chromium/components/reporting/util/status_macros.h

// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_REPORTING_UTIL_STATUS_MACROS_H_
#define COMPONENTS_REPORTING_UTIL_STATUS_MACROS_H_

#include <optional>

#include "base/types/always_false.h"
#include "base/types/expected.h"
#include "components/reporting/util/status.h"
#include "components/reporting/util/statusor.h"

namespace reporting::internal {
// Helper functions for the macro RETURN_IF_ERROR_STATUS. Overloads of the
// following functions to return if the given status is OK. If yes, the return
// value is nullopt. If not, the desired return value is returned.
std::optional<Status> ShouldReturnStatus(const Status& status);
std::optional<Status> ShouldReturnStatus(Status&& status);
std::optional<base::unexpected<Status>> ShouldReturnStatus(
    const base::unexpected<Status>& status);
std::optional<base::unexpected<Status>> ShouldReturnStatus(
    base::unexpected<Status>&& status);

template <typename T>
void ShouldReturnStatus(T) { … }
}  // namespace reporting::internal

// Run a command that returns a Status.  If the called code returns an
// error status, return that status up out of this method too. The macro can
// also apply on `base::unexpected<Status>`, which is needed when the return
// type is StatusOr.
//
// Examples:
//
//   RETURN_IF_ERROR_STATUS(DoThing(4));  // Return type is Status
//
//   // Return type is StatusOr
//   RETURN_IF_ERROR_STATUS(base::unexpected(DoThing(4)));
#define RETURN_IF_ERROR_STATUS(expr) …

namespace reporting::internal {

// Helper functions and classes for the macros *_OK. Overloads of the
// following functions to return if the given Status or StatusOr is OK. The
// template classes are needed here because template functions can't be
// partially specialized.
template <typename T>
struct StatusOKHelper { … };

StatusOKHelper<StatusOr<T>>;

template <>
struct StatusOKHelper<Status> { … };

template <typename T>
bool IsOK(const T& s) { … }
}  // namespace reporting::internal

#define CHECK_OK(value) …
#define DCHECK_OK(value) …
#define ASSERT_OK(value) …
#define EXPECT_OK(value) …

#endif  // COMPONENTS_REPORTING_UTIL_STATUS_MACROS_H_