[UTIL] add status_macros.h; add template to strong integers

ortools/util/BUILD.bazel

@@ -446,3 +446,12 @@ cc_library(
         "@com_google_absl//absl/strings",
     ],
 )
+
+cc_library(
+    name = "status_macros",
+    hdrs = ["status_macros.h"],
+    deps = [
+        "//ortools/base:status_macros",
+        "@com_google_absl//absl/status",
+    ],
+)

ortools/util/status_macros.h

@@ -0,0 +1,45 @@
+// Copyright 2010-2021 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 OR_TOOLS_UTIL_STATUS_MACROS_H_
+#define OR_TOOLS_UTIL_STATUS_MACROS_H_
+
+#include "ortools/base/status_macros.h"
+
+// Executes an expression that returns an absl::StatusOr, extracting its value
+// into the variable defined by lhs or returning on error and enabling
+// decorating it with the third argument.
+//
+// Example: Assigning to an existing value
+//   ValueType value;
+//   OR_ASSIGN_OR_RETURN3(value, MaybeGetValue(arg), _ << "context");
+//   OR_ASSIGN_OR_RETURN3((auto [key, val]), MaybeGetValue(arg),
+//                        _ << "with key " << key);
+//
+// WARNING: OR_ASSIGN_OR_RETURN3 expands into multiple statements; it cannot be
+//  used in a single statement (e.g. as the body of an if statement without {})!
+//
+#define OR_ASSIGN_OR_RETURN3(lhs, rexpr, error_expression)                   \
+  OR_ASSIGN_OR_RETURN3_IMPL_(                                                \
+      STATUS_MACROS_IMPL_CONCAT_(_status_or_value, __COUNTER__), lhs, rexpr, \
+      error_expression)
+
+#define OR_ASSIGN_OR_RETURN3_IMPL_(statusor, lhs, rexpr, error_expression) \
+  auto statusor = (rexpr);                                                 \
+  if (!statusor.ok()) {                                                    \
+    ::util::StatusBuilder _(std::move(statusor).status());                 \
+    return (error_expression);                                             \
+  }                                                                        \
+  STATUS_MACROS_IMPL_UNPARENTHESIS(lhs) = std::move(statusor).value()
+
+#endif  // OR_TOOLS_UTIL_STATUS_MACROS_H_

ortools/util/strong_integers.h

@@ -220,6 +220,11 @@ class StrongInt64 {
 
   constexpr int64_t value() const { return value_; }
 
+  template <typename ValType>  // Needed for StrongVector.
+  constexpr ValType value() const {
+    return static_cast<ValType>(value_);
+  }
+
   INCREMENT_AND_DECREMENT_OPERATORS;
 
   constexpr const ThisType operator+() const { return ThisType(value_); }
@@ -277,6 +282,7 @@ std::ostream& operator<<(std::ostream& os,  // NOLINT
 STRONG_TYPE_ARITHMETIC_OP(StrongIndex, int, +);
 STRONG_TYPE_ARITHMETIC_OP(StrongIndex, int, -);
 STRONG_TYPE_ARITHMETIC_OP(StrongIndex, int, *);
+STRONG_TYPE_ARITHMETIC_OP(StrongIndex, int, %);
 
 STRONG_TYPE_ARITHMETIC_OP(StrongInt64, int64_t, +);
 STRONG_TYPE_ARITHMETIC_OP(StrongInt64, int64_t, -);