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Diffstat (limited to 'include/google/protobuf/explicitly_constructed.h')
| -rw-r--r-- | include/google/protobuf/explicitly_constructed.h | 97 |
1 files changed, 0 insertions, 97 deletions
diff --git a/include/google/protobuf/explicitly_constructed.h b/include/google/protobuf/explicitly_constructed.h deleted file mode 100644 index 174c59ab4b..0000000000 --- a/include/google/protobuf/explicitly_constructed.h +++ /dev/null @@ -1,97 +0,0 @@ -// Protocol Buffers - Google's data interchange format -// Copyright 2008 Google Inc. All rights reserved. -// https://developers.google.com/protocol-buffers/ -// -// Redistribution and use in source and binary forms, with or without -// modification, are permitted provided that the following conditions are -// met: -// -// * Redistributions of source code must retain the above copyright -// notice, this list of conditions and the following disclaimer. -// * Redistributions in binary form must reproduce the above -// copyright notice, this list of conditions and the following disclaimer -// in the documentation and/or other materials provided with the -// distribution. -// * Neither the name of Google Inc. nor the names of its -// contributors may be used to endorse or promote products derived from -// this software without specific prior written permission. -// -// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS -// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT -// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR -// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT -// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, -// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT -// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, -// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY -// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT -// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE -// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - -#ifndef GOOGLE_PROTOBUF_EXPLICITLY_CONSTRUCTED_H__ -#define GOOGLE_PROTOBUF_EXPLICITLY_CONSTRUCTED_H__ - -#include <stdint.h> - -#include <utility> - -#include <google/protobuf/stubs/logging.h> -#include <google/protobuf/stubs/common.h> - -// clang-format off -#include <google/protobuf/port_def.inc> -// clang-format on - -namespace google { -namespace protobuf { -namespace internal { - -// Wraps a variable whose constructor and destructor are explicitly -// called. It is particularly useful for a global variable, without its -// constructor and destructor run on start and end of the program lifetime. -// This circumvents the initial construction order fiasco, while keeping -// the address of the empty string a compile time constant. -// -// Pay special attention to the initialization state of the object. -// 1. The object is "uninitialized" to begin with. -// 2. Call Construct() or DefaultConstruct() only if the object is -// uninitialized. After the call, the object becomes "initialized". -// 3. Call get() and get_mutable() only if the object is initialized. -// 4. Call Destruct() only if the object is initialized. -// After the call, the object becomes uninitialized. -template <typename T, size_t min_align = 1> -class ExplicitlyConstructed { - public: - void DefaultConstruct() { new (&union_) T(); } - - template <typename... Args> - void Construct(Args&&... args) { - new (&union_) T(std::forward<Args>(args)...); - } - - void Destruct() { get_mutable()->~T(); } - - constexpr const T& get() const { return reinterpret_cast<const T&>(union_); } - T* get_mutable() { return reinterpret_cast<T*>(&union_); } - - private: - union AlignedUnion { - alignas(min_align > alignof(T) ? min_align - : alignof(T)) char space[sizeof(T)]; - int64_t align_to_int64; - void* align_to_ptr; - } union_; -}; - -// ArenaStringPtr compatible explicitly constructed string type. -// This empty string type is aligned with a minimum alignment of 8 bytes -// which is the minimum requirement of ArenaStringPtr -using ExplicitlyConstructedArenaString = ExplicitlyConstructed<std::string, 8>; - -} // namespace internal -} // namespace protobuf -} // namespace google - -#include <google/protobuf/port_undef.inc> - -#endif // GOOGLE_PROTOBUF_EXPLICITLY_CONSTRUCTED_H__ |