Remove old code

Signed-off-by: Richard Qin <richard.qin.x@gmail.com>

23 files changed, 0 insertions, 1000 deletions

diff --git a/third_party/libcxx/include/c++/v1/__concepts/arithmetic.h b/third_party/libcxx/include/c++/v1/__concepts/arithmetic.h
deleted file mode 100644
index 64c0200..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/arithmetic.h
+++ /dev/null
@@ -1,43 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_ARITHMETIC_H
-#define _LIBCPP___CONCEPTS_ARITHMETIC_H
-
-#include <__config>
-#include <__type_traits/is_floating_point.h>
-#include <__type_traits/is_integral.h>
-#include <__type_traits/is_signed.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// [concepts.arithmetic], arithmetic concepts
-
-template <class _Tp>
-concept integral = is_integral_v<_Tp>;
-
-template <class _Tp>
-concept signed_integral = integral<_Tp> && is_signed_v<_Tp>;
-
-template <class _Tp>
-concept unsigned_integral = integral<_Tp> && !signed_integral<_Tp>;
-
-template <class _Tp>
-concept floating_point = is_floating_point_v<_Tp>;
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_ARITHMETIC_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/assignable.h b/third_party/libcxx/include/c++/v1/__concepts/assignable.h
deleted file mode 100644
index 7423daa..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/assignable.h
+++ /dev/null
@@ -1,41 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_ASSIGNABLE_H
-#define _LIBCPP___CONCEPTS_ASSIGNABLE_H
-
-#include <__concepts/common_reference_with.h>
-#include <__concepts/same_as.h>
-#include <__config>
-#include <__type_traits/is_reference.h>
-#include <__type_traits/make_const_lvalue_ref.h>
-#include <__utility/forward.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// [concept.assignable]
-
-template <class _Lhs, class _Rhs>
-concept assignable_from =
-    is_lvalue_reference_v<_Lhs> &&
-    common_reference_with<__make_const_lvalue_ref<_Lhs>, __make_const_lvalue_ref<_Rhs>> &&
-    requires(_Lhs __lhs, _Rhs&& __rhs) {
-      { __lhs = std::forward<_Rhs>(__rhs) } -> same_as<_Lhs>;
-    };
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_ASSIGNABLE_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/boolean_testable.h b/third_party/libcxx/include/c++/v1/__concepts/boolean_testable.h
deleted file mode 100644
index b379fe9..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/boolean_testable.h
+++ /dev/null
@@ -1,38 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_BOOLEAN_TESTABLE_H
-#define _LIBCPP___CONCEPTS_BOOLEAN_TESTABLE_H
-
-#include <__concepts/convertible_to.h>
-#include <__config>
-#include <__utility/forward.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// [concepts.booleantestable]
-
-template <class _Tp>
-concept __boolean_testable_impl = convertible_to<_Tp, bool>;
-
-template <class _Tp>
-concept __boolean_testable = __boolean_testable_impl<_Tp> && requires(_Tp&& __t) {
-  { !std::forward<_Tp>(__t) } -> __boolean_testable_impl;
-};
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_BOOLEAN_TESTABLE_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/class_or_enum.h b/third_party/libcxx/include/c++/v1/__concepts/class_or_enum.h
deleted file mode 100644
index 9fceed0..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/class_or_enum.h
+++ /dev/null
@@ -1,34 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_CLASS_OR_ENUM_H
-#define _LIBCPP___CONCEPTS_CLASS_OR_ENUM_H
-
-#include <__config>
-#include <__type_traits/is_class.h>
-#include <__type_traits/is_enum.h>
-#include <__type_traits/is_union.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// Whether a type is a class type or enumeration type according to the Core wording.
-
-template <class _Tp>
-concept __class_or_enum = is_class_v<_Tp> || is_union_v<_Tp> || is_enum_v<_Tp>;
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_CLASS_OR_ENUM_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/common_reference_with.h b/third_party/libcxx/include/c++/v1/__concepts/common_reference_with.h
deleted file mode 100644
index 4eb687e..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/common_reference_with.h
+++ /dev/null
@@ -1,36 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_COMMON_REFERENCE_WITH_H
-#define _LIBCPP___CONCEPTS_COMMON_REFERENCE_WITH_H
-
-#include <__concepts/convertible_to.h>
-#include <__concepts/same_as.h>
-#include <__config>
-#include <__type_traits/common_reference.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// [concept.commonref]
-
-template <class _Tp, class _Up>
-concept common_reference_with =
-    same_as<common_reference_t<_Tp, _Up>, common_reference_t<_Up, _Tp>> &&
-    convertible_to<_Tp, common_reference_t<_Tp, _Up>> && convertible_to<_Up, common_reference_t<_Tp, _Up>>;
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_COMMON_REFERENCE_WITH_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/common_with.h b/third_party/libcxx/include/c++/v1/__concepts/common_with.h
deleted file mode 100644
index 09082b2..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/common_with.h
+++ /dev/null
@@ -1,52 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_COMMON_WITH_H
-#define _LIBCPP___CONCEPTS_COMMON_WITH_H
-
-#include <__concepts/common_reference_with.h>
-#include <__concepts/same_as.h>
-#include <__config>
-#include <__type_traits/add_reference.h>
-#include <__type_traits/common_reference.h>
-#include <__type_traits/common_type.h>
-#include <__utility/declval.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// [concept.common]
-
-// clang-format off
-template <class _Tp, class _Up>
-concept common_with =
-    same_as<common_type_t<_Tp, _Up>, common_type_t<_Up, _Tp>> &&
-    requires {
-        static_cast<common_type_t<_Tp, _Up>>(std::declval<_Tp>());
-        static_cast<common_type_t<_Tp, _Up>>(std::declval<_Up>());
-    } &&
-    common_reference_with<
-        add_lvalue_reference_t<const _Tp>,
-        add_lvalue_reference_t<const _Up>> &&
-    common_reference_with<
-        add_lvalue_reference_t<common_type_t<_Tp, _Up>>,
-        common_reference_t<
-            add_lvalue_reference_t<const _Tp>,
-            add_lvalue_reference_t<const _Up>>>;
-// clang-format on
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_COMMON_WITH_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/comparison_common_type.h b/third_party/libcxx/include/c++/v1/__concepts/comparison_common_type.h
deleted file mode 100644
index 3f0d770..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/comparison_common_type.h
+++ /dev/null
@@ -1,40 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_COMPARISON_COMMON_TYPE_H
-#define _LIBCPP___CONCEPTS_COMPARISON_COMMON_TYPE_H
-
-#include <__concepts/convertible_to.h>
-#include <__concepts/same_as.h>
-#include <__config>
-#include <__type_traits/common_reference.h>
-#include <__type_traits/remove_cvref.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-template <class _Tp, class _Up, class _CommonRef = common_reference_t<const _Tp&, const _Up&>>
-concept __comparison_common_type_with_impl =
-    same_as<common_reference_t<const _Tp&, const _Up&>, common_reference_t<const _Up&, const _Tp&>> && requires {
-      requires convertible_to<const _Tp&, const _CommonRef&> || convertible_to<_Tp, const _CommonRef&>;
-      requires convertible_to<const _Up&, const _CommonRef&> || convertible_to<_Up, const _CommonRef&>;
-    };
-
-template <class _Tp, class _Up>
-concept __comparison_common_type_with = __comparison_common_type_with_impl<remove_cvref_t<_Tp>, remove_cvref_t<_Up>>;
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_COMPARISON_COMMON_TYPE_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/constructible.h b/third_party/libcxx/include/c++/v1/__concepts/constructible.h
deleted file mode 100644
index 835a444..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/constructible.h
+++ /dev/null
@@ -1,55 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_CONSTRUCTIBLE_H
-#define _LIBCPP___CONCEPTS_CONSTRUCTIBLE_H
-
-#include <__concepts/convertible_to.h>
-#include <__concepts/destructible.h>
-#include <__config>
-#include <__type_traits/is_constructible.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// [concept.constructible]
-template <class _Tp, class... _Args>
-concept constructible_from = destructible<_Tp> && is_constructible_v<_Tp, _Args...>;
-
-// [concept.default.init]
-
-template <class _Tp>
-concept __default_initializable = requires { ::new _Tp; };
-
-template <class _Tp>
-concept default_initializable = constructible_from<_Tp> && requires { _Tp{}; } && __default_initializable<_Tp>;
-
-// [concept.moveconstructible]
-template <class _Tp>
-concept move_constructible = constructible_from<_Tp, _Tp> && convertible_to<_Tp, _Tp>;
-
-// [concept.copyconstructible]
-// clang-format off
-template <class _Tp>
-concept copy_constructible =
-    move_constructible<_Tp> &&
-    constructible_from<_Tp, _Tp&> && convertible_to<_Tp&, _Tp> &&
-    constructible_from<_Tp, const _Tp&> && convertible_to<const _Tp&, _Tp> &&
-    constructible_from<_Tp, const _Tp> && convertible_to<const _Tp, _Tp>;
-// clang-format on
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_CONSTRUCTIBLE_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/convertible_to.h b/third_party/libcxx/include/c++/v1/__concepts/convertible_to.h
deleted file mode 100644
index 6d5b6c1..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/convertible_to.h
+++ /dev/null
@@ -1,33 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_CONVERTIBLE_TO_H
-#define _LIBCPP___CONCEPTS_CONVERTIBLE_TO_H
-
-#include <__config>
-#include <__type_traits/is_convertible.h>
-#include <__utility/declval.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// [concept.convertible]
-
-template <class _From, class _To>
-concept convertible_to = is_convertible_v<_From, _To> && requires { static_cast<_To>(std::declval<_From>()); };
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_CONVERTIBLE_TO_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/copyable.h b/third_party/libcxx/include/c++/v1/__concepts/copyable.h
deleted file mode 100644
index 2bf0ad4..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/copyable.h
+++ /dev/null
@@ -1,41 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_COPYABLE_H
-#define _LIBCPP___CONCEPTS_COPYABLE_H
-
-#include <__concepts/assignable.h>
-#include <__concepts/constructible.h>
-#include <__concepts/movable.h>
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// [concepts.object]
-
-// clang-format off
-template <class _Tp>
-concept copyable =
-    copy_constructible<_Tp> &&
-    movable<_Tp> &&
-    assignable_from<_Tp&, _Tp&> &&
-    assignable_from<_Tp&, const _Tp&> &&
-    assignable_from<_Tp&, const _Tp>;
-// clang-format on
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_COPYABLE_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/derived_from.h b/third_party/libcxx/include/c++/v1/__concepts/derived_from.h
deleted file mode 100644
index 9875fae..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/derived_from.h
+++ /dev/null
@@ -1,33 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_DERIVED_FROM_H
-#define _LIBCPP___CONCEPTS_DERIVED_FROM_H
-
-#include <__config>
-#include <__type_traits/is_base_of.h>
-#include <__type_traits/is_convertible.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// [concept.derived]
-
-template <class _Dp, class _Bp>
-concept derived_from = is_base_of_v<_Bp, _Dp> && is_convertible_v<const volatile _Dp*, const volatile _Bp*>;
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_DERIVED_FROM_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/destructible.h b/third_party/libcxx/include/c++/v1/__concepts/destructible.h
deleted file mode 100644
index 28b4b1b..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/destructible.h
+++ /dev/null
@@ -1,32 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_DESTRUCTIBLE_H
-#define _LIBCPP___CONCEPTS_DESTRUCTIBLE_H
-
-#include <__config>
-#include <__type_traits/is_nothrow_destructible.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// [concept.destructible]
-
-template <class _Tp>
-concept destructible = is_nothrow_destructible_v<_Tp>;
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_DESTRUCTIBLE_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/different_from.h b/third_party/libcxx/include/c++/v1/__concepts/different_from.h
deleted file mode 100644
index fd31f6e..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/different_from.h
+++ /dev/null
@@ -1,31 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_DIFFERENT_FROM_H
-#define _LIBCPP___CONCEPTS_DIFFERENT_FROM_H
-
-#include <__concepts/same_as.h>
-#include <__config>
-#include <__type_traits/remove_cvref.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-template <class _Tp, class _Up>
-concept __different_from = !same_as<remove_cvref_t<_Tp>, remove_cvref_t<_Up>>;
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_DIFFERENT_FROM_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/equality_comparable.h b/third_party/libcxx/include/c++/v1/__concepts/equality_comparable.h
deleted file mode 100644
index 56fc6f8..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/equality_comparable.h
+++ /dev/null
@@ -1,57 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_EQUALITY_COMPARABLE_H
-#define _LIBCPP___CONCEPTS_EQUALITY_COMPARABLE_H
-
-#include <__concepts/boolean_testable.h>
-#include <__concepts/common_reference_with.h>
-#include <__concepts/comparison_common_type.h>
-#include <__config>
-#include <__type_traits/common_reference.h>
-#include <__type_traits/make_const_lvalue_ref.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// [concept.equalitycomparable]
-
-template <class _Tp, class _Up>
-concept __weakly_equality_comparable_with =
-    requires(__make_const_lvalue_ref<_Tp> __t, __make_const_lvalue_ref<_Up> __u) {
-      { __t == __u } -> __boolean_testable;
-      { __t != __u } -> __boolean_testable;
-      { __u == __t } -> __boolean_testable;
-      { __u != __t } -> __boolean_testable;
-    };
-
-template <class _Tp>
-concept equality_comparable = __weakly_equality_comparable_with<_Tp, _Tp>;
-
-// clang-format off
-template <class _Tp, class _Up>
-concept equality_comparable_with =
-    equality_comparable<_Tp> && equality_comparable<_Up> &&
-    __comparison_common_type_with<_Tp, _Up> &&
-    equality_comparable<
-        common_reference_t<
-            __make_const_lvalue_ref<_Tp>,
-            __make_const_lvalue_ref<_Up>>> &&
-    __weakly_equality_comparable_with<_Tp, _Up>;
-// clang-format on
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_EQUALITY_COMPARABLE_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/invocable.h b/third_party/libcxx/include/c++/v1/__concepts/invocable.h
deleted file mode 100644
index 8a29398..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/invocable.h
+++ /dev/null
@@ -1,40 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_INVOCABLE_H
-#define _LIBCPP___CONCEPTS_INVOCABLE_H
-
-#include <__config>
-#include <__functional/invoke.h>
-#include <__utility/forward.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// [concept.invocable]
-
-template <class _Fn, class... _Args>
-concept invocable = requires(_Fn&& __fn, _Args&&... __args) {
-  std::invoke(std::forward<_Fn>(__fn), std::forward<_Args>(__args)...); // not required to be equality preserving
-};
-
-// [concept.regular.invocable]
-
-template <class _Fn, class... _Args>
-concept regular_invocable = invocable<_Fn, _Args...>;
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_INVOCABLE_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/movable.h b/third_party/libcxx/include/c++/v1/__concepts/movable.h
deleted file mode 100644
index bc5b9d7..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/movable.h
+++ /dev/null
@@ -1,35 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_MOVABLE_H
-#define _LIBCPP___CONCEPTS_MOVABLE_H
-
-#include <__concepts/assignable.h>
-#include <__concepts/constructible.h>
-#include <__concepts/swappable.h>
-#include <__config>
-#include <__type_traits/is_object.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// [concepts.object]
-
-template <class _Tp>
-concept movable = is_object_v<_Tp> && move_constructible<_Tp> && assignable_from<_Tp&, _Tp> && swappable<_Tp>;
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_MOVABLE_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/predicate.h b/third_party/libcxx/include/c++/v1/__concepts/predicate.h
deleted file mode 100644
index e0263a8..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/predicate.h
+++ /dev/null
@@ -1,34 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_PREDICATE_H
-#define _LIBCPP___CONCEPTS_PREDICATE_H
-
-#include <__concepts/boolean_testable.h>
-#include <__concepts/invocable.h>
-#include <__config>
-#include <__type_traits/invoke.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// [concept.predicate]
-
-template <class _Fn, class... _Args>
-concept predicate = regular_invocable<_Fn, _Args...> && __boolean_testable<invoke_result_t<_Fn, _Args...>>;
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_PREDICATE_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/regular.h b/third_party/libcxx/include/c++/v1/__concepts/regular.h
deleted file mode 100644
index 9f3d8bf..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/regular.h
+++ /dev/null
@@ -1,33 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_REGULAR_H
-#define _LIBCPP___CONCEPTS_REGULAR_H
-
-#include <__concepts/equality_comparable.h>
-#include <__concepts/semiregular.h>
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// [concept.object]
-
-template <class _Tp>
-concept regular = semiregular<_Tp> && equality_comparable<_Tp>;
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_REGULAR_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/relation.h b/third_party/libcxx/include/c++/v1/__concepts/relation.h
deleted file mode 100644
index 7545a7d..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/relation.h
+++ /dev/null
@@ -1,43 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_RELATION_H
-#define _LIBCPP___CONCEPTS_RELATION_H
-
-#include <__concepts/predicate.h>
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// [concept.relation]
-
-template <class _Rp, class _Tp, class _Up>
-concept relation =
-    predicate<_Rp, _Tp, _Tp> && predicate<_Rp, _Up, _Up> && predicate<_Rp, _Tp, _Up> && predicate<_Rp, _Up, _Tp>;
-
-// [concept.equiv]
-
-template <class _Rp, class _Tp, class _Up>
-concept equivalence_relation = relation<_Rp, _Tp, _Up>;
-
-// [concept.strictweakorder]
-
-template <class _Rp, class _Tp, class _Up>
-concept strict_weak_order = relation<_Rp, _Tp, _Up>;
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_RELATION_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/same_as.h b/third_party/libcxx/include/c++/v1/__concepts/same_as.h
deleted file mode 100644
index 4241131..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/same_as.h
+++ /dev/null
@@ -1,35 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_SAME_AS_H
-#define _LIBCPP___CONCEPTS_SAME_AS_H
-
-#include <__config>
-#include <__type_traits/is_same.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// [concept.same]
-
-template <class _Tp, class _Up>
-concept __same_as_impl = _IsSame<_Tp, _Up>::value;
-
-template <class _Tp, class _Up>
-concept same_as = __same_as_impl<_Tp, _Up> && __same_as_impl<_Up, _Tp>;
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_SAME_AS_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/semiregular.h b/third_party/libcxx/include/c++/v1/__concepts/semiregular.h
deleted file mode 100644
index 7a159d1..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/semiregular.h
+++ /dev/null
@@ -1,33 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_SEMIREGULAR_H
-#define _LIBCPP___CONCEPTS_SEMIREGULAR_H
-
-#include <__concepts/constructible.h>
-#include <__concepts/copyable.h>
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// [concept.object]
-
-template <class _Tp>
-concept semiregular = copyable<_Tp> && default_initializable<_Tp>;
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_SEMIREGULAR_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/swappable.h b/third_party/libcxx/include/c++/v1/__concepts/swappable.h
deleted file mode 100644
index c691d3a..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/swappable.h
+++ /dev/null
@@ -1,122 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_SWAPPABLE_H
-#define _LIBCPP___CONCEPTS_SWAPPABLE_H
-
-#include <__concepts/assignable.h>
-#include <__concepts/class_or_enum.h>
-#include <__concepts/common_reference_with.h>
-#include <__concepts/constructible.h>
-#include <__config>
-#include <__cstddef/size_t.h>
-#include <__type_traits/extent.h>
-#include <__type_traits/is_nothrow_assignable.h>
-#include <__type_traits/is_nothrow_constructible.h>
-#include <__type_traits/remove_cvref.h>
-#include <__utility/exchange.h>
-#include <__utility/forward.h>
-#include <__utility/move.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// [concept.swappable]
-
-namespace ranges {
-namespace __swap {
-
-template <class _Tp>
-void swap(_Tp&, _Tp&) = delete;
-
-// clang-format off
-template <class _Tp, class _Up>
-concept __unqualified_swappable_with =
-    (__class_or_enum<remove_cvref_t<_Tp>> || __class_or_enum<remove_cvref_t<_Up>>) &&
-    requires(_Tp&& __t, _Up&& __u) {
-        swap(std::forward<_Tp>(__t), std::forward<_Up>(__u));
-    };
-// clang-format on
-
-struct __fn;
-
-// clang-format off
-template <class _Tp, class _Up, size_t _Size>
-concept __swappable_arrays =
-    !__unqualified_swappable_with<_Tp (&)[_Size], _Up (&)[_Size]> &&
-    extent_v<_Tp> == extent_v<_Up> &&
-    requires(_Tp (&__t)[_Size], _Up (&__u)[_Size], const __fn& __swap) {
-        __swap(__t[0], __u[0]);
-    };
-// clang-format on
-
-template <class _Tp>
-concept __exchangeable =
-    !__unqualified_swappable_with<_Tp&, _Tp&> && move_constructible<_Tp> && assignable_from<_Tp&, _Tp>;
-
-struct __fn {
-  // 2.1   `S` is `(void)swap(E1, E2)`* if `E1` or `E2` has class or enumeration type and...
-  // *The name `swap` is used here unqualified.
-  template <class _Tp, class _Up>
-    requires __unqualified_swappable_with<_Tp, _Up>
-  _LIBCPP_HIDE_FROM_ABI constexpr void operator()(_Tp&& __t, _Up&& __u) const
-      noexcept(noexcept(swap(std::forward<_Tp>(__t), std::forward<_Up>(__u)))) {
-    swap(std::forward<_Tp>(__t), std::forward<_Up>(__u));
-  }
-
-  // 2.2   Otherwise, if `E1` and `E2` are lvalues of array types with equal extent and...
-  template <class _Tp, class _Up, size_t _Size>
-    requires __swappable_arrays<_Tp, _Up, _Size>
-  _LIBCPP_HIDE_FROM_ABI constexpr void operator()(_Tp (&__t)[_Size], _Up (&__u)[_Size]) const
-      noexcept(noexcept((*this)(*__t, *__u))) {
-    // TODO(cjdb): replace with `ranges::swap_ranges`.
-    for (size_t __i = 0; __i < _Size; ++__i) {
-      (*this)(__t[__i], __u[__i]);
-    }
-  }
-
-  // 2.3   Otherwise, if `E1` and `E2` are lvalues of the same type `T` that models...
-  template <__exchangeable _Tp>
-  _LIBCPP_HIDE_FROM_ABI constexpr void operator()(_Tp& __x, _Tp& __y) const
-      noexcept(is_nothrow_move_constructible_v<_Tp> && is_nothrow_move_assignable_v<_Tp>) {
-    __y = std::exchange(__x, std::move(__y));
-  }
-};
-} // namespace __swap
-
-inline namespace __cpo {
-inline constexpr auto swap = __swap::__fn{};
-} // namespace __cpo
-} // namespace ranges
-
-template <class _Tp>
-concept swappable = requires(_Tp& __a, _Tp& __b) { ranges::swap(__a, __b); };
-
-template <class _Tp, class _Up>
-concept swappable_with = common_reference_with<_Tp, _Up> && requires(_Tp&& __t, _Up&& __u) {
-  ranges::swap(std::forward<_Tp>(__t), std::forward<_Tp>(__t));
-  ranges::swap(std::forward<_Up>(__u), std::forward<_Up>(__u));
-  ranges::swap(std::forward<_Tp>(__t), std::forward<_Up>(__u));
-  ranges::swap(std::forward<_Up>(__u), std::forward<_Tp>(__t));
-};
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif // _LIBCPP___CONCEPTS_SWAPPABLE_H
diff --git a/third_party/libcxx/include/c++/v1/__concepts/totally_ordered.h b/third_party/libcxx/include/c++/v1/__concepts/totally_ordered.h
deleted file mode 100644
index 186c3b4..0000000
--- a/third_party/libcxx/include/c++/v1/__concepts/totally_ordered.h
+++ /dev/null
@@ -1,59 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___CONCEPTS_TOTALLY_ORDERED_H
-#define _LIBCPP___CONCEPTS_TOTALLY_ORDERED_H
-
-#include <__concepts/boolean_testable.h>
-#include <__concepts/equality_comparable.h>
-#include <__config>
-#include <__type_traits/common_reference.h>
-#include <__type_traits/make_const_lvalue_ref.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#  pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 20
-
-// [concept.totallyordered]
-
-template <class _Tp, class _Up>
-concept __partially_ordered_with = requires(__make_const_lvalue_ref<_Tp> __t, __make_const_lvalue_ref<_Up> __u) {
-  { __t < __u } -> __boolean_testable;
-  { __t > __u } -> __boolean_testable;
-  { __t <= __u } -> __boolean_testable;
-  { __t >= __u } -> __boolean_testable;
-  { __u < __t } -> __boolean_testable;
-  { __u > __t } -> __boolean_testable;
-  { __u <= __t } -> __boolean_testable;
-  { __u >= __t } -> __boolean_testable;
-};
-
-template <class _Tp>
-concept totally_ordered = equality_comparable<_Tp> && __partially_ordered_with<_Tp, _Tp>;
-
-// clang-format off
-template <class _Tp, class _Up>
-concept totally_ordered_with =
-    totally_ordered<_Tp> && totally_ordered<_Up> &&
-    equality_comparable_with<_Tp, _Up> &&
-    totally_ordered<
-        common_reference_t<
-            __make_const_lvalue_ref<_Tp>,
-            __make_const_lvalue_ref<_Up>>> &&
-    __partially_ordered_with<_Tp, _Up>;
-// clang-format on
-
-#endif // _LIBCPP_STD_VER >= 20
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP___CONCEPTS_TOTALLY_ORDERED_H