if _LIBCPP_STD_VER > 20
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template <class _Tp, bool = is_enum_v<_Tp> >
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struct __is_scoped_enum_helper : false_type {};
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template <class _Tp>
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struct __is_scoped_enum_helper<_Tp, true>
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: public bool_constant<!is_convertible_v<_Tp, underlying_type_t<_Tp> > > {};
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template <class _Tp>
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struct _LIBCPP_TEMPLATE_VIS is_scoped_enum
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: public __is_scoped_enum_helper<_Tp> {};
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template <class _Tp>
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_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_scoped_enum_v =
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is_scoped_enum<_Tp>::value;
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#endif
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#if _LIBCPP_STD_VER > 14
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template <class... _Args>

‎libcxx/include/version

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@@ -355,7 +355,7 @@ __cpp_lib_void_t 201411L <type_traits>
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#endif
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#if _LIBCPP_STD_VER > 20
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// # define __cpp_lib_is_scoped_enum 202011L
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# define __cpp_lib_is_scoped_enum 202011L
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// # define __cpp_lib_stacktrace 202011L
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// # define __cpp_lib_stdatomic_h 202011L
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// # define __cpp_lib_string_contains 202011L

‎libcxx/test/std/language.support/support.limits/support.limits.general/type_traits.version.pass.cpp

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@@ -638,17 +638,11 @@
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# endif
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# endif
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# if !defined(_LIBCPP_VERSION)
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# ifndef __cpp_lib_is_scoped_enum
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# error "__cpp_lib_is_scoped_enum should be defined in c++2b"
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# endif
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# if __cpp_lib_is_scoped_enum != 202011L
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# error "__cpp_lib_is_scoped_enum should have the value 202011L in c++2b"
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# endif
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# else // _LIBCPP_VERSION
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# ifdef __cpp_lib_is_scoped_enum
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# error "__cpp_lib_is_scoped_enum should not be defined because it is unimplemented in libc++!"
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# endif
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#ifndef __cpp_lib_is_scoped_enum
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#error "__cpp_lib_is_scoped_enum should be defined in c++2b"
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#endif
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#if __cpp_lib_is_scoped_enum != 202011L
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#error "__cpp_lib_is_scoped_enum should have the value 202011L in c++2b"
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# endif
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# ifndef __cpp_lib_is_swappable

‎libcxx/test/std/language.support/support.limits/support.limits.general/version.version.pass.cpp

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@@ -3983,17 +3983,11 @@
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# endif
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# endif
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# if !defined(_LIBCPP_VERSION)
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# ifndef __cpp_lib_is_scoped_enum
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# error "__cpp_lib_is_scoped_enum should be defined in c++2b"
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# endif
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# if __cpp_lib_is_scoped_enum != 202011L
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# error "__cpp_lib_is_scoped_enum should have the value 202011L in c++2b"
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# endif
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# else // _LIBCPP_VERSION
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# ifdef __cpp_lib_is_scoped_enum
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# error "__cpp_lib_is_scoped_enum should not be defined because it is unimplemented in libc++!"
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# endif
3986+
#ifndef __cpp_lib_is_scoped_enum
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#error "__cpp_lib_is_scoped_enum should be defined in c++2b"
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#endif
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#if __cpp_lib_is_scoped_enum != 202011L
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#error "__cpp_lib_is_scoped_enum should have the value 202011L in c++2b"
39973991
# endif
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# ifndef __cpp_lib_is_swappable

‎libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/is_scoped_enum.pass.cpp

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//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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// UNSUPPORTED: c++03, c++11, c++14, c++17, c++2a
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// type_traits
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// is_scoped_enum // C++2b
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#include <type_traits>
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#include <cstddef> // for std::nullptr_t
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#include "test_macros.h"
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template <class T>
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void test_positive() {
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static_assert(std::is_scoped_enum<T>::value);
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static_assert(std::is_scoped_enum<const T>::value);
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static_assert(std::is_scoped_enum<volatile T>::value);
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static_assert(std::is_scoped_enum<const volatile T>::value);
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static_assert(std::is_scoped_enum_v<T>);
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static_assert(std::is_scoped_enum_v<const T>);
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static_assert(std::is_scoped_enum_v<volatile T>);
29+
static_assert(std::is_scoped_enum_v<const volatile T>);
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}
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template <class T>
33+
void test_negative() {
34+
static_assert(!std::is_scoped_enum<T>::value);
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static_assert(!std::is_scoped_enum<const T>::value);
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static_assert(!std::is_scoped_enum<volatile T>::value);
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static_assert(!std::is_scoped_enum<const volatile T>::value);
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static_assert(!std::is_scoped_enum_v<T>);
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static_assert(!std::is_scoped_enum_v<const T>);
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static_assert(!std::is_scoped_enum_v<volatile T>);
42+
static_assert(!std::is_scoped_enum_v<const volatile T>);
43+
}
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class Empty {};
46+
47+
class NotEmpty {
48+
virtual ~NotEmpty();
49+
};
50+
51+
union Union {};
52+
53+
struct bit_zero {
54+
int : 0;
55+
};
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57+
class Abstract {
58+
virtual ~Abstract() = 0;
59+
};
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enum Enum { zero, one };
62+
enum class CEnum1 { zero, one };
63+
enum class CEnum2;
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enum class CEnum3 : short;
65+
struct incomplete_type;
66+
67+
using FunctionPtr = void (*)();
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using FunctionType = void();
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struct TestMembers {
71+
static int static_method(int) { return 0; }
72+
int method() { return 0; }
73+
74+
enum E1 { m_zero, m_one };
75+
enum class CE1;
76+
};
77+
78+
void func1();
79+
int func2(int);
80+
81+
int main(int, char**) {
82+
test_positive<CEnum1>();
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test_positive<CEnum2>();
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test_positive<CEnum3>();
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test_positive<TestMembers::CE1>();
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87+
test_negative<Enum>();
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test_negative<TestMembers::E1>();
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test_negative<std::nullptr_t>();
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test_negative<void>();
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test_negative<int>();
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test_negative<int&>();
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test_negative<int&&>();
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test_negative<int*>();
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test_negative<double>();
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test_negative<const int*>();
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test_negative<char[3]>();
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test_negative<char[]>();
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test_negative<Union>();
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test_negative<Empty>();
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test_negative<bit_zero>();
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test_negative<NotEmpty>();
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test_negative<Abstract>();
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test_negative<FunctionPtr>();
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test_negative<FunctionType>();
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test_negative<incomplete_type>();
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test_negative<int TestMembers::*>();
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test_negative<void (TestMembers::*)()>();
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test_negative<decltype(func1)>();
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test_negative<decltype(&func1)>();
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test_negative<decltype(func2)>();
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test_negative<decltype(&func2)>();
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test_negative<decltype(TestMembers::static_method)>();
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test_negative<decltype(&TestMembers::static_method)>();
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test_negative<decltype(&TestMembers::method)>();
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return 0;
120+
}

‎libcxx/utils/generate_feature_test_macro_components.py

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@@ -368,7 +368,6 @@ def add_version_header(tc):
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"name": "__cpp_lib_is_scoped_enum",
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"values": { "c++2b": 202011 },
370370
"headers": ["type_traits"],
371-
"unimplemented": True,
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}, {
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"name": "__cpp_lib_is_swappable",
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"values": { "c++17": 201603 },

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