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b9a2658a3e
This patch implements the forwarding to frozen C++03 headers as discussed in https://discourse.llvm.org/t/rfc-freezing-c-03-headers-in-libc. In the RFC, we initially proposed selecting the right headers from the Clang driver, however consensus seemed to steer towards handling this in the library itself. This patch implements that direction. At a high level, the changes basically amount to making each public header look like this: ``` // inside <vector> #ifdef _LIBCPP_CXX03_LANG # include <__cxx03/vector> #else // normal <vector> content #endif ``` In most cases, public headers are simple umbrella headers so there isn't much code in the #else branch. In other cases, the #else branch contains the actual implementation of the header.
61 lines
1.7 KiB
C++
61 lines
1.7 KiB
C++
// -*- C++ -*-
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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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#ifndef _LIBCPP_EXPECTED
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#define _LIBCPP_EXPECTED
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/*
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Header <expected> synopsis
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namespace std {
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// [expected.unexpected], class template unexpected
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template<class E> class unexpected;
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// [expected.bad], class template bad_expected_access
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template<class E> class bad_expected_access;
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// [expected.bad.void], specialization for void
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template<> class bad_expected_access<void>;
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// in-place construction of unexpected values
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struct unexpect_t {
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explicit unexpect_t() = default;
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};
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inline constexpr unexpect_t unexpect{};
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// [expected.expected], class template expected
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template<class T, class E> class expected;
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// [expected.void], partial specialization of expected for void types
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template<class T, class E> requires is_void_v<T> class expected<T, E>;
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}
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*/
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#if __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
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# include <__cxx03/expected>
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#else
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# include <__config>
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# if _LIBCPP_STD_VER >= 23
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# include <__expected/bad_expected_access.h>
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# include <__expected/expected.h>
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# include <__expected/unexpect.h>
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# include <__expected/unexpected.h>
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# endif
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# include <version>
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# if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
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# pragma GCC system_header
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# endif
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#endif // __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
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#endif // _LIBCPP_EXPECTED
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