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// Copyright 2018 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.
//
// -----------------------------------------------------------------------------
// bad_variant_access.h
// -----------------------------------------------------------------------------
//
// This header file defines the `absl::bad_variant_access` type.
#ifndef ABSL_TYPES_BAD_VARIANT_ACCESS_H_
#define ABSL_TYPES_BAD_VARIANT_ACCESS_H_
#include <stdexcept>
#include "absl/base/config.h"
#ifdef ABSL_USES_STD_VARIANT
#include <variant>
namespace absl {
ABSL_NAMESPACE_BEGIN
using std::bad_variant_access;
ABSL_NAMESPACE_END
} // namespace absl
#else // ABSL_USES_STD_VARIANT
namespace absl {
ABSL_NAMESPACE_BEGIN
// -----------------------------------------------------------------------------
// bad_variant_access
// -----------------------------------------------------------------------------
//
// An `absl::bad_variant_access` type is an exception type that is thrown in
// the following cases:
//
// * Calling `absl::get(absl::variant) with an index or type that does not
// match the currently selected alternative type
// * Calling `absl::visit on an `absl::variant` that is in the
// `variant::valueless_by_exception` state.
//
// Example:
//
// absl::variant<int, std::string> v;
// v = 1;
// try {
// absl::get<std::string>(v);
// } catch(const absl::bad_variant_access& e) {
// std::cout << "Bad variant access: " << e.what() << '\n';
// }
class bad_variant_access : public std::exception {
public:
bad_variant_access() noexcept = default;
~bad_variant_access() override;
const char* what() const noexcept override;
};
namespace variant_internal {
[[noreturn]] ABSL_DLL void ThrowBadVariantAccess();
[[noreturn]] ABSL_DLL void Rethrow();
} // namespace variant_internal
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_USES_STD_VARIANT
#endif // ABSL_TYPES_BAD_VARIANT_ACCESS_H_