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-// Copyright 2017 The Abseil Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// -----------------------------------------------------------------------------
-// kConstInit
-// -----------------------------------------------------------------------------
-//
-// A constructor tag used to mark an object as safe for use as a global
-// variable, avoiding the usual lifetime issues that can affect globals.
-
-#ifndef ABSL_BASE_CONST_INIT_H_
-#define ABSL_BASE_CONST_INIT_H_
-
-#include "absl/base/config.h"
-
-// In general, objects with static storage duration (such as global variables)
-// can trigger tricky object lifetime situations.  Attempting to access them
-// from the constructors or destructors of other global objects can result in
-// undefined behavior, unless their constructors and destructors are designed
-// with this issue in mind.
-//
-// The normal way to deal with this issue in C++11 is to use constant
-// initialization and trivial destructors.
-//
-// Constant initialization is guaranteed to occur before any other code
-// executes.  Constructors that are declared 'constexpr' are eligible for
-// constant initialization.  You can annotate a variable declaration with the
-// ABSL_CONST_INIT macro to express this intent.  For compilers that support
-// it, this annotation will cause a compilation error for declarations that
-// aren't subject to constant initialization (perhaps because a runtime value
-// was passed as a constructor argument).
-//
-// On program shutdown, lifetime issues can be avoided on global objects by
-// ensuring that they contain  trivial destructors.  A class has a trivial
-// destructor unless it has a user-defined destructor, a virtual method or base
-// class, or a data member or base class with a non-trivial destructor of its
-// own.  Objects with static storage duration and a trivial destructor are not
-// cleaned up on program shutdown, and are thus safe to access from other code
-// running during shutdown.
-//
-// For a few core Abseil classes, we make a best effort to allow for safe global
-// instances, even though these classes have non-trivial destructors.  These
-// objects can be created with the absl::kConstInit tag.  For example:
-//   ABSL_CONST_INIT absl::Mutex global_mutex(absl::kConstInit);
-//
-// The line above declares a global variable of type absl::Mutex which can be
-// accessed at any point during startup or shutdown.  global_mutex's destructor
-// will still run, but will not invalidate the object.  Note that C++ specifies
-// that accessing an object after its destructor has run results in undefined
-// behavior, but this pattern works on the toolchains we support.
-//
-// The absl::kConstInit tag should only be used to define objects with static
-// or thread_local storage duration.
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-
-enum ConstInitType {
-  kConstInit,
-};
-
-ABSL_NAMESPACE_END
-}  // namespace absl
-
-#endif  // ABSL_BASE_CONST_INIT_H_