diff --git a/examples/dotnet/csintegerprogramming.cs b/examples/dotnet/csintegerprogramming.cs
index d813f3f800..c8e2181f39 100644
--- a/examples/dotnet/csintegerprogramming.cs
+++ b/examples/dotnet/csintegerprogramming.cs
@@ -39,10 +39,10 @@ public class CsIntegerProgramming
     ct.SetCoefficient(x1, 3);
     ct.SetCoefficient(x2, 2);
 
-    int resultStatus = solver.Solve();
+    Solver.ResultStatus resultStatus = solver.Solve();
 
     // Check that the problem has an optimal solution.
-    if (resultStatus != Solver.OPTIMAL)
+    if (resultStatus != Solver.ResultStatus.OPTIMAL)
     {
       Console.WriteLine("The problem does not have an optimal solution!");
       return;
@@ -78,10 +78,10 @@ public class CsIntegerProgramming
     solver.Minimize(x1 + 2 * x2);
     solver.Add(2 * x2 + 3 * x1 >= 17);
 
-    int resultStatus = solver.Solve();
+    Solver.ResultStatus resultStatus = solver.Solve();
 
     // Check that the problem has an optimal solution.
-    if (resultStatus != Solver.OPTIMAL)
+    if (resultStatus != Solver.ResultStatus.OPTIMAL)
     {
       Console.WriteLine("The problem does not have an optimal solution!");
       return;
diff --git a/examples/dotnet/cslinearprogramming.cs b/examples/dotnet/cslinearprogramming.cs
index b88900cd92..28b2128d68 100644
--- a/examples/dotnet/cslinearprogramming.cs
+++ b/examples/dotnet/cslinearprogramming.cs
@@ -57,10 +57,10 @@ public class CsLinearProgramming
     Console.WriteLine("Number of variables = " + solver.NumVariables());
     Console.WriteLine("Number of constraints = " + solver.NumConstraints());
 
-    int resultStatus = solver.Solve();
+    Solver.ResultStatus resultStatus = solver.Solve();
 
     // Check that the problem has an optimal solution.
-    if (resultStatus != Solver.OPTIMAL) {
+    if (resultStatus != Solver.ResultStatus.OPTIMAL) {
       Console.WriteLine("The problem does not have an optimal solution!");
       return;
     }
@@ -120,10 +120,10 @@ public class CsLinearProgramming
       Console.WriteLine(model);
     }
 
-    int resultStatus = solver.Solve();
+    Solver.ResultStatus resultStatus = solver.Solve();
 
     // Check that the problem has an optimal solution.
-    if (resultStatus != Solver.OPTIMAL) {
+    if (resultStatus != Solver.ResultStatus.OPTIMAL) {
       Console.WriteLine("The problem does not have an optimal solution!");
       return;
     }
diff --git a/examples/tests/testlp.cs b/examples/tests/testlp.cs
index 12cf38e711..41c6a44a6a 100644
--- a/examples/tests/testlp.cs
+++ b/examples/tests/testlp.cs
@@ -41,7 +41,7 @@ public class CsTestLp
   {
     Console.WriteLine("Running TestVarOperator");
     Solver solver = new Solver("TestVarOperator",
-                               Solver.CLP_LINEAR_PROGRAMMING);
+                               Solver.OptimizationProblemType.CLP_LINEAR_PROGRAMMING);
     Variable x = solver.MakeNumVar(0.0, 100.0, "x");
     Constraint ct1 = solver.Add(x >= 1);
     Constraint ct2 = solver.Add(x <= 1);
@@ -73,7 +73,7 @@ public class CsTestLp
   {
     Console.WriteLine("Running TestVarAddition");
     Solver solver = new Solver("TestVarAddition",
-                               Solver.CLP_LINEAR_PROGRAMMING);
+                               Solver.OptimizationProblemType.CLP_LINEAR_PROGRAMMING);
     Variable x = solver.MakeNumVar(0.0, 100.0, "x");
     Variable y = solver.MakeNumVar(0.0, 100.0, "y");
     Constraint ct1 = solver.Add(x + y == 1);
@@ -95,7 +95,7 @@ public class CsTestLp
   {
     Console.WriteLine("Running TestVarMultiplication");
     Solver solver = new Solver("TestVarMultiplication",
-                                   Solver.CLP_LINEAR_PROGRAMMING);
+                                   Solver.OptimizationProblemType.CLP_LINEAR_PROGRAMMING);
     Variable x = solver.MakeNumVar(0.0, 100.0, "x");
     Variable y = solver.MakeNumVar(0.0, 100.0, "y");
     Constraint ct1 = solver.Add(3 * x == 1);
@@ -121,7 +121,7 @@ public class CsTestLp
   {
     Console.WriteLine("Running TestBinaryOperations");
     Solver solver = new Solver("TestBinaryOperations",
-                               Solver.CLP_LINEAR_PROGRAMMING);
+                               Solver.OptimizationProblemType.CLP_LINEAR_PROGRAMMING);
     Variable x = solver.MakeNumVar(0.0, 100.0, "x");
     Variable y = solver.MakeNumVar(0.0, 100.0, "y");
     Constraint ct1 = solver.Add(x == y);
@@ -147,7 +147,7 @@ public class CsTestLp
   {
     Console.WriteLine("Running TestInequalities");
     Solver solver = new Solver("TestInequalities",
-                               Solver.CLP_LINEAR_PROGRAMMING);
+                               Solver.OptimizationProblemType.CLP_LINEAR_PROGRAMMING);
     Variable x = solver.MakeNumVar(0.0, 100.0, "x");
     Variable y = solver.MakeNumVar(0.0, 100.0, "y");
     Constraint ct1 = solver.Add(2 * (x + 3) + 5 * (y + x -1) >= 3);
@@ -175,7 +175,7 @@ public class CsTestLp
   static void TestSumArray()
   {
     Console.WriteLine("Running TestSumArray");
-    Solver solver = new Solver("TestSumArray", Solver.CLP_LINEAR_PROGRAMMING);
+    Solver solver = new Solver("TestSumArray", Solver.OptimizationProblemType.CLP_LINEAR_PROGRAMMING);
     Variable[] x = solver.MakeBoolVarArray(10, "x");
     Constraint ct1 = solver.Add(x.Sum() == 3);
     CheckDoubleEq(ct1.GetCoefficient(x[0]), 1.0, "test1");
@@ -191,7 +191,7 @@ public class CsTestLp
   static void TestObjective()
   {
     Console.WriteLine("Running TestObjective");
-    Solver solver = new Solver("TestObjective", Solver.CLP_LINEAR_PROGRAMMING);
+    Solver solver = new Solver("TestObjective", Solver.OptimizationProblemType.CLP_LINEAR_PROGRAMMING);
     Variable x = solver.MakeNumVar(0.0, 100.0, "x");
     Variable y = solver.MakeNumVar(0.0, 100.0, "y");
     solver.Maximize(x);
diff --git a/ortools/algorithms/csharp/knapsack_solver.i b/ortools/algorithms/csharp/knapsack_solver.i
index a0a9c928df..a0110399ad 100644
--- a/ortools/algorithms/csharp/knapsack_solver.i
+++ b/ortools/algorithms/csharp/knapsack_solver.i
@@ -13,8 +13,9 @@
 
 // TODO(user): Refactor this file to adhere to the SWIG style guide.
 
-%include <stdint.i>
-%include <std_vector.i>
+%include "enums.swg"
+%include "stdint.i"
+%include "std_vector.i"
 
 %include "ortools/base/base.i"
 
diff --git a/ortools/algorithms/java/knapsack_solver.i b/ortools/algorithms/java/knapsack_solver.i
index 6102827a2f..6053e49925 100644
--- a/ortools/algorithms/java/knapsack_solver.i
+++ b/ortools/algorithms/java/knapsack_solver.i
@@ -18,8 +18,8 @@
 //
 // TODO(user): test all lines marked "untested".
 
-%include <enums.swg>
-%include <stdint.i>
+%include "enums.swg"
+%include "stdint.i"
 
 %include "ortools/base/base.i"
 %import "ortools/util/java/vector.i"
diff --git a/ortools/algorithms/python/knapsack_solver.i b/ortools/algorithms/python/knapsack_solver.i
index 8ae50164d5..a51f8d68c0 100644
--- a/ortools/algorithms/python/knapsack_solver.i
+++ b/ortools/algorithms/python/knapsack_solver.i
@@ -17,7 +17,7 @@
 // - examples/python/knapsack.py
 // - ./pywrapknapsack_solver_test.py
 
-%include <stdint.i>
+%include "stdint.i"
 
 %include "ortools/base/base.i"
 %import "ortools/util/python/vector.i"
diff --git a/ortools/base/base.i b/ortools/base/base.i
index a65f939bc2..c15f46a327 100644
--- a/ortools/base/base.i
+++ b/ortools/base/base.i
@@ -23,17 +23,14 @@
 // rename.  For example, an operator< in a class without a rename.
 // 362 is similar to 503 but for operator=.
 
-%include <typemaps.i>
-%include <exception.i>
-%include <stdint.i>
-%include <std_string.i>
+%include "typemaps.i"
+%include "exception.i"
+%include "stdint.i"
+%include "std_string.i"
 
 %{
 #include <cstdint>
-#include <map>
-#include <set>
 #include <string>
-#include <unordered_set>
 #include <vector>
 
 #include "ortools/base/basictypes.h"
@@ -67,50 +64,24 @@ COPY_TYPEMAPS(uint64_t, uint64);
 
 #endif  // SWIGPYTHON
 
-#ifdef SWIGJAVA
+#if defined(SWIGJAVA) || defined(SWIGCSHARP)
 %{
 #include <cstdint>
-#include <map>
-#include <set>
 #include <string>
-#include <unordered_set>
 #include <vector>
 
 #include "ortools/base/basictypes.h"
 %}
 
-%include <stdint.i>
-%include <std_string.i>
+%include "stdint.i"
+%include "std_string.i"
 
 typedef int int32;
 typedef unsigned int uint32;
 typedef int64_t int64;
 typedef uint64_t uint64;
 
-#endif  // SWIGJAVA
-
-#ifdef SWIGCSHARP
-%include "enumsimple.swg"
-%{
-#include <cstdint>
-#include <map>
-#include <set>
-#include <string>
-#include <unordered_set>
-#include <vector>
-
-#include "ortools/base/basictypes.h"
-%}
-
-%include <std_string.i>
-%include <stdint.i>
-
-typedef int int32;
-typedef unsigned int uint32;
-typedef int64_t int64;
-typedef uint64_t uint64;
-
-#endif  // SWIGCSHARP
+#endif  // defined(SWIGJAVA) || defined(SWIGCSHARP)
 
 // SWIG macros for explicit API declaration.
 // Usage:
diff --git a/ortools/base/integral_types.h b/ortools/base/integral_types.h
index 33c97ffa12..b7d4ee7030 100644
--- a/ortools/base/integral_types.h
+++ b/ortools/base/integral_types.h
@@ -41,7 +41,6 @@ typedef uint64_t uint64;
 // and different size specifiers in format strings
 #undef GG_LONGLONG
 #undef GG_ULONGLONG
-#undef GG_LL_FORMAT
 
 #define GG_LONGLONG(x) INT64_C(x)
 #define GG_ULONGLONG(x) UINT64_C(x)
diff --git a/ortools/base/python/callbacks.i b/ortools/base/python/callbacks.i
deleted file mode 100644
index f9ad9317f0..0000000000
--- a/ortools/base/python/callbacks.i
+++ /dev/null
@@ -1,145 +0,0 @@
-// Copyright 2010-2018 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.
-
-// SWIG wrapping of some Callbacks in python.
-// This doesn't directly expose a C++ API; rather it provides typemaps that can
-// be used by other .i files to easily expose APIs that use callbacks.
-// See its usage in ../../constraint_solver/python/constraint_solver.i.
-//
-// TODO(user): Nuke this file and use the callback wrapping code in
-// base/swig/python/... when it is available.
-
-%include "ortools/base/base.i"
-
-%import "ortools/base/callback.h"
-
-%{
-static std::string PyCallbackString(PyObject* pyfunc) {
-  PyObject* pyresult = PyObject_CallFunctionObjArgs(pyfunc, nullptr);
-  std::string result;
-  if (!pyresult) {
-    PyErr_SetString(PyExc_RuntimeError,
-                    "ResultCallback<std::string> invocation failed.");
-  } else {
-    result = PyString_AsString(pyresult);
-    Py_DECREF(pyresult);
-  }
-  return result;
-}
-%}
-
-%typemap(in) ResultCallback<std::string>* {
-  if (!PyCallable_Check($input)) {
-    PyErr_SetString(PyExc_TypeError, "Need a callable object!");
-    SWIG_fail;
-  }
-  $1 = NewPermanentCallback(&PyCallbackString, $input);
-}
-
-%{
-static int64 PyCallback1Int64Int64(PyObject* pyfunc, int64 i) {
-  // () needed to force creation of one-element tuple
-  PyObject* pyresult = PyEval_CallFunction(pyfunc, "(l)", static_cast<long>(i));
-  int64 result = 0;
-  if (!pyresult) {
-    PyErr_SetString(PyExc_RuntimeError,
-                    "ResultCallback1<int64, int64> invocation failed.");
-  } else {
-    result = PyInt_AsLong(pyresult);
-    Py_DECREF(pyresult);
-  }
-  return result;
-}
-%}
-
-%typemap(in) ResultCallback1<int64, int64>* {
-  if (!PyCallable_Check($input)) {
-    PyErr_SetString(PyExc_TypeError, "Need a callable object!");
-    SWIG_fail;
-  }
-  $1 = NewPermanentCallback(&PyCallback1Int64Int64, $input);
-}
-
-%{
-static int64 PyCallback2Int64Int64Int64(PyObject* pyfunc, int64 i, int64 j) {
-  PyObject* pyresult = PyEval_CallFunction(pyfunc, "ll", static_cast<long>(i),
-                                           static_cast<long>(j));
-  int64 result = 0;
-  if (!pyresult) {
-    PyErr_SetString(PyExc_RuntimeError,
-                    "ResultCallback2<int64, int64, int64> invocation failed.");
-  } else {
-    result = PyInt_AsLong(pyresult);
-    Py_DECREF(pyresult);
-  }
-  return result;
-}
-%}
-
-%typemap(in) ResultCallback2<int64, int64, int64>* {
-  if (!PyCallable_Check($input)) {
-    PyErr_SetString(PyExc_TypeError, "Need a callable object!");
-    SWIG_fail;
-  }
-  $1 = NewPermanentCallback(&PyCallback2Int64Int64Int64, $input);
-}
-
-%{
-static int64 PyCallback3Int64Int64Int64Int64(PyObject* pyfunc,
-                                             int64 i, int64 j, int64 k) {
-  PyObject* pyresult = PyEval_CallFunction(pyfunc, "lll", static_cast<long>(i),
-                                           static_cast<long>(j),
-                                           static_cast<long>(k));
-  int64 result = 0;
-  if (!pyresult) {
-    PyErr_SetString(
-        PyExc_RuntimeError,
-        "ResultCallback3<int64, int64, int64, int64> invocation failed.");
-  } else {
-    result = PyInt_AsLong(pyresult);
-    Py_DECREF(pyresult);
-  }
-  return result;
-}
-%}
-
-%typemap(in) ResultCallback3<int64, int64, int64, int64>* {
-  if (!PyCallable_Check($input)) {
-    PyErr_SetString(PyExc_TypeError, "Need a callable object!");
-    SWIG_fail;
-  }
-  $1 = NewPermanentCallback(&PyCallback3Int64Int64Int64Int64, $input);
-}
-
-%{
-static bool PyCallbackBool(PyObject* pyfunc) {
-  PyObject* pyresult = PyObject_CallFunctionObjArgs(pyfunc, nullptr);
-  bool result = false;
-  if (!pyresult) {
-    PyErr_SetString(PyExc_RuntimeError,
-                    "ResultCallback<bool> invocation failed.");
-  } else {
-    result = PyObject_IsTrue(pyresult);
-    Py_DECREF(pyresult);
-  }
-  return result;
-}
-%}
-
-%typemap(in) ResultCallback<bool>* {
-  if (!PyCallable_Check($input)) {
-    PyErr_SetString(PyExc_TypeError, "Need a callable object!");
-    SWIG_fail;
-  }
-  $1 = NewPermanentCallback(&PyCallbackBool, $input);
-}
diff --git a/ortools/constraint_solver/csharp/constraint_solver.i b/ortools/constraint_solver/csharp/constraint_solver.i
index b47b0d0ce3..a7d2edc896 100644
--- a/ortools/constraint_solver/csharp/constraint_solver.i
+++ b/ortools/constraint_solver/csharp/constraint_solver.i
@@ -19,16 +19,16 @@ using System.Runtime.InteropServices;
 using System.Collections;
 %}
 
-%include <stdint.i>
-%include <exception.i>
-%include <std_vector.i>
+%include "enumsimple.swg"
+%include "stdint.i"
+%include "exception.i"
+%include "std_vector.i"
 
 %include "ortools/base/base.i"
 %include "ortools/util/csharp/tuple_set.i"
 %include "ortools/util/csharp/functions.i"
 %include "ortools/util/csharp/proto.i"
 
-
 // We need to forward-declare the proto here, so that PROTO_INPUT involving it
 // works correctly. The order matters very much: this declaration needs to be
 // before the %{ #include ".../constraint_solver.h" %}.
@@ -58,7 +58,6 @@ class SearchLimitParameters;
 #include <string>
 #include <vector>
 
-#include "ortools/base/callback.h"
 #include "ortools/base/integral_types.h"
 #include "ortools/constraint_solver/constraint_solver.h"
 #include "ortools/constraint_solver/constraint_solveri.h"
diff --git a/ortools/constraint_solver/java/constraint_solver.i b/ortools/constraint_solver/java/constraint_solver.i
index 6b53c06741..462dcecdf2 100644
--- a/ortools/constraint_solver/java/constraint_solver.i
+++ b/ortools/constraint_solver/java/constraint_solver.i
@@ -13,9 +13,9 @@
 
 // TODO(user): Refactor this file to adhere to the SWIG style guide.
 
-%include <enumsimple.swg>
-%include <exception.i>
-%include <stdint.i>
+%include "enumsimple.swg"
+%include "exception.i"
+%include "stdint.i"
 
 %include "ortools/base/base.i"
 %include "ortools/util/java/tuple_set.i"
diff --git a/ortools/constraint_solver/python/constraint_solver.i b/ortools/constraint_solver/python/constraint_solver.i
index 65df0690af..617d55dc08 100644
--- a/ortools/constraint_solver/python/constraint_solver.i
+++ b/ortools/constraint_solver/python/constraint_solver.i
@@ -31,7 +31,7 @@
 // - examples/python/sudoku.py
 // - examples/python/zebra.py
 
-%include <stdint.i>
+%include "stdint.i"
 
 %include "ortools/base/base.i"
 %include "ortools/util/python/proto.i"
@@ -2240,3 +2240,4 @@ class PyConstraint(Constraint):
 
 
 }  // %pythoncode
+
diff --git a/ortools/constraint_solver/python/routing.i b/ortools/constraint_solver/python/routing.i
index be6e9776a8..7e4f328bf7 100644
--- a/ortools/constraint_solver/python/routing.i
+++ b/ortools/constraint_solver/python/routing.i
@@ -13,7 +13,6 @@
 
 // TODO(user): Refactor this file to adhere to the SWIG style guide.
 
-%include <stdint.i>
 %include "ortools/base/base.i"
 
 %include "ortools/constraint_solver/python/constraint_solver.i"
diff --git a/ortools/constraint_solver/search.cc b/ortools/constraint_solver/search.cc
index 65d7a27662..a9b9a6e1b9 100644
--- a/ortools/constraint_solver/search.cc
+++ b/ortools/constraint_solver/search.cc
@@ -1489,7 +1489,7 @@ int64 StaticEvaluatorSelector::ChooseVariable() {
     }
     // Sort is stable here given the tie-breaking rules in comp_.
     std::sort(elements_.begin(), elements_.end(), comp_);
-    solver_->SaveAndSetValue(&first_, GG_LONGLONG(0));
+    solver_->SaveAndSetValue<int64>(&first_, 0);
   }
   for (int64 i = first_; i < elements_.size(); ++i) {
     const Element& element = elements_[i];
diff --git a/ortools/dotnet/Google.OrTools.FSharp/OrTools.fs b/ortools/dotnet/Google.OrTools.FSharp/OrTools.fs
index 570dba052b..0d42c2d1aa 100644
--- a/ortools/dotnet/Google.OrTools.FSharp/OrTools.fs
+++ b/ortools/dotnet/Google.OrTools.FSharp/OrTools.fs
@@ -150,7 +150,7 @@ module FSharp =
       | MultidimensionSCIP ->
           MultidimensionSCIP.Id
 
-    let solver = new KnapsackSolver(algorithm, name)
+    let solver = new KnapsackSolver(enum<KnapsackSolver.SolverType>(algorithm), name)
 
     // transform lists to compatible structures for C++ Solver
     let profits = new KInt64Vector( List.toArray profits )
@@ -234,7 +234,9 @@ module FSharp =
       | LP lp -> lp.Id
       | IP ip -> ip.Id
 
-    let solver = new Solver(solverOptions.SolverName, algorithm)
+    let solverType = enum<Solver.OptimizationProblemType>(algorithm)
+
+    let solver = new Solver(solverOptions.SolverName, solverType)
 
     // Detect errors on required parameters
     if (solverOptions.ConstraintMatrix.IsNone && solverOptions.ConstraintVectorUpperBound.IsNone && solverOptions.ConstraintVectorLowerBound.IsNone)
@@ -343,7 +345,7 @@ module FSharp =
     let resultStatus = solver.Solve();
 
     match resultStatus with
-    | status when status <> Solver.OPTIMAL ->
+    | status when status <> Solver.ResultStatus.OPTIMAL ->
         printfn "The problem does not have an optimal solution!"
         exit 0
     | _ ->
@@ -355,4 +357,3 @@ module FSharp =
       printfn "%-10s: %f " (sprintf "var[%i]" i) ((solver.LookupVariableOrNull(sprintf "var[%i]" i)).SolutionValue())
 
     solver
-
diff --git a/ortools/graph/csharp/graph.i b/ortools/graph/csharp/graph.i
index 67f16a694c..fc8197f254 100644
--- a/ortools/graph/csharp/graph.i
+++ b/ortools/graph/csharp/graph.i
@@ -22,7 +22,8 @@
 // - examples/csharp/assignment.cs
 // - examples/csharp/csflow.cs
 
-%include <stdint.i>
+%include "enums.swg"
+%include "stdint.i"
 
 %include "ortools/base/base.i"
 
diff --git a/ortools/graph/java/graph.i b/ortools/graph/java/graph.i
index cd3e0c3e10..b1e80e25b9 100644
--- a/ortools/graph/java/graph.i
+++ b/ortools/graph/java/graph.i
@@ -29,7 +29,8 @@
 //
 // TODO(user): test all the APIs that are currently marked as 'untested'.
 
-%include <stdint.i>
+%include "enums.swg"
+%include "stdint.i"
 
 %include "ortools/base/base.i"
 
diff --git a/ortools/graph/python/graph.i b/ortools/graph/python/graph.i
index 4949c98532..3cc3cb495f 100644
--- a/ortools/graph/python/graph.i
+++ b/ortools/graph/python/graph.i
@@ -26,11 +26,11 @@
 //
 // TODO(user): test all the APIs that are currently marked as 'untested'.
 
-%include <stdint.i>
+%include "stdint.i"
 
 %include "ortools/base/base.i"
 
-%include "ortools/util/python/vector.i"
+%import "ortools/util/python/vector.i"
 
 %import "ortools/graph/ebert_graph.h"
 
diff --git a/ortools/graph/samples/SimpleMaxFlowProgram.cs b/ortools/graph/samples/SimpleMaxFlowProgram.cs
index 117e9eaf56..ed1360fc30 100644
--- a/ortools/graph/samples/SimpleMaxFlowProgram.cs
+++ b/ortools/graph/samples/SimpleMaxFlowProgram.cs
@@ -45,11 +45,11 @@ public class SimpleMaxFlowProgram
 
     // [START solve]
     // Find the maximum flow between node 0 and node 4.
-    int solveStatus = maxFlow.Solve(0, 4);
+    MaxFlow.Status solveStatus = maxFlow.Solve(0, 4);
     // [END solve]
 
     // [START print_solution]
-    if (solveStatus == MaxFlow.OPTIMAL)
+    if (solveStatus == MaxFlow.Status.OPTIMAL)
     {
       Console.WriteLine("Max. flow: " + maxFlow.OptimalFlow());
       Console.WriteLine("");
diff --git a/ortools/graph/samples/SimpleMinCostFlowProgram.cs b/ortools/graph/samples/SimpleMinCostFlowProgram.cs
index ef98b30c04..254e3a7fa2 100644
--- a/ortools/graph/samples/SimpleMinCostFlowProgram.cs
+++ b/ortools/graph/samples/SimpleMinCostFlowProgram.cs
@@ -57,11 +57,11 @@ public class SimpleMinCostFlowProgram
 
     // [START solve]
     // Find the min cost flow.
-    int solveStatus = minCostFlow.Solve();
+    MinCostFlow.Status solveStatus = minCostFlow.Solve();
     // [END solve]
 
     // [START print_solution]
-    if (solveStatus == MinCostFlow.OPTIMAL)
+    if (solveStatus == MinCostFlow.Status.OPTIMAL)
     {
       Console.WriteLine("Minimum cost: " + minCostFlow.OptimalCost());
       Console.WriteLine("");
diff --git a/ortools/linear_solver/csharp/SolverHelper.cs b/ortools/linear_solver/csharp/SolverHelper.cs
index 139e977283..af46970860 100644
--- a/ortools/linear_solver/csharp/SolverHelper.cs
+++ b/ortools/linear_solver/csharp/SolverHelper.cs
@@ -191,10 +191,10 @@ public partial class Solver {
   }
 
   public static Solver CreateSolver(String name, String type) {
-    System.Reflection.FieldInfo fieldInfo =
-        typeof(Solver).GetField(type);
-    if (fieldInfo != null) {
-      return new Solver(name, (int)fieldInfo.GetValue(null));
+    Solver.OptimizationProblemType solver_type =
+        Solver.OptimizationProblemType.GLOP_LINEAR_PROGRAMMING;
+    if (Enum.TryParse(type, true, out solver_type)) {
+      return new Solver(name, solver_type);
     } else {
       return null;
     }
diff --git a/ortools/linear_solver/csharp/linear_solver.i b/ortools/linear_solver/csharp/linear_solver.i
index 30589db909..94836668d5 100644
--- a/ortools/linear_solver/csharp/linear_solver.i
+++ b/ortools/linear_solver/csharp/linear_solver.i
@@ -28,9 +28,9 @@
 // - examples/csharp/cslinearprogramming.cs
 // - examples/csharp/csintegerprogramming.cs
 
-
-%include <stdint.i>
-%include <std_vector.i>
+%include "enums.swg"
+%include "stdint.i"
+%include "std_vector.i"
 
 %include "ortools/base/base.i"
 
diff --git a/ortools/linear_solver/java/linear_solver.i b/ortools/linear_solver/java/linear_solver.i
index 6277387e2c..0fc54717c7 100644
--- a/ortools/linear_solver/java/linear_solver.i
+++ b/ortools/linear_solver/java/linear_solver.i
@@ -25,15 +25,16 @@
 //
 // TODO(user): unit test all the APIs that are currently marked with 'no test'.
 
-%include <enums.swg>  // For native Java enum support.
-%include <stdint.i>
+%include "enums.swg"  // For native Java enum support.
+%include "stdint.i"
 
 %include "ortools/base/base.i"
 
 // We prefer our in-house vector wrapper to std_vector.i, because it
 // converts to and from native java arrays.
-%include "ortools/util/java/vector.i"
+%import "ortools/util/java/vector.i"
 
+%include "ortools/util/java/proto.i"
 
 // We need to forward-declare the proto here, so that the PROTO_* macros
 // involving them work correctly. The order matters very much: this declaration
@@ -55,6 +56,7 @@ typedef uint64_t uint64;
 import java.lang.reflect.*;
 %}
 
+
 %extend operations_research::MPSolver {
   std::string exportModelAsLpFormat(bool obfuscated) {
     std::string output;
diff --git a/ortools/linear_solver/python/linear_solver.i b/ortools/linear_solver/python/linear_solver.i
index 5986f42420..6d092fc047 100644
--- a/ortools/linear_solver/python/linear_solver.i
+++ b/ortools/linear_solver/python/linear_solver.i
@@ -28,10 +28,12 @@
 //
 // TODO(user): test all the APIs that are currently marked as 'untested'.
 
-%include <stdint.i>
+%include "stdint.i"
 
 %include "ortools/base/base.i"
-%include "ortools/util/python/vector.i"
+%import "ortools/util/python/vector.i"
+
+%include "ortools/util/python/proto.i"
 
 // We need to forward-declare the proto here, so that the PROTO_* macros
 // involving them work correctly. The order matters very much: this declaration
diff --git a/ortools/linear_solver/samples/SimpleMipProgram.cs b/ortools/linear_solver/samples/SimpleMipProgram.cs
index 83aa03866e..29f7dd1512 100644
--- a/ortools/linear_solver/samples/SimpleMipProgram.cs
+++ b/ortools/linear_solver/samples/SimpleMipProgram.cs
@@ -48,9 +48,9 @@ public class SimpleMipProgram
     // [END objective]
 
     // [START solve]
-    int resultStatus = solver.Solve();
+    Solver.ResultStatus resultStatus = solver.Solve();
     // Check that the problem has an optimal solution.
-    if (resultStatus != Solver.OPTIMAL)
+    if (resultStatus != Solver.ResultStatus.OPTIMAL)
     {
       Console.WriteLine("The problem does not have an optimal solution!");
       return;
diff --git a/ortools/sat/cp_model_presolve.cc b/ortools/sat/cp_model_presolve.cc
index c514d5b2a4..cd98d05ebb 100644
--- a/ortools/sat/cp_model_presolve.cc
+++ b/ortools/sat/cp_model_presolve.cc
@@ -1125,7 +1125,7 @@ void ExtractEnforcementLiteralFromLinearConstraint(ConstraintProto* ct,
   for (int i = 0; i < arg.vars_size(); ++i) {
     // Only work with binary variables.
     //
-    // TODO(user): This could be generalized to non-binary variable
+    // TODO(user,user): This could be generalized to non-binary variable
     // but that would require introducing the encoding "literal <=> integer
     // variable at is min/max" and using this literal in the enforcement list.
     // It is thus a bit more involved, and might not be as useful.
diff --git a/ortools/sat/csharp/sat.i b/ortools/sat/csharp/sat.i
index 005c54bff0..766b6c76d6 100644
--- a/ortools/sat/csharp/sat.i
+++ b/ortools/sat/csharp/sat.i
@@ -17,7 +17,7 @@ using System.Runtime.InteropServices;
 using System.Collections;
 %}
 
-%include <stdint.i>
+%include "stdint.i"
 
 %include "ortools/base/base.i"
 %include "ortools/util/csharp/proto.i"
diff --git a/ortools/sat/java/sat.i b/ortools/sat/java/sat.i
index 24695a2b91..42db3e97d2 100644
--- a/ortools/sat/java/sat.i
+++ b/ortools/sat/java/sat.i
@@ -11,6 +11,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+%include "stdint.i"
+
 %include "ortools/base/base.i"
 
 %include "ortools/util/java/proto.i"
@@ -21,6 +23,9 @@
 #include "ortools/sat/swig_helper.h"
 %}
 
+typedef int64_t int64;
+typedef uint64_t uint64;
+
 %module(directors="1") operations_research_sat
 
 PROTO_INPUT(operations_research::sat::CpModelProto,
diff --git a/ortools/sat/linear_programming_constraint.cc b/ortools/sat/linear_programming_constraint.cc
index eb9902e9a5..cfc3e810a8 100644
--- a/ortools/sat/linear_programming_constraint.cc
+++ b/ortools/sat/linear_programming_constraint.cc
@@ -641,6 +641,7 @@ bool LinearProgrammingConstraint::ComputeNewLinearConstraint(
 
   // Scale the lp_multipliers to the CP world (still Fractional though).
   std::vector<std::pair<RowIndex, Fractional>> cp_multipliers;
+  Fractional max_cp_multi = 0.0;
   Fractional min_cp_multi = glop::kInfinity;
   const Fractional global_scaling =
       bound_scaling_factor_ / lp_data_.objective_scaling_factor();
@@ -663,6 +664,7 @@ bool LinearProgrammingConstraint::ComputeNewLinearConstraint(
         (1e6 / magnitude_diff) / std::abs(cp_multi);
     *scaling = std::max(*scaling, wanted_scaling);
 
+    max_cp_multi = std::max(std::abs(cp_multi), max_cp_multi);
     min_cp_multi = std::min(std::abs(cp_multi), min_cp_multi);
     cp_multipliers.push_back({row, cp_multi});
   }
@@ -673,6 +675,11 @@ bool LinearProgrammingConstraint::ComputeNewLinearConstraint(
     *scaling = std::max(*scaling, 1e6 / lp_multipliers_norm);
   }
 
+  // Make sure the scaled coeff are not too big.
+  if (max_cp_multi > 0.0) {
+    *scaling = std::min(*scaling, 1e12 / max_cp_multi);
+  }
+
   // Scale the multipliers by *scaling.
   //
   // TODO(user): Maybe use int128 to avoid overflow?
@@ -759,6 +766,9 @@ IntegerValue LinearProgrammingConstraint::ExactLpReasonning() {
   // The "objective constraint" behave like if the unscaled cp multiplier was
   // 1.0, so we will multiply it by this number and add it to reduced_costs.
   const IntegerValue obj_scale(std::round(scaling));
+  if (obj_scale == 0) {
+    return kMinIntegerValue;  // Overflow.
+  }
   if (!AddLinearExpressionMultiple(obj_scale, integer_objective_,
                                    &reduced_costs)) {
     return kMinIntegerValue;  // Overflow.
diff --git a/ortools/sat/python/sat.i b/ortools/sat/python/sat.i
index e1fe24e399..ac00d5313f 100644
--- a/ortools/sat/python/sat.i
+++ b/ortools/sat/python/sat.i
@@ -13,7 +13,7 @@
 
 // This .i file exposes the sat cp_model API.
 
-%include <stdint.i>
+%include "stdint.i"
 
 %include "ortools/base/base.i"
 %include "ortools/util/python/proto.i"
@@ -32,7 +32,6 @@ typedef uint64_t uint64;
 
 %module(directors="1") operations_research_sat
 
-
 PY_PROTO_TYPEMAP(ortools.sat.cp_model_pb2,
                  CpModelProto,
                  operations_research::sat::CpModelProto);
@@ -92,3 +91,4 @@ PY_PROTO_TYPEMAP(ortools.sat.sat_parameters_pb2,
 %include "ortools/sat/swig_helper.h"
 
 %unignoreall
+
diff --git a/ortools/sat/sat_solver.cc b/ortools/sat/sat_solver.cc
index c1d4faae00..3d42aea9e5 100644
--- a/ortools/sat/sat_solver.cc
+++ b/ortools/sat/sat_solver.cc
@@ -74,8 +74,12 @@ void SatSolver::SetNumVariables(int num_variables) {
   trail_->Resize(num_variables);
   decision_policy_->IncreaseNumVariables(num_variables);
   pb_constraints_.Resize(num_variables);
-  decisions_.resize(num_variables);
   same_reason_identifier_.Resize(num_variables);
+
+  // The +1 is a bit tricky, it is because in
+  // EnqueueDecisionAndBacktrackOnConflict() we artificially enqueue the
+  // decision before checking if it is not already assigned.
+  decisions_.resize(num_variables + 1);
 }
 
 int64 SatSolver::num_branches() const { return counters_.num_branches; }
@@ -815,6 +819,7 @@ int SatSolver::EnqueueDecisionAndBacktrackOnConflict(Literal true_literal) {
   CHECK(PropagationIsDone());
 
   if (is_model_unsat_) return kUnsatTrailIndex;
+  DCHECK_LT(CurrentDecisionLevel(), decisions_.size());
   decisions_[CurrentDecisionLevel()].literal = true_literal;
   int first_propagation_index = trail_->Index();
   ReapplyDecisionsUpTo(CurrentDecisionLevel(), &first_propagation_index);
@@ -1472,8 +1477,8 @@ std::string SatSolver::StatusString(Status status) const {
 std::string SatSolver::RunningStatisticsString() const {
   const double time_in_s = timer_.Get();
   return absl::StrFormat(
-      "%6.2fs, mem:%s, fails:%d, "
-      "depth:%d, clauses:%d, tmp:%d, bin:%u, restarts:%d, vars:%d",
+      "%6.2fs, mem:%s, fails:%d, depth:%d, clauses:%d, tmp:%d, bin:%u, "
+      "restarts:%d, vars:%d",
       time_in_s, MemoryUsage(), counters_.num_failures, CurrentDecisionLevel(),
       clauses_propagator_.num_clauses() -
           clauses_propagator_.num_removable_clauses(),
diff --git a/ortools/util/csharp/vector.i b/ortools/util/csharp/vector.i
index f78b30a46a..39243407bb 100644
--- a/ortools/util/csharp/vector.i
+++ b/ortools/util/csharp/vector.i
@@ -17,8 +17,8 @@
 // Normally we'd simply use %include "std_vector.i" with the %template
 // directive (see http://www.swig.org/Doc1.3/Library.html#Library_nn15), but
 // in google3 we can't, because exceptions are forbidden.
-//
-// TODO(user): move to base/swig/java.
+
+%include "stdint.i"
 
 %include "ortools/base/base.i"
 
@@ -27,6 +27,9 @@
 #include "ortools/base/integral_types.h"
 %}
 
+typedef int64_t int64;
+typedef uint64_t uint64;
+
 %define VECTOR_AS_CSHARP_ARRAY(TYPE, CTYPE, CSHARPTYPE)
 %typemap(ctype)    const std::vector<TYPE>&  %{ int length$argnum, CTYPE* %}
 %typemap(imtype)   const std::vector<TYPE>&  %{ int length$argnum, CSHARPTYPE[] %}
diff --git a/ortools/util/java/vector.i b/ortools/util/java/vector.i
index badeb665e4..844a161ebc 100644
--- a/ortools/util/java/vector.i
+++ b/ortools/util/java/vector.i
@@ -20,7 +20,8 @@
 //
 // TODO(user): move to base/swig/java.
 
-%include <stdint.i>
+%include "stdint.i"
+
 %include "ortools/base/base.i"
 
 %{
diff --git a/ortools/util/python/proto.i b/ortools/util/python/proto.i
index 70d2331950..43ca643310 100644
--- a/ortools/util/python/proto.i
+++ b/ortools/util/python/proto.i
@@ -1,4 +1,4 @@
-// Copyright 2010-2014 Google
+// Copyright 2010-2018 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
@@ -11,7 +11,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// TODO(user): make this SWIG file comply with the SWIG style guide.
 %include "ortools/base/base.i"
 
 %import "ortools/base/integral_types.h"
diff --git a/ortools/util/python/vector.i b/ortools/util/python/vector.i
index 17d31c57cd..fc9bd0e8ba 100644
--- a/ortools/util/python/vector.i
+++ b/ortools/util/python/vector.i
@@ -29,11 +29,7 @@
 // Note(user): for an unknown reason, using the (handy) method PyObjAs()
 // defined in base/swig/python-swig.cc seems to cause issues, so we can't
 // use a generic, templated type checker.
-  // Get const std::vector<string>& "in" typemap.
-%include "python/std_vector.i"
-%include "python/std_map.i"
-%include "python/std_set.i"
-%include "python/std_list.i"
+  // Get const std::vector<std::string>& "in" typemap.
 
 %define PY_LIST_OUTPUT_TYPEMAP(type, checker, py_converter)
 %typecheck(SWIG_TYPECHECK_POINTER) const std::vector<type>&,
@@ -71,14 +67,12 @@
 }
 %typemap(in,numinputs=0)
  std::vector<type>* OUTPUT (std::vector<type> temp),
- std::unordered_set<type>* OUTPUT (std::unordered_set<type> temp),
  std::set<type>* OUTPUT (std::set<type> temp) {
   $1 = &temp;
 }
 %typemap(argout)
      std::vector<type>* OUTPUT,
-     std::set<type>* OUTPUT,
-     std::unordered_set<type>* OUTPUT {
+     std::set<type>* OUTPUT {
   %append_output(list_output_helper($1, &py_converter));
 }
 %typemap(out) std::vector<type> {
@@ -88,9 +82,6 @@
   $result = vector_output_helper($1, &py_converter);
 }
 
-%apply std::vector<type>* OUTPUT { std::vector<type>* OUTPUT }
-%apply std::set<type>* OUTPUT { std::set<type>* OUTPUT }
-
 %enddef  // PY_LIST_OUTPUT_TYPEMAP
 
 PY_LIST_OUTPUT_TYPEMAP(int, PyInt_Check, PyInt_FromLong);
@@ -164,9 +155,6 @@ PY_LIST_OUTPUT_TYPEMAP(double, PyFloat_Check, PyFloat_FromDouble);
   }
 }
 
-%apply const std::vector<std::vector<type> >& {
-  const std::vector<std::vector<type> >&
-}
 %enddef  // PY_LIST_LIST_INPUT_TYPEMAP
 
 PY_LIST_LIST_INPUT_TYPEMAP(int64, SwigPyIntOrLong_Check);