diff --git a/ortools/base/BUILD.bazel b/ortools/base/BUILD.bazel
index dab2753916..df1f2d88e1 100644
--- a/ortools/base/BUILD.bazel
+++ b/ortools/base/BUILD.bazel
@@ -19,7 +19,6 @@ package(default_visibility = ["//visibility:public"])
 filegroup(
     name = "base_swig",
     srcs = ["base.i"],
-    visibility = ["//visibility:public"],
 )
 
 cc_library(
@@ -33,7 +32,6 @@ cc_library(
         "adjustable_priority_queue.h",
         "adjustable_priority_queue-inl.h",
     ],
-    deps = [":base"],
 )
 
 cc_library(
@@ -64,21 +62,13 @@ cc_library(
         ":commandlineflags",
         ":logging",
         ":types",
-        "@abseil-cpp//absl/base",
-        "@abseil-cpp//absl/container:flat_hash_map",
-        "@abseil-cpp//absl/container:flat_hash_set",
-        "@abseil-cpp//absl/container:node_hash_map",
-        "@abseil-cpp//absl/container:node_hash_set",
         "@abseil-cpp//absl/flags:flag",
         "@abseil-cpp//absl/flags:parse",
         "@abseil-cpp//absl/flags:usage",
         "@abseil-cpp//absl/log",
-        "@abseil-cpp//absl/log:check",
-        "@abseil-cpp//absl/log:die_if_null",
-        "@abseil-cpp//absl/log:globals",
         "@abseil-cpp//absl/log:initialize",
         "@abseil-cpp//absl/strings",
-        "@abseil-cpp//absl/synchronization",
+        "@abseil-cpp//absl/strings:string_view",
     ],
 )
 
@@ -108,7 +98,6 @@ cc_library(
     name = "constant_divisor",
     srcs = ["constant_divisor.cc"],
     hdrs = ["constant_divisor.h"],
-    visibility = ["//visibility:public"],
     deps = [
         "@abseil-cpp//absl/log:check",
         "@abseil-cpp//absl/numeric:int128",
@@ -120,19 +109,18 @@ cc_test(
     srcs = ["constant_divisor_test.cc"],
     deps = [
         ":constant_divisor",
+        "//ortools/base:gmock_main",
         "@abseil-cpp//absl/flags:flag",
         "@abseil-cpp//absl/random",
         "@abseil-cpp//absl/random:bit_gen_ref",
         "@abseil-cpp//absl/random:distributions",
         "@google_benchmark//:benchmark",
-        "@googletest//:gtest_main",
     ],
 )
 
 cc_library(
     name = "container_logging",
     hdrs = ["container_logging.h"],
-    deps = [":base"],
 )
 
 cc_library(
@@ -143,7 +131,6 @@ cc_library(
         "//conditions:default": [],
     }),
     deps = [
-        ":strong_int",
         ":strong_vector",
         "@abseil-cpp//absl/container:inlined_vector",
     ],
@@ -161,17 +148,10 @@ cc_test(
         ":dump_vars",
         ":strong_int",
         ":strong_vector",
-        "@abseil-cpp//absl/strings",
         "@googletest//:gtest_main",
     ],
 )
 
-cc_library(
-    name = "flags",
-    hdrs = ["flags.h"],
-    deps = ["@abseil-cpp//absl/flags:flag"],
-)
-
 cc_library(
     name = "file",
     srcs = [
@@ -189,6 +169,7 @@ cc_library(
         "@abseil-cpp//absl/log",
         "@abseil-cpp//absl/log:check",
         "@abseil-cpp//absl/status",
+        "@abseil-cpp//absl/status:statusor",
         "@abseil-cpp//absl/strings",
         "@bzip2//:bz2",
         "@protobuf",
@@ -221,10 +202,9 @@ cc_library(
     srcs = ["gzipfile.cc"],
     hdrs = ["gzipfile.h"],
     deps = [
-        ":base",
         ":file",
-        ":path",
-        "@abseil-cpp//absl/strings",
+        ":logging",
+        "@abseil-cpp//absl/strings:string_view",
         "@zlib",
     ],
 )
@@ -233,7 +213,9 @@ cc_library(
     name = "gzipstring",
     hdrs = ["gzipstring.h"],
     deps = [
-        ":base",
+        ":logging",
+        "@abseil-cpp//absl/log",
+        "@abseil-cpp//absl/strings:string_view",
         "@zlib",
     ],
 )
@@ -242,41 +224,40 @@ cc_library(
     name = "hash",
     srcs = ["hash.cc"],
     hdrs = ["hash.h"],
-    deps = ["@abseil-cpp//absl/strings"],
 )
 
 cc_library(
     name = "int_type",
     hdrs = ["int_type.h"],
-    deps = [":base"],
+    deps = [
+        "@abseil-cpp//absl/base:core_headers",
+        "@abseil-cpp//absl/strings:string_view",
+    ],
 )
 
 cc_library(
     name = "intops",
     hdrs = ["strong_int.h"],
     deps = [
-        ":int_type",
-        "@abseil-cpp//absl/log:absl_log",
-        "@abseil-cpp//absl/numeric:int128",
+        "@abseil-cpp//absl/meta:type_traits",
         "@abseil-cpp//absl/strings",
         "@abseil-cpp//absl/strings:str_format",
+        "@abseil-cpp//absl/strings:string_view",
     ],
 )
 
 cc_library(
     name = "iterator_adaptors",
     hdrs = ["iterator_adaptors.h"],
-    deps = [":base"],
 )
 
 cc_library(
     name = "linked_hash_map",
     hdrs = ["linked_hash_map.h"],
     deps = [
-        ":base",
-        ":logging",
+        "//ortools/base",
         "@abseil-cpp//absl/container:common",
-        "@abseil-cpp//absl/container:flat_hash_map",
+        "@abseil-cpp//absl/container:flat_hash_set",
     ],
 )
 
@@ -286,32 +267,38 @@ cc_library(
     hdrs = ["logging.h"],
     deps = [
         ":base_export",
+        "@abseil-cpp//absl/base:core_headers",
         "@abseil-cpp//absl/base:log_severity",
         "@abseil-cpp//absl/flags:flag",
         "@abseil-cpp//absl/flags:usage",
         "@abseil-cpp//absl/log",
         "@abseil-cpp//absl/log:check",
         "@abseil-cpp//absl/log:die_if_null",
-        "@abseil-cpp//absl/log:flags",
         "@abseil-cpp//absl/log:globals",
         "@abseil-cpp//absl/log:initialize",
+        "@abseil-cpp//absl/log:vlog_is_on",
         "@abseil-cpp//absl/memory",
         "@abseil-cpp//absl/status",
         "@abseil-cpp//absl/strings",
+        "@abseil-cpp//absl/strings:string_view",
     ],
 )
 
 cc_library(
     name = "map_util",
     hdrs = ["map_util.h"],
-    deps = [":base"],
+    deps = ["//ortools/base:logging"],
 )
 
 cc_library(
     name = "mathutil",
     srcs = ["mathutil.cc"],
     hdrs = ["mathutil.h"],
-    deps = [":base"],
+    deps = [
+        "//ortools/base:logging",
+        "@abseil-cpp//absl/base",
+        "@abseil-cpp//absl/log:check",
+    ],
 )
 
 cc_library(
@@ -322,17 +309,12 @@ cc_library(
 cc_library(
     name = "memutil",
     hdrs = ["memutil.h"],
-    deps = ["@abseil-cpp//absl/strings"],
 )
 
 cc_library(
     name = "murmur",
     hdrs = ["murmur.h"],
-    deps = [
-        ":base",
-        ":hash",
-        "@abseil-cpp//absl/strings",
-    ],
+    deps = ["//ortools/base:hash"],
 )
 
 cc_library(
@@ -356,6 +338,8 @@ cc_library(
     deps = [
         "//ortools/base:status_macros",
         "@abseil-cpp//absl/log:check",
+        "@abseil-cpp//absl/status",
+        "@abseil-cpp//absl/strings:string_view",
         "@protobuf",
     ],
 )
@@ -365,8 +349,7 @@ cc_library(
     testonly = True,
     hdrs = ["parse_test_proto.h"],
     deps = [
-        ":gmock",
-        "@abseil-cpp//absl/log:check",
+        "//ortools/base:gmock",
         "@protobuf",
     ],
 )
@@ -376,18 +359,23 @@ cc_library(
     srcs = ["path.cc"],
     hdrs = ["path.h"],
     deps = [
-        ":base",
         "@abseil-cpp//absl/strings",
+        "@abseil-cpp//absl/strings:string_view",
     ],
 )
 
 cc_library(
     name = "protobuf_util",
     hdrs = ["protobuf_util.h"],
+    deps = [
+        "@abseil-cpp//absl/log:check",
+        "@protobuf",
+    ],
 )
 
 cc_library(
     name = "protocol-buffer-matchers",
+    testonly = True,
     srcs = ["protocol-buffer-matchers.cc"],
     hdrs = ["protocol-buffer-matchers.h"],
     deps = [
@@ -402,9 +390,9 @@ cc_library(
     name = "protoutil",
     hdrs = ["protoutil.h"],
     deps = [
-        ":timer",
         "@abseil-cpp//absl/status",
         "@abseil-cpp//absl/status:statusor",
+        "@abseil-cpp//absl/time",
         "@protobuf",
     ],
 )
@@ -412,10 +400,7 @@ cc_library(
 cc_library(
     name = "proto_enum_utils",
     hdrs = ["proto_enum_utils.h"],
-    deps = [
-        "@abseil-cpp//absl/types:span",
-        "@protobuf",
-    ],
+    deps = ["@protobuf"],
 )
 
 cc_library(
@@ -423,12 +408,9 @@ cc_library(
     srcs = ["recordio.cc"],
     hdrs = ["recordio.h"],
     deps = [
-        ":base",
         ":file",
-        ":logging",
-        "@abseil-cpp//absl/status:statusor",
-        "@abseil-cpp//absl/strings",
-        "@protobuf",
+        "@abseil-cpp//absl/log",
+        "@abseil-cpp//absl/log:check",
         "@zlib",
     ],
 )
@@ -443,7 +425,6 @@ cc_library(
     name = "status_builder",
     hdrs = ["status_builder.h"],
     deps = [
-        ":base",
         "@abseil-cpp//absl/status",
         "@abseil-cpp//absl/strings",
     ],
@@ -453,7 +434,6 @@ cc_library(
     name = "status_macros",
     hdrs = ["status_macros.h"],
     deps = [
-        ":base",
         ":status_builder",
         "@abseil-cpp//absl/status",
         "@abseil-cpp//absl/status:statusor",
@@ -463,7 +443,10 @@ cc_library(
 cc_library(
     name = "stl_util",
     hdrs = ["stl_util.h"],
-    deps = [":base"],
+    deps = [
+        "@abseil-cpp//absl/base:core_headers",
+        "@abseil-cpp//absl/meta:type_traits",
+    ],
 )
 
 cc_library(
@@ -489,16 +472,15 @@ cc_test(
     timeout = "long",
     srcs = ["strong_int_test.cc"],
     deps = [
-        ":gmock",
         ":logging",
         ":strong_int",
+        "//ortools/base:gmock_main",
         "@abseil-cpp//absl/container:node_hash_map",
         "@abseil-cpp//absl/flags:marshalling",
         "@abseil-cpp//absl/hash:hash_testing",
         "@abseil-cpp//absl/numeric:int128",
         "@abseil-cpp//absl/strings",
         "@abseil-cpp//absl/strings:str_format",
-        "@googletest//:gtest_main",
     ],
 )
 
@@ -506,8 +488,8 @@ cc_library(
     name = "strong_vector",
     hdrs = ["strong_vector.h"],
     deps = [
-        ":base",
         ":intops",
+        "//ortools/base:logging",
     ],
 )
 
@@ -516,16 +498,27 @@ cc_library(
     srcs = ["strtoint.cc"],
     hdrs = ["strtoint.h"],
     deps = [
+        "@abseil-cpp//absl/base:core_headers",
         "@abseil-cpp//absl/log:check",
         "@abseil-cpp//absl/strings",
     ],
 )
 
+cc_test(
+    name = "strtoint_test",
+    size = "small",
+    srcs = ["strtoint_test.cc"],
+    deps = [
+        ":strtoint",
+        "//ortools/base:gmock_main",
+        "//ortools/base:types",
+    ],
+)
+
 cc_library(
     name = "sysinfo",
     srcs = ["sysinfo.cc"],
     hdrs = ["sysinfo.h"],
-    deps = ["@abseil-cpp//absl/strings"],
 )
 
 cc_library(
@@ -533,10 +526,10 @@ cc_library(
     srcs = ["temp_file.cc"],
     hdrs = ["temp_file.h"],
     deps = [
-        ":base",
-        ":file",
-        "@abseil-cpp//absl/status",
+        "//ortools/base:logging",
+        "@abseil-cpp//absl/status:statusor",
         "@abseil-cpp//absl/strings",
+        "@abseil-cpp//absl/strings:str_format",
         "@abseil-cpp//absl/time",
     ],
 )
@@ -551,6 +544,7 @@ cc_library(
         "@abseil-cpp//absl/log:check",
         "@abseil-cpp//absl/status",
         "@abseil-cpp//absl/strings",
+        "@abseil-cpp//absl/strings:string_view",
         "@abseil-cpp//absl/time",
     ],
 )
@@ -561,7 +555,7 @@ cc_library(
     hdrs = ["threadpool.h"],
     deps = [
         "@abseil-cpp//absl/log:check",
-        "@abseil-cpp//absl/synchronization",
+        "@abseil-cpp//absl/strings",
     ],
 )
 
@@ -578,6 +572,7 @@ cc_library(
 cc_library(
     name = "top_n",
     hdrs = ["top_n.h"],
+    deps = [":logging"],
 )
 
 cc_library(
@@ -591,9 +586,8 @@ cc_library(
     hdrs = ["zipfile.h"],
     deps = [
         ":file",
-        ":path",
-        ":stl_util",
-        "@abseil-cpp//absl/strings",
+        ":logging",
+        "@abseil-cpp//absl/strings:string_view",
         "@zlib",
     ],
 )
diff --git a/ortools/base/accurate_sum_test.cc b/ortools/base/accurate_sum_test.cc
new file mode 100644
index 0000000000..830eca4c23
--- /dev/null
+++ b/ortools/base/accurate_sum_test.cc
@@ -0,0 +1,51 @@
+// Copyright 2010-2025 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.
+
+#include "ortools/base/accurate_sum.h"
+
+#include <cmath>
+#include <random>
+#include <vector>
+
+#include "absl/random/random.h"
+#include "gtest/gtest.h"
+#include "ortools/base/accurate_sum.h"
+
+namespace {
+
+TEST(AccurateSumTest, ExactConsistencyWithUtilMath) {
+  std::vector<double> data;
+  {
+    std::mt19937 random(12345);
+    const int kNumNumbers = 1000000;
+    data.assign(kNumNumbers, 0.0);
+    for (int i = 0; i < kNumNumbers; ++i) {
+      const double abs_value = exp2(absl::Uniform<double>(random, -100, 100.0));
+      data[i] = absl::Bernoulli(random, 1.0 / 2) ? abs_value : -abs_value;
+    }
+  }
+  operations_research::AccurateSum<double> forked_sum;
+  AccurateSum<double> reference_sum;
+  // Runtime: August 2013, fastbuild, forge: 4 seconds.
+  const int kNumPasses = 100;
+  for (int i = 0; i < kNumPasses; ++i) {
+    for (const double v : data) {
+      forked_sum.Add(v);
+      reference_sum.Add(v);
+    }
+  }
+  // We *do* mean to expect a rigorous floating-point equality.
+  EXPECT_EQ(reference_sum.Value(), forked_sum.Value());
+}
+
+}  // namespace
diff --git a/ortools/base/container_logging.h b/ortools/base/container_logging.h
index f6d5831bef..63fb113781 100644
--- a/ortools/base/container_logging.h
+++ b/ortools/base/container_logging.h
@@ -41,8 +41,6 @@
 #include <string>
 #include <type_traits>
 
-#include "absl/base/port.h"
-
 namespace gtl {
 
 // Several policy classes below determine how LogRangeToStream will
diff --git a/ortools/base/dump_vars_test.cc b/ortools/base/dump_vars_test.cc
index 81b4e5ae8d..57697d6188 100644
--- a/ortools/base/dump_vars_test.cc
+++ b/ortools/base/dump_vars_test.cc
@@ -14,9 +14,9 @@
 #include "ortools/base/dump_vars.h"
 
 #include <optional>
-#include <ostream>
 #include <sstream>
 #include <string>
+#include <string_view>
 #include <utility>
 #include <vector>
 
diff --git a/ortools/base/filesystem.cc b/ortools/base/filesystem.cc
index 5fdcab30c1..a45dc9c113 100644
--- a/ortools/base/filesystem.cc
+++ b/ortools/base/filesystem.cc
@@ -13,11 +13,18 @@
 
 #include "ortools/base/filesystem.h"
 
+#include <algorithm>
+#include <exception>   // IWYU pragma: keep
 #include <filesystem>  // NOLINT(build/c++17)
 #include <regex>       // NOLINT
+#include <string>
+#include <string_view>
+#include <system_error>  // NOLINT
+#include <vector>
 
 #include "absl/status/status.h"
 #include "absl/strings/str_replace.h"
+#include "ortools/base/file.h"
 
 namespace fs = std::filesystem;
 
diff --git a/ortools/base/linked_hash_map_test.cc b/ortools/base/linked_hash_map_test.cc
new file mode 100644
index 0000000000..28b50c727c
--- /dev/null
+++ b/ortools/base/linked_hash_map_test.cc
@@ -0,0 +1,732 @@
+// Copyright 2010-2025 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.
+
+// Tests linked_hash_map.
+//
+// This test was forked from ortools/base/linked_hash_map_test.cc on Feb 25,
+// 2021. Some tests were deleted as they depended on code not visible from here.
+
+#include "ortools/base/linked_hash_map.h"
+
+#include <memory>
+#include <string>
+#include <tuple>
+#include <utility>
+#include <vector>
+
+#include "absl/container/internal/unordered_map_constructor_test.h"
+#include "absl/container/internal/unordered_map_lookup_test.h"
+#include "absl/container/internal/unordered_map_members_test.h"
+#include "absl/container/internal/unordered_map_modifiers_test.h"
+#include "absl/memory/memory.h"
+#include "absl/types/any.h"
+#include "gtest/gtest.h"
+#include "ortools/base/gmock.h"
+#include "util/gtl/map_util_test.h"
+
+namespace gtl {
+namespace {
+
+// Need to import the namespace to bring the names generated by GoogleTest for
+// the typed test suite.
+using namespace absl::container_internal;  // NOLINT
+
+using ::absl::container_internal::hash_internal::Enum;
+using ::absl::container_internal::hash_internal::EnumClass;
+
+template <class K, class V>
+using Map = linked_hash_map<K, V, StatefulTestingHash, StatefulTestingEqual,
+                            Alloc<std::pair<const K, V>>>;
+
+static_assert(!std::is_standard_layout<NonStandardLayout>(), "");
+
+using MapTypes =
+    ::testing::Types<Map<int, int>, Map<std::string, int>,
+                     Map<Enum, std::string>, Map<EnumClass, int>,
+                     Map<int, NonStandardLayout>, Map<NonStandardLayout, int>>;
+
+INSTANTIATE_TYPED_TEST_SUITE_P(LinkedHashMap, ConstructorTest, MapTypes);
+INSTANTIATE_TYPED_TEST_SUITE_P(LinkedHashMap, LookupTest, MapTypes);
+INSTANTIATE_TYPED_TEST_SUITE_P(LinkedHashMap, MembersTest, MapTypes);
+INSTANTIATE_TYPED_TEST_SUITE_P(LinkedHashMap, ModifiersTest, MapTypes);
+
+using ::testing::ElementsAre;
+using ::testing::Pair;
+using ::testing::Pointee;
+
+// Tests that the range constructor works.
+TEST(LinkedHashMapTest, RangeConstruct) {
+  const std::pair<int, int> items[] = {{1, 2}, {2, 3}, {3, 4}};
+  EXPECT_THAT((linked_hash_map<int, int>(std::begin(items), std::end(items))),
+              ElementsAre(Pair(1, 2), Pair(2, 3), Pair(3, 4)));
+}
+
+// Tests that copying works.
+TEST(LinkedHashMapTest, Copy) {
+  linked_hash_map<int, int> m{{2, 12}, {3, 13}};
+  // NOLINTNEXTLINE(performance-unnecessary-copy-initialization)
+  auto copy = m;
+
+  EXPECT_TRUE(copy.contains(2));
+  auto found = copy.find(2);
+  ASSERT_TRUE(found != copy.end());
+  for (auto iter = copy.begin(); iter != copy.end(); ++iter) {
+    if (iter == found) return;
+  }
+  FAIL() << "Copied map's find method returned an invalid iterator.";
+}
+
+// Tests that assignment works.
+TEST(LinkedHashMapTest, Assign) {
+  linked_hash_map<int, int> m{{2, 12}, {3, 13}};
+  linked_hash_map<int, int> n{{4, 14}};
+
+  n = m;
+  EXPECT_TRUE(n.contains(2));
+  auto found = n.find(2);
+  ASSERT_TRUE(found != n.end());
+  for (auto iter = n.begin(); iter != n.end(); ++iter) {
+    if (iter == found) return;
+  }
+  FAIL() << "Assigned map's find method returned an invalid iterator.";
+}
+
+// Tests that move constructor works.
+TEST(LinkedHashMapTest, Move) {
+  // Use unique_ptr as an example of a non-copyable type.
+  linked_hash_map<int, std::unique_ptr<int>> m;
+  m[2] = std::make_unique<int>(12);
+  m[3] = std::make_unique<int>(13);
+  linked_hash_map<int, std::unique_ptr<int>> n = std::move(m);
+  EXPECT_THAT(n, ElementsAre(Pair(2, Pointee(12)), Pair(3, Pointee(13))));
+}
+
+TEST(LinkedHashMapTest, CanInsertMoveOnly) {
+  linked_hash_map<int, std::unique_ptr<int>> m;
+  struct Data {
+    int k, v;
+  };
+  const Data data[] = {{1, 123}, {3, 345}, {2, 234}, {4, 456}};
+  for (const auto& kv : data)
+    m.insert({kv.k, std::make_unique<int>(int{kv.v})});
+  EXPECT_TRUE(m.contains(2));
+  auto found = m.find(2);
+  ASSERT_TRUE(found != m.end());
+  EXPECT_EQ(234, *found->second);
+}
+
+TEST(LinkedHashMapTest, CanEmplaceMoveOnly) {
+  linked_hash_map<int, std::unique_ptr<int>> m;
+  struct Data {
+    int k, v;
+  };
+  const Data data[] = {{1, 123}, {3, 345}, {2, 234}, {4, 456}};
+  for (const auto& kv : data) {
+    m.emplace(std::piecewise_construct, std::make_tuple(kv.k),
+              std::make_tuple(new int{kv.v}));
+  }
+  EXPECT_TRUE(m.contains(2));
+  auto found = m.find(2);
+  ASSERT_TRUE(found != m.end());
+  EXPECT_EQ(234, *found->second);
+}
+
+struct NoCopy {
+  explicit NoCopy(int x) : x(x) {}
+  NoCopy(const NoCopy&) = delete;
+  NoCopy& operator=(const NoCopy&) = delete;
+  NoCopy(NoCopy&&) = delete;
+  NoCopy& operator=(NoCopy&&) = delete;
+  int x;
+};
+
+TEST(LinkedHashMapTest, CanEmplaceNoMoveNoCopy) {
+  linked_hash_map<int, NoCopy> m;
+  struct Data {
+    int k, v;
+  };
+  const Data data[] = {{1, 123}, {3, 345}, {2, 234}, {4, 456}};
+  for (const auto& kv : data) {
+    m.emplace(std::piecewise_construct, std::make_tuple(kv.k),
+              std::make_tuple(kv.v));
+  }
+  EXPECT_TRUE(m.contains(2));
+  auto found = m.find(2);
+  ASSERT_TRUE(found != m.end());
+  EXPECT_EQ(234, found->second.x);
+}
+
+TEST(LinkedHashMapTest, ConstKeys) {
+  linked_hash_map<int, int> m;
+  m.insert(std::make_pair(1, 2));
+  // Test that keys are const in iteration.
+  std::pair<const int, int>& p = *m.begin();
+  EXPECT_EQ(1, p.first);
+}
+
+// Tests that iteration from begin() to end() works
+TEST(LinkedHashMapTest, Iteration) {
+  linked_hash_map<int, int> m;
+  EXPECT_TRUE(m.begin() == m.end());
+
+  m.insert(std::make_pair(2, 12));
+  m.insert(std::make_pair(1, 11));
+  m.insert(std::make_pair(3, 13));
+
+  linked_hash_map<int, int>::iterator i = m.begin();
+  ASSERT_TRUE(m.begin() == i);
+  ASSERT_TRUE(m.end() != i);
+  EXPECT_EQ(2, i->first);
+  EXPECT_EQ(12, i->second);
+
+  ++i;
+  ASSERT_TRUE(m.end() != i);
+  EXPECT_EQ(1, i->first);
+  EXPECT_EQ(11, i->second);
+
+  ++i;
+  ASSERT_TRUE(m.end() != i);
+  EXPECT_EQ(3, i->first);
+  EXPECT_EQ(13, i->second);
+
+  ++i;  // Should be the end of the line.
+  ASSERT_TRUE(m.end() == i);
+}
+
+// Tests that reverse iteration from rbegin() to rend() works
+TEST(LinkedHashMapTest, ReverseIteration) {
+  linked_hash_map<int, int> m;
+  EXPECT_TRUE(m.rbegin() == m.rend());
+
+  m.insert(std::make_pair(2, 12));
+  m.insert(std::make_pair(1, 11));
+  m.insert(std::make_pair(3, 13));
+
+  linked_hash_map<int, int>::reverse_iterator i = m.rbegin();
+  ASSERT_TRUE(m.rbegin() == i);
+  ASSERT_TRUE(m.rend() != i);
+  EXPECT_EQ(3, i->first);
+  EXPECT_EQ(13, i->second);
+
+  ++i;
+  ASSERT_TRUE(m.rend() != i);
+  EXPECT_EQ(1, i->first);
+  EXPECT_EQ(11, i->second);
+
+  ++i;
+  ASSERT_TRUE(m.rend() != i);
+  EXPECT_EQ(2, i->first);
+  EXPECT_EQ(12, i->second);
+
+  ++i;  // Should be the end of the line.
+  ASSERT_TRUE(m.rend() == i);
+}
+
+// Tests that clear() works
+TEST(LinkedHashMapTest, Clear) {
+  linked_hash_map<int, int> m;
+  m.insert(std::make_pair(2, 12));
+  m.insert(std::make_pair(1, 11));
+  m.insert(std::make_pair(3, 13));
+
+  ASSERT_EQ(3, m.size());
+
+  m.clear();
+
+  EXPECT_EQ(0, m.size());
+
+  m.clear();  // Make sure we can call it on an empty map.
+
+  EXPECT_EQ(0, m.size());
+}
+
+// Tests that size() works.
+TEST(LinkedHashMapTest, Size) {
+  linked_hash_map<int, int> m;
+  EXPECT_EQ(0, m.size());
+  m.insert(std::make_pair(2, 12));
+  EXPECT_EQ(1, m.size());
+  m.insert(std::make_pair(1, 11));
+  EXPECT_EQ(2, m.size());
+  m.insert(std::make_pair(3, 13));
+  EXPECT_EQ(3, m.size());
+  m.clear();
+  EXPECT_EQ(0, m.size());
+}
+
+// Tests empty()
+TEST(LinkedHashMapTest, Empty) {
+  linked_hash_map<int, int> m;
+  ASSERT_TRUE(m.empty());
+  m.insert(std::make_pair(2, 12));
+  ASSERT_FALSE(m.empty());
+  m.clear();
+  ASSERT_TRUE(m.empty());
+}
+
+TEST(LinkedHashMapTest, Erase) {
+  linked_hash_map<int, int> m;
+  ASSERT_EQ(0, m.size());
+  EXPECT_EQ(0, m.erase(2));  // Nothing to erase yet
+
+  m.insert(std::make_pair(2, 12));
+  ASSERT_EQ(1, m.size());
+  EXPECT_EQ(1, m.erase(2));
+  EXPECT_EQ(0, m.size());
+
+  EXPECT_EQ(0, m.erase(2));  // Make sure nothing bad happens if we repeat.
+  EXPECT_EQ(0, m.size());
+}
+
+TEST(LinkedHashMapTest, Erase2) {
+  linked_hash_map<int, int> m;
+  ASSERT_EQ(0, m.size());
+  EXPECT_EQ(0, m.erase(2));  // Nothing to erase yet
+
+  m.insert(std::make_pair(2, 12));
+  m.insert(std::make_pair(1, 11));
+  m.insert(std::make_pair(3, 13));
+  m.insert(std::make_pair(4, 14));
+  ASSERT_EQ(4, m.size());
+
+  // Erase middle two
+  EXPECT_EQ(1, m.erase(1));
+  EXPECT_EQ(1, m.erase(3));
+
+  EXPECT_EQ(2, m.size());
+
+  // Make sure we can still iterate over everything that's left.
+  linked_hash_map<int, int>::iterator it = m.begin();
+  ASSERT_TRUE(it != m.end());
+  EXPECT_EQ(12, it->second);
+  ++it;
+  ASSERT_TRUE(it != m.end());
+  EXPECT_EQ(14, it->second);
+  ++it;
+  ASSERT_TRUE(it == m.end());
+
+  EXPECT_EQ(0, m.erase(1));  // Make sure nothing bad happens if we repeat.
+  ASSERT_EQ(2, m.size());
+
+  EXPECT_EQ(1, m.erase(2));
+  EXPECT_EQ(1, m.erase(4));
+  ASSERT_EQ(0, m.size());
+
+  EXPECT_EQ(0, m.erase(1));  // Make sure nothing bad happens if we repeat.
+  ASSERT_EQ(0, m.size());
+}
+
+// Test that erase(iter,iter) and erase(iter) compile and work.
+TEST(LinkedHashMapTest, Erase3) {
+  linked_hash_map<int, int> m;
+
+  m.insert(std::make_pair(1, 11));
+  m.insert(std::make_pair(2, 12));
+  m.insert(std::make_pair(3, 13));
+  m.insert(std::make_pair(4, 14));
+
+  // Erase middle two
+  linked_hash_map<int, int>::iterator it2 = m.find(2);
+  linked_hash_map<int, int>::iterator it4 = m.find(4);
+  EXPECT_EQ(m.erase(it2, it4), m.find(4));
+  EXPECT_EQ(2, m.size());
+
+  // Make sure we can still iterate over everything that's left.
+  linked_hash_map<int, int>::iterator it = m.begin();
+  ASSERT_TRUE(it != m.end());
+  EXPECT_EQ(11, it->second);
+  ++it;
+  ASSERT_TRUE(it != m.end());
+  EXPECT_EQ(14, it->second);
+  ++it;
+  ASSERT_TRUE(it == m.end());
+
+  // Erase first one using an iterator.
+  EXPECT_EQ(m.erase(m.begin()), m.find(4));
+
+  // Only the last element should be left.
+  it = m.begin();
+  ASSERT_TRUE(it != m.end());
+  EXPECT_EQ(14, it->second);
+  ++it;
+  ASSERT_TRUE(it == m.end());
+}
+
+// Test all types of insertion
+TEST(LinkedHashMapTest, Insertion) {
+  linked_hash_map<int, int> m;
+  ASSERT_EQ(0, m.size());
+  std::pair<linked_hash_map<int, int>::iterator, bool> result;
+
+  result = m.insert(std::make_pair(2, 12));
+  ASSERT_EQ(1, m.size());
+  EXPECT_TRUE(result.second);
+  EXPECT_EQ(2, result.first->first);
+  EXPECT_EQ(12, result.first->second);
+
+  result = m.insert(std::make_pair(1, 11));
+  ASSERT_EQ(2, m.size());
+  EXPECT_TRUE(result.second);
+  EXPECT_EQ(1, result.first->first);
+  EXPECT_EQ(11, result.first->second);
+
+  result = m.insert(std::make_pair(3, 13));
+  linked_hash_map<int, int>::iterator result_iterator = result.first;
+  ASSERT_EQ(3, m.size());
+  EXPECT_TRUE(result.second);
+  EXPECT_EQ(3, result.first->first);
+  EXPECT_EQ(13, result.first->second);
+
+  result = m.insert(std::make_pair(3, 13));
+  EXPECT_EQ(3, m.size());
+  EXPECT_FALSE(result.second) << "No insertion should have occurred.";
+  EXPECT_TRUE(result_iterator == result.first)
+      << "Duplicate insertion should have given us the original iterator.";
+
+  std::vector<std::pair<int, int>> v = {{3, 13}, {4, 14}, {5, 15}};
+  m.insert(v.begin(), v.end());
+  // Expect 4 and 5 inserted, 3 not inserted.
+  EXPECT_EQ(5, m.size());
+  EXPECT_EQ(14, m.at(4));
+  EXPECT_EQ(15, m.at(5));
+}
+
+static std::pair<const int, int> Pair(int i, int j) { return {i, j}; }
+
+// Test front accessors.
+TEST(LinkedHashMapTest, Front) {
+  linked_hash_map<int, int> m;
+
+  m.insert(std::make_pair(2, 12));
+  m.insert(std::make_pair(1, 11));
+  m.insert(std::make_pair(3, 13));
+
+  EXPECT_EQ(3, m.size());
+  EXPECT_EQ(Pair(2, 12), m.front());
+  m.pop_front();
+  EXPECT_EQ(2, m.size());
+  EXPECT_EQ(Pair(1, 11), m.front());
+  m.pop_front();
+  EXPECT_EQ(1, m.size());
+  EXPECT_EQ(Pair(3, 13), m.front());
+  m.pop_front();
+  EXPECT_TRUE(m.empty());
+}
+
+// Test back accessors.
+TEST(LinkedHashMapTest, Back) {
+  linked_hash_map<int, int> m;
+
+  m.insert(std::make_pair(2, 12));
+  m.insert(std::make_pair(1, 11));
+  m.insert(std::make_pair(3, 13));
+
+  EXPECT_EQ(3, m.size());
+  EXPECT_EQ(Pair(3, 13), m.back());
+  m.pop_back();
+  EXPECT_EQ(2, m.size());
+  EXPECT_EQ(Pair(1, 11), m.back());
+  m.pop_back();
+  EXPECT_EQ(1, m.size());
+  EXPECT_EQ(Pair(2, 12), m.back());
+  m.pop_back();
+  EXPECT_TRUE(m.empty());
+}
+
+TEST(LinkedHashMapTest, Find) {
+  linked_hash_map<int, int> m;
+
+  EXPECT_TRUE(m.end() == m.find(1))
+      << "We shouldn't find anything in an empty map.";
+
+  m.insert(std::make_pair(2, 12));
+  EXPECT_TRUE(m.end() == m.find(1))
+      << "We shouldn't find an element that doesn't exist in the map.";
+
+  std::pair<linked_hash_map<int, int>::iterator, bool> result =
+      m.insert(std::make_pair(1, 11));
+  ASSERT_TRUE(result.second);
+  ASSERT_TRUE(m.end() != result.first);
+  EXPECT_TRUE(result.first == m.find(1))
+      << "We should have found an element we know exists in the map.";
+  EXPECT_EQ(11, result.first->second);
+
+  // Check that a follow-up insertion doesn't affect our original
+  m.insert(std::make_pair(3, 13));
+  linked_hash_map<int, int>::iterator it = m.find(1);
+  ASSERT_TRUE(m.end() != it);
+  EXPECT_EQ(11, it->second);
+
+  m.clear();
+  EXPECT_TRUE(m.end() == m.find(1))
+      << "We shouldn't find anything in a map that we've cleared.";
+}
+
+TEST(LinkedHashMapTest, Contains) {
+  linked_hash_map<int, int> m;
+
+  EXPECT_FALSE(m.contains(1)) << "An empty map shouldn't contain anything.";
+
+  m.insert(std::make_pair(2, 12));
+  EXPECT_FALSE(m.contains(1))
+      << "The map shouldn't contain an element that doesn't exist.";
+
+  m.insert(std::make_pair(1, 11));
+  EXPECT_TRUE(m.contains(1))
+      << "The map should contain an element that we know exists.";
+
+  m.clear();
+  EXPECT_FALSE(m.contains(1))
+      << "A map that we've cleared shouldn't contain anything.";
+}
+
+TEST(LinkedHashMapTest, At) {
+  linked_hash_map<int, int> m = {{1, 2}};
+  EXPECT_EQ(2, m.at(1));
+  EXPECT_DEATH(m.at(3), ".*linked_hash_map::at.*");
+
+  const linked_hash_map<int, int> cm = {{1, 2}};
+  EXPECT_EQ(2, cm.at(1));
+  EXPECT_DEATH(cm.at(3), ".*linked_hash_map::at.*");
+}
+
+TEST(LinkedHashMapTest, Swap) {
+  linked_hash_map<int, int> m1;
+  linked_hash_map<int, int> m2;
+  m1.insert(std::make_pair(1, 1));
+  m1.insert(std::make_pair(2, 2));
+  m2.insert(std::make_pair(3, 3));
+  ASSERT_EQ(2, m1.size());
+  ASSERT_EQ(1, m2.size());
+  m1.swap(m2);
+  ASSERT_EQ(1, m1.size());
+  ASSERT_EQ(2, m2.size());
+}
+
+TEST(LinkedHashMapTest, InitializerList) {
+  linked_hash_map<int, int> m{{1, 2}, {3, 4}};
+  ASSERT_EQ(2, m.size());
+  EXPECT_TRUE(m.contains(1));
+  linked_hash_map<int, int>::iterator it = m.find(1);
+  ASSERT_TRUE(m.end() != it);
+  EXPECT_EQ(2, it->second);
+  EXPECT_TRUE(m.contains(3));
+  it = m.find(3);
+  ASSERT_TRUE(m.end() != it);
+  EXPECT_EQ(4, it->second);
+}
+
+TEST(LinkedHashMapTest, CustomHashAndEquality) {
+  struct CustomIntHash {
+    size_t operator()(int x) const { return x; }
+  };
+  struct CustomIntEq {
+    bool operator()(int x, int y) const { return x == y; }
+  };
+  linked_hash_map<int, int, CustomIntHash, CustomIntEq> m;
+  m.insert(std::make_pair(1, 1));
+  EXPECT_TRUE(m.contains(1));
+  EXPECT_EQ(1, m[1]);
+}
+
+TEST(LinkedHashMapTest, EqualRange) {
+  linked_hash_map<int, int> m{{3, 11}, {1, 13}};
+  const auto& const_m = m;
+
+  EXPECT_THAT(m.equal_range(2), testing::Pair(m.end(), m.end()));
+  EXPECT_THAT(const_m.equal_range(2),
+              testing::Pair(const_m.end(), const_m.end()));
+
+  EXPECT_THAT(m.equal_range(1), testing::Pair(m.find(1), ++m.find(1)));
+  EXPECT_THAT(const_m.equal_range(1),
+              testing::Pair(const_m.find(1), ++const_m.find(1)));
+}
+
+TEST(LinkedHashMapTest, ReserveWorks) {
+  linked_hash_map<int, int> m;
+  EXPECT_GE(10000, m.capacity());
+  EXPECT_EQ(0, m.size());
+  EXPECT_EQ(0.0, m.load_factor());
+  m.reserve(100'000);
+  const int capacity_before_insert = m.capacity();
+  EXPECT_LE(100'000, capacity_before_insert);
+  EXPECT_EQ(0, m.size());
+  EXPECT_EQ(0.0, m.load_factor());
+  m.emplace(1, 1);
+  m.emplace(2, 2);
+  EXPECT_EQ(capacity_before_insert, m.capacity());
+  EXPECT_EQ(2, m.size());
+  EXPECT_LT(0.0, m.load_factor());
+}
+
+TEST(LinkedHashMapTest, HeterogeneousStringViewLookup) {
+  linked_hash_map<std::string, int> map;
+  map["foo"] = 1;
+  map["bar"] = 2;
+  map["blah"] = 3;
+
+  {
+    absl::string_view lookup("foo");
+    auto itr = map.find(lookup);
+    ASSERT_NE(itr, map.end());
+    EXPECT_EQ(1, itr->second);
+  }
+
+  // Not found.
+  {
+    absl::string_view lookup("foobar");
+    EXPECT_EQ(map.end(), map.find(lookup));
+  }
+
+  {
+    absl::string_view lookup("blah");
+    auto itr = map.find(lookup);
+    ASSERT_NE(itr, map.end());
+    EXPECT_EQ(3, itr->second);
+  }
+}
+
+TEST(LinkedHashMapTest, UniversalReferenceWorks) {
+  linked_hash_map<std::string, int> map;
+  std::string s = "very very very very very long string";
+  map[s] = 1;
+  EXPECT_EQ(s, "very very very very very long string");
+}
+
+TEST(LinkedHashMap, ExtractInsert) {
+  linked_hash_map<int, int> m = {{1, 7}, {2, 9}};
+  auto node = m.extract(1);
+  EXPECT_TRUE(node);
+  EXPECT_EQ(node.key(), 1);
+  EXPECT_EQ(node.mapped(), 7);
+  EXPECT_THAT(m, ElementsAre(Pair(2, 9)));
+  EXPECT_FALSE(m.contains(1));
+  EXPECT_TRUE(m.contains(2));
+
+  node.mapped() = 17;
+  m.insert(std::move(node));
+  EXPECT_FALSE(node);
+  EXPECT_THAT(m, ElementsAre(Pair(2, 9), Pair(1, 17)));
+  EXPECT_TRUE(m.contains(2));
+  EXPECT_TRUE(m.contains(1));
+
+  node = m.extract(m.find(1));
+  EXPECT_TRUE(node);
+  EXPECT_EQ(node.key(), 1);
+  EXPECT_EQ(node.mapped(), 17);
+  EXPECT_THAT(m, ElementsAre(Pair(2, 9)));
+}
+
+TEST(LinkedHashMap, Merge) {
+  linked_hash_map<int, int> m = {{1, 7}, {3, 6}};
+  linked_hash_map<int, int> src = {{1, 10}, {2, 9}, {4, 16}};
+
+  m.merge(src);
+
+  EXPECT_THAT(m, ElementsAre(Pair(1, 7), Pair(3, 6), Pair(2, 9), Pair(4, 16)));
+  EXPECT_THAT(src, ElementsAre(Pair(1, 10)));
+  for (int i : {2, 9, 4}) {
+    EXPECT_FALSE(src.contains(i));
+  }
+}
+
+TEST(LinkedHashMap, EraseRange) {
+  linked_hash_map<int, int> map = {{1, 1},  {2, 4},  {3, 9},  {4, 16}, {5, 25},
+                                   {6, 36}, {7, 49}, {8, 64}, {9, 81}};
+  auto start = map.find(3);
+  auto end = map.find(8);
+  auto itr = map.erase(start, end);
+  ASSERT_NE(itr, map.end());
+  EXPECT_THAT(*itr, Pair(8, 64));
+  EXPECT_THAT(map,
+              ElementsAre(Pair(1, 1), Pair(2, 4), Pair(8, 64), Pair(9, 81)));
+  for (int i : {1, 2, 8, 9}) {
+    EXPECT_TRUE(map.contains(i));
+  }
+  for (int i : {3, 4, 5, 6, 7}) {
+    EXPECT_FALSE(map.contains(i));
+  }
+}
+
+TEST(LinkedHashMap, InsertInitializerList) {
+  linked_hash_map<int, int> m;
+  m.insert({{1, 7}, {2, 9}, {3, 29}});
+  EXPECT_THAT(m, ElementsAre(Pair(1, 7), Pair(2, 9), Pair(3, 29)));
+}
+
+TEST(LinkedHashMap, InsertOrAssign) {
+  linked_hash_map<int, int> m;
+  {
+    auto [itr, elem_inserted] = m.insert_or_assign(10, 20);
+    EXPECT_THAT(*itr, Pair(10, 20));
+    EXPECT_EQ(elem_inserted, true);
+  }
+  {
+    auto [itr, elem_inserted] = m.insert_or_assign(10, 30);
+    EXPECT_THAT(*itr, Pair(10, 30));
+    EXPECT_EQ(elem_inserted, false);
+  }
+}
+
+TEST(LinkedHashMap, TryEmplace) {
+  linked_hash_map<int, std::pair<int, std::string>> m;
+  {
+    auto [itr, elem_inserted] = m.try_emplace(10, 20, "string");
+    EXPECT_THAT(*itr, Pair(10, Pair(20, "string")));
+    EXPECT_EQ(elem_inserted, true);
+  }
+  {
+    std::string s = "some string";
+    auto [itr, elem_inserted] = m.try_emplace(10, 2, std::move(s));
+    EXPECT_THAT(*itr, Pair(10, Pair(20, "string")));
+    EXPECT_EQ(elem_inserted, false);
+  }
+}
+
+TEST(LinkedHashMapTest, TryEmplace) {
+  linked_hash_map<int, std::tuple<int, std::string, std::unique_ptr<float>>>
+      map;
+  auto result = map.try_emplace(3, 2, "foo", new float(1.0));
+  EXPECT_TRUE(result.second);
+  EXPECT_EQ(std::get<0>(result.first->second), 2);
+  EXPECT_EQ(std::get<1>(result.first->second), "foo");
+  EXPECT_EQ(*std::get<2>(result.first->second), 1.0);
+
+  // Ptr should not be moved.
+  auto ptr = std::make_unique<float>(3.0);
+  auto result2 = map.try_emplace(3, 22, "foo-bar", std::move(ptr));
+  EXPECT_FALSE(result2.second);
+  EXPECT_EQ(std::get<0>(result.first->second), 2);
+  EXPECT_EQ(std::get<1>(result.first->second), "foo");
+  EXPECT_EQ(*std::get<2>(result.first->second), 1.0);
+  EXPECT_NE(ptr.get(), nullptr);
+}
+
+}  // namespace
+}  // namespace gtl
+
+REGISTER_TYPED_TEST_SUITE_P(MapUtilIntIntTest, ValueMapTests,
+                            UpdateReturnCopyTest, InsertOrReturnExistingTest,
+                            FindOrDieTest, InsertOrDieTest, InsertKeyOrDieTest);
+typedef ::testing::Types<ortools_gtl::linked_hash_map<int, int>>
+    LinkedHashMapIntIntTypes;
+INSTANTIATE_TYPED_TEST_SUITE_P(LinkedHashMapUtilTest, MapUtilIntIntTest,
+                               LinkedHashMapIntIntTypes);
+
+REGISTER_TYPED_TEST_SUITE_P(MapUtilIntIntPtrTest, LookupOrInsertNewTest,
+                            InsertAndDeleteExistingTest, FindPtrOrNullTest,
+                            EraseKeyReturnValuePtrTest);
+typedef ::testing::Types<ortools_gtl::linked_hash_map<int, int*>>
+    LinkedHashMapIntIntPtrTypes;
+INSTANTIATE_TYPED_TEST_SUITE_P(LinkedHashMapUtilTest, MapUtilIntIntPtrTest,
+                               LinkedHashMapIntIntPtrTypes);
diff --git a/ortools/base/strtoint_test.cc b/ortools/base/strtoint_test.cc
new file mode 100644
index 0000000000..66fe5f136a
--- /dev/null
+++ b/ortools/base/strtoint_test.cc
@@ -0,0 +1,59 @@
+// Copyright 2010-2025 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.
+
+#include "ortools/base/strtoint.h"
+
+#include <limits>
+#include <string>
+
+#include "gtest/gtest.h"
+#include "ortools/base/types.h"
+
+namespace operations_research {
+
+TEST(StrutilTest, StrtoFunctions) {
+  // 64-bit conversions are pass-through on all current platforms
+  EXPECT_EQ(0, strtoint64("0"));
+
+  EXPECT_EQ(std::numeric_limits<int64_t>::max(),
+            strtoint64("9223372036854775807"));
+
+  EXPECT_EQ(std::numeric_limits<int64_t>::min(),
+            strtoint64("-9223372036854775808"));
+
+  // safe signed 32-bit conversions within 32-bit range
+  EXPECT_EQ(0, strtoint32("0"));
+
+  EXPECT_EQ(std::numeric_limits<int32_t>::max(), strtoint32("2147483647"));
+
+  EXPECT_EQ(std::numeric_limits<int32_t>::min(), strtoint32("-2147483648"));
+}
+
+TEST(StrutilTest, AtoiFunctions) {
+  // basic atoi32/64 functions, including checks for overflow equivalency
+  // even in invalid conversions
+  EXPECT_EQ(0, atoi64("0"));
+  EXPECT_EQ(12345, atoi64("12345"));
+  EXPECT_EQ(-12345, atoi64("-12345"));
+  EXPECT_EQ(std::numeric_limits<int64_t>::max(), atoi64("9223372036854775807"));
+  EXPECT_EQ(std::numeric_limits<int64_t>::min(),
+            atoi64("-9223372036854775808"));
+
+  EXPECT_EQ(0, atoi32("0"));
+  EXPECT_EQ(12345, atoi32("12345"));
+  EXPECT_EQ(-12345, atoi32("-12345"));
+  EXPECT_EQ(std::numeric_limits<int32_t>::max(), atoi32("2147483647"));
+  EXPECT_EQ(std::numeric_limits<int32_t>::min(), atoi32("-2147483648"));
+}
+
+}  // namespace operations_research
diff --git a/ortools/flatzinc/BUILD.bazel b/ortools/flatzinc/BUILD.bazel
index 8d84487fbd..4c81e76efe 100644
--- a/ortools/flatzinc/BUILD.bazel
+++ b/ortools/flatzinc/BUILD.bazel
@@ -159,5 +159,7 @@ cc_binary(
         "//ortools/base:path",
         "//ortools/base:threadpool",
         "//ortools/util:logging",
+        "@abseil-cpp//absl/flags:flag",
+        "@abseil-cpp//absl/log:flags",
     ],
 )
diff --git a/ortools/linear_solver/proto_solver/BUILD.bazel b/ortools/linear_solver/proto_solver/BUILD.bazel
index 33b4fa4c91..98e396c86c 100644
--- a/ortools/linear_solver/proto_solver/BUILD.bazel
+++ b/ortools/linear_solver/proto_solver/BUILD.bazel
@@ -118,6 +118,7 @@ cc_library(
     srcs = ["scip_params.cc"],
     hdrs = ["scip_params.h"],
     deps = [
+        "//ortools/base:logging",
         "//ortools/linear_solver:scip_helper_macros",
         "@abseil-cpp//absl/status",
         "@abseil-cpp//absl/strings",