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/*
* Copyright 2019 Google Inc.
* 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.
*/
#ifndef UTIL_STATUS_MACROS_H_
#define UTIL_STATUS_MACROS_H_
#include "absl/base/port.h"
#include "absl/status/status.h"
#include "absl/status/statusor.h"
// Helper macro that checks if the right hand side (rexpression) evaluates to a
// StatusOr with Status OK, and if so assigns the value to the value on the left
// hand side (lhs), otherwise returns the error status. Example:
// ASSIGN_OR_RETURN(lhs, rexpression);
#ifndef ASSIGN_OR_RETURN
#define ASSIGN_OR_RETURN(lhs, rexpr) \
PRIVATE_JOIN_AND_COMPUTE_ASSIGN_OR_RETURN_IMPL_( \
PRIVATE_JOIN_AND_COMPUTE_STATUS_MACROS_IMPL_CONCAT_(status_or_value, \
__LINE__), \
lhs, rexpr)
// Internal helper.
#define PRIVATE_JOIN_AND_COMPUTE_ASSIGN_OR_RETURN_IMPL_(statusor, lhs, rexpr) \
auto statusor = (rexpr); \
if (ABSL_PREDICT_FALSE(!statusor.ok())) { \
return std::move(statusor).status(); \
} \
lhs = *std::move(statusor)
#endif // ASSIGN_OR_RETURN
// Helper macro that checks if the given expression evaluates to a
// Status with Status OK. If not, returns the error status. Example:
// RETURN_IF_ERROR(expression);
#ifndef RETURN_IF_ERROR
#define RETURN_IF_ERROR(expr) \
PRIVATE_JOIN_AND_COMPUTE_RETURN_IF_ERROR_IMPL_( \
PRIVATE_JOIN_AND_COMPUTE_STATUS_MACROS_IMPL_CONCAT_(status_value, \
__LINE__), \
expr)
// Internal helper.
#define PRIVATE_JOIN_AND_COMPUTE_RETURN_IF_ERROR_IMPL_(status, expr) \
auto status = (expr); \
if (ABSL_PREDICT_FALSE(!status.ok())) { \
return status; \
}
#endif // RETURN_IF_ERROR
// Internal helper for concatenating macro values.
#define PRIVATE_JOIN_AND_COMPUTE_STATUS_MACROS_IMPL_CONCAT_INNER_(x, y) x##y
#define PRIVATE_JOIN_AND_COMPUTE_STATUS_MACROS_IMPL_CONCAT_(x, y) \
PRIVATE_JOIN_AND_COMPUTE_STATUS_MACROS_IMPL_CONCAT_INNER_(x, y)
#endif // UTIL_STATUS_MACROS_H_
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