1 files changed, 81 insertions, 0 deletions
diff --git a/extern/draco/dracoenc/src/draco/core/status_or.h b/extern/draco/dracoenc/src/draco/core/status_or.h
new file mode 100644
index 00000000000..156b9bc02a7
--- /dev/null
+++ b/extern/draco/dracoenc/src/draco/core/status_or.h
@@ -0,0 +1,81 @@
+// Copyright 2017 The Draco 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
+//
+//      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 DRACO_CORE_STATUS_OR_H_
+#define DRACO_CORE_STATUS_OR_H_
+
+#include "draco/core/macros.h"
+#include "draco/core/status.h"
+
+namespace draco {
+
+// Class StatusOr is used to wrap a Status along with a value of a specified
+// type |T|. StatusOr is intended to be returned from functions in situations
+// where it is desirable to carry over more information about the potential
+// errors encountered during the function execution. If there are not errors,
+// the caller can simply use the return value, otherwise the Status object
+// provides more info about the encountered problem.
+template <class T>
+class StatusOr {
+ public:
+  StatusOr() {}
+  // Note: Constructors are intentionally not explicit to allow returning
+  // Status or the return value directly from functions.
+  StatusOr(const StatusOr &) = default;
+  StatusOr(StatusOr &&) = default;
+  StatusOr(const Status &status) : status_(status) {}
+  StatusOr(const T &value) : status_(OkStatus()), value_(value) {}
+  StatusOr(T &&value) : status_(OkStatus()), value_(std::move(value)) {}
+  StatusOr(const Status &status, const T &value)
+      : status_(status), value_(value) {}
+
+  const Status &status() const { return status_; }
+  const T &value() const & { return value_; }
+  const T &&value() const && { return std::move(value_); }
+  T &&value() && { return std::move(value_); }
+
+  // For consistency with existing Google StatusOr API we also include
+  // ValueOrDie() that currently returns the value().
+  const T &ValueOrDie() const & { return value(); }
+  T &&ValueOrDie() && { return std::move(value()); }
+
+  bool ok() const { return status_.ok(); }
+
+ private:
+  Status status_;
+  T value_;
+};
+
+// In case StatusOr<T> is ok(), this macro assigns value stored in StatusOr<T>
+// to |lhs|, otherwise it returns the error Status.
+//
+//   DRACO_ASSIGN_OR_RETURN(lhs, expression)
+//
+#define DRACO_ASSIGN_OR_RETURN(lhs, expression)                                \
+  DRACO_ASSIGN_OR_RETURN_IMPL_(DRACO_MACROS_IMPL_CONCAT_(_statusor, __LINE__), \
+                               lhs, expression, _status)
+
+// The actual implementation of the above macro.
+#define DRACO_ASSIGN_OR_RETURN_IMPL_(statusor, lhs, expression, error_expr) \
+  auto statusor = (expression);                                             \
+  if (!statusor.ok()) {                                                     \
+    auto _status = std::move(statusor.status());                            \
+    (void)_status; /* error_expression may not use it */                    \
+    return error_expr;                                                      \
+  }                                                                         \
+  lhs = std::move(statusor).value();
+
+}  // namespace draco
+
+#endif  // DRACO_CORE_STATUS_OR_H_