sandboxed-api/sandboxed_api/util/status_internal.h

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// Copyright 2019 Google LLC
//
// 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
//
// http://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.
#ifndef THIRD_PARTY_SAPI_UTIL_STATUS_INTERNAL_H_
#define THIRD_PARTY_SAPI_UTIL_STATUS_INTERNAL_H_
#include <string>
#include <type_traits>
#include "absl/meta/type_traits.h"
namespace sapi {
namespace status_internal {
struct ErrorCodeHolder {
explicit ErrorCodeHolder(int code) : error_code(code) {}
template <typename EnumT,
typename E = typename absl::enable_if_t<std::is_enum<EnumT>::value>>
operator EnumT() { // NOLINT(runtime/explicit)
return static_cast<EnumT>(error_code);
}
int error_code;
};
template <typename StatusT>
struct status_type_traits {
private:
template <typename StatusU>
static auto CheckMinimalApi(StatusU* s, int* i, std::string* str, bool* b)
-> decltype(StatusU(ErrorCodeHolder(0), ""), *i = s->error_code(),
*str = s->error_message(), *b = s->ok(), std::true_type());
template <typename StatusU>
static auto CheckMinimalApi(...) -> decltype(std::false_type());
using minimal_api_type = decltype(CheckMinimalApi<StatusT>(
static_cast<StatusT*>(0), static_cast<int*>(0),
static_cast<std::string*>(0), static_cast<bool*>(0)));
public:
static constexpr bool is_status = minimal_api_type::value;
};
} // namespace status_internal
} // namespace sapi
#endif // THIRD_PARTY_SAPI_UTIL_STATUS_INTERNAL_H_