Nikolas Klauser e78f53d1e8
Reapply "[libc++][C++03] Copy the LLVM 19 headers (#108999)" (#112127)
This reverts commit 68c04b0ae62d8431d72d8b47fc13008002ee4387.

This disables the IWYU mapping that caused the failure, since
the headers aren't reachable for now.

This is the first part of the "Freezing C++03 headers" proposal
explained in
https://discourse.llvm.org/t/rfc-freezing-c-03-headers-in-libc/77319/58.

This patch mechanically copies the headers as of the LLVM 19.1 release
into a subdirectory of libc++ so that we can start using these headers
when building in C++03 mode. We are going to be backporting important
changes to that copy of the headers until the LLVM 21 release. After the
LLVM 21 release, only critical bugfixes will be fixed in the C++03 copy
of the headers.

This patch only performs a copy of the headers -- these headers are
still unused by the rest of the codebase.
2024-10-24 00:17:37 +02:00

199 lines
5.8 KiB
C++

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// 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_EXPERIMENTAL_MEMORY
#define _LIBCPP_EXPERIMENTAL_MEMORY
/*
experimental/memory synopsis
namespace std::experimental::inline fundamentals_v2 {
template <class W> class observer_ptr {
public:
using element_type = W;
using pointer = add_pointer_t<W>; // exposition-only
using reference = add_lvalue_reference_t<W>; // exposition-only
// default ctor
constexpr observer_ptr() noexcept;
// pointer-accepting ctors
constexpr observer_ptr(nullptr_t) noexcept;
constexpr explicit observer_ptr(pointer) noexcept;
// copying ctors (in addition to compiler-generated copy ctor)
template <class W2> constexpr observer_ptr(observer_ptr<W2>) noexcept;
// observers
constexpr pointer get() const noexcept;
constexpr reference operator*() const;
constexpr pointer operator->() const noexcept;
constexpr explicit operator bool() const noexcept;
// conversions
constexpr explicit operator pointer() const noexcept;
// modifiers
constexpr pointer release() noexcept;
constexpr void reset(pointer = nullptr) noexcept;
constexpr void swap(observer_ptr&) noexcept;
};
}
*/
#include <__functional/hash.h>
#include <__functional/operations.h>
#include <__type_traits/add_lvalue_reference.h>
#include <__type_traits/add_pointer.h>
#include <__type_traits/common_type.h>
#include <__type_traits/enable_if.h>
#include <__type_traits/is_convertible.h>
#include <cstddef>
#include <experimental/__config>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
#ifdef _LIBCPP_ENABLE_EXPERIMENTAL
_LIBCPP_BEGIN_NAMESPACE_LFTS_V2
# if _LIBCPP_STD_VER >= 17
template <class _Wp>
class observer_ptr {
public:
using element_type = _Wp;
// constructors
_LIBCPP_HIDE_FROM_ABI constexpr observer_ptr() noexcept : __ptr_(nullptr) {}
_LIBCPP_HIDE_FROM_ABI constexpr observer_ptr(nullptr_t) noexcept : __ptr_(nullptr) {}
_LIBCPP_HIDE_FROM_ABI constexpr explicit observer_ptr(element_type* __p) noexcept : __ptr_(__p) {}
template <class _W2, __enable_if_t<is_convertible<_W2*, _Wp*>::value, int> = 0>
_LIBCPP_HIDE_FROM_ABI constexpr observer_ptr(observer_ptr<_W2> __other) noexcept : __ptr_(__other.get()) {}
// observers
_LIBCPP_HIDE_FROM_ABI constexpr element_type* get() const noexcept { return __ptr_; }
_LIBCPP_HIDE_FROM_ABI constexpr add_lvalue_reference_t<_Wp> operator*() const { return *__ptr_; }
_LIBCPP_HIDE_FROM_ABI constexpr element_type* operator->() const noexcept { return __ptr_; }
_LIBCPP_HIDE_FROM_ABI constexpr explicit operator bool() const noexcept { return __ptr_ != nullptr; }
// conversions
_LIBCPP_HIDE_FROM_ABI constexpr explicit operator element_type*() const noexcept { return __ptr_; }
// modifiers
_LIBCPP_HIDE_FROM_ABI constexpr void reset(element_type* __p = nullptr) noexcept { __ptr_ = __p; }
_LIBCPP_HIDE_FROM_ABI constexpr void swap(observer_ptr& __other) noexcept {
observer_ptr __tmp = __other;
__other = *this;
*this = __tmp;
}
_LIBCPP_HIDE_FROM_ABI constexpr element_type* release() noexcept {
observer_ptr __p;
__p.swap(*this);
return __p.get();
}
private:
element_type* __ptr_;
};
// specializations
template <class _Wp>
_LIBCPP_HIDE_FROM_ABI constexpr void swap(observer_ptr<_Wp>& __a, observer_ptr<_Wp>& __b) noexcept {
__a.swap(__b);
}
template <class _Wp>
_LIBCPP_HIDE_FROM_ABI observer_ptr<_Wp> make_observer(_Wp* __ptr) noexcept {
return observer_ptr<_Wp>{__ptr};
}
template <class _W1, class _W2>
_LIBCPP_HIDE_FROM_ABI bool operator==(observer_ptr<_W1> __a, observer_ptr<_W2> __b) {
return __a.get() == __b.get();
}
template <class _W1, class _W2>
_LIBCPP_HIDE_FROM_ABI bool operator!=(observer_ptr<_W1> __a, observer_ptr<_W2> __b) {
return !(__a == __b);
}
template <class _Wp>
_LIBCPP_HIDE_FROM_ABI bool operator==(observer_ptr<_Wp> __p, nullptr_t) {
return !__p;
}
template <class _Wp>
_LIBCPP_HIDE_FROM_ABI bool operator==(nullptr_t, observer_ptr<_Wp> __p) {
return !__p;
}
template <class _Wp>
_LIBCPP_HIDE_FROM_ABI bool operator!=(observer_ptr<_Wp> __p, nullptr_t) {
return (bool)__p;
}
template <class _Wp>
_LIBCPP_HIDE_FROM_ABI bool operator!=(nullptr_t, observer_ptr<_Wp> __p) {
return (bool)__p;
}
template <class _W1, class _W2>
_LIBCPP_HIDE_FROM_ABI bool operator<(observer_ptr<_W1> __a, observer_ptr<_W2> __b) {
return std::less<typename std::common_type<_W1*, _W2*>::type>()(__a.get(), __b.get());
}
template <class _W1, class _W2>
_LIBCPP_HIDE_FROM_ABI bool operator>(observer_ptr<_W1> __a, observer_ptr<_W2> __b) {
return __b < __a;
}
template <class _W1, class _W2>
_LIBCPP_HIDE_FROM_ABI bool operator<=(observer_ptr<_W1> __a, observer_ptr<_W2> __b) {
return !(__a > __b);
}
template <class _W1, class _W2>
_LIBCPP_HIDE_FROM_ABI bool operator>=(observer_ptr<_W1> __a, observer_ptr<_W2> __b) {
return !(__a < __b);
}
# endif // _LIBCPP_STD_VER >= 17
_LIBCPP_END_NAMESPACE_LFTS_V2
_LIBCPP_BEGIN_NAMESPACE_STD
// hash
# if _LIBCPP_STD_VER >= 17
template <class _Tp>
struct hash<experimental::observer_ptr<_Tp>> {
_LIBCPP_HIDE_FROM_ABI size_t operator()(const experimental::observer_ptr<_Tp>& __ptr) const noexcept {
return hash<_Tp*>()(__ptr.get());
}
};
# endif // _LIBCPP_STD_VER >= 17
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP_ENABLE_EXPERIMENTAL
#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
# include <limits>
#endif
#endif /* _LIBCPP_EXPERIMENTAL_MEMORY */