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September 29, 2021 15:56
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Status macros for absl::Status and absl::StatusOr<T>
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// 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. | |
// From: util/task/contrib/status_macros/status_macros.h | |
#ifndef GOOGLE_PROTOBUF_STUBS_STATUS_MACROS_H_ | |
#define GOOGLE_PROTOBUF_STUBS_STATUS_MACROS_H_ | |
//#include <google/protobuf/stubs/common.h> | |
#include "absl/status/status.h" | |
#include "absl/status/statusor.h" | |
namespace absl { | |
// Run a command that returns a util::Status. If the called code returns an | |
// error status, return that status up out of this method too. | |
// | |
// Example: | |
// RETURN_IF_ERROR(DoThings(4)); | |
#define RETURN_IF_ERROR(expr) \ | |
do { \ | |
/* Using _status below to avoid capture problems if expr is "status". */ \ | |
const PROTOBUF_NAMESPACE_ID::util::Status _status = (expr); \ | |
if (ABSL_PREDICT_FALSE(!_status.ok())) return _status; \ | |
} while (0) | |
// Internal helper for concatenating macro values. | |
#define STATUS_MACROS_CONCAT_NAME_INNER(x, y) x##y | |
#define STATUS_MACROS_CONCAT_NAME(x, y) STATUS_MACROS_CONCAT_NAME_INNER(x, y) | |
template<typename T> | |
Status DoAssignOrReturn(T& lhs, StatusOr<T> result) { | |
if (result.ok()) { | |
lhs = result.value(); | |
} | |
return result.status(); | |
} | |
#define ASSIGN_OR_RETURN_IMPL(status, lhs, rexpr) \ | |
absl::Status status = DoAssignOrReturn(lhs, (rexpr)); \ | |
if (ABSL_PREDICT_FALSE(!status.ok())) return status; | |
// Executes an expression that returns a util::StatusOr, extracting its value | |
// into the variable defined by lhs (or returning on error). | |
// | |
// Example: Assigning to an existing value | |
// ValueType value; | |
// ASSIGN_OR_RETURN(value, MaybeGetValue(arg)); | |
// | |
// WARNING: ASSIGN_OR_RETURN expands into multiple statements; it cannot be used | |
// in a single statement (e.g. as the body of an if statement without {})! | |
#define ASSIGN_OR_RETURN(lhs, rexpr) \ | |
ASSIGN_OR_RETURN_IMPL( \ | |
STATUS_MACROS_CONCAT_NAME(_status_or_value, __COUNTER__), lhs, rexpr); | |
} // namespace absl | |
#endif // GOOGLE_PROTOBUF_STUBS_STATUS_H_ |
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