diff --git a/packages/belos/src/BelosBiCGStabSolMgr.hpp b/packages/belos/src/BelosBiCGStabSolMgr.hpp
index 647a3ba08932..061e4bcd981a 100644
--- a/packages/belos/src/BelosBiCGStabSolMgr.hpp
+++ b/packages/belos/src/BelosBiCGStabSolMgr.hpp
@@ -272,7 +272,13 @@ namespace Belos {
     static constexpr int defQuorum_default_ = 1;
     static constexpr const char * resScale_default_ = "Norm of Initial Residual";
     static constexpr const char * label_default_ = "Belos";
+// https://stackoverflow.com/questions/24398102/constexpr-and-initialization-of-a-static-const-void-pointer-with-reinterpret-cas
+#if defined(_WIN32) && defined(__clang__)
+    static constexpr std::ostream * outputStream_default_ =
+       __builtin_constant_p(reinterpret_cast<const std::ostream*>(&std::cout));
+#else
     static constexpr std::ostream * outputStream_default_ = &std::cout;
+#endif
 
     // Current solver values.
     MagnitudeType convtol_,achievedTol_;
diff --git a/packages/belos/src/BelosBlockCGSolMgr.hpp b/packages/belos/src/BelosBlockCGSolMgr.hpp
index 486edfa18a6d..151e1a3c90ef 100644
--- a/packages/belos/src/BelosBlockCGSolMgr.hpp
+++ b/packages/belos/src/BelosBlockCGSolMgr.hpp
@@ -362,7 +362,13 @@ namespace Belos {
     static constexpr const char * label_default_ = "Belos";
     static constexpr const char * orthoType_default_ = "ICGS";
     static constexpr bool assertPositiveDefiniteness_default_ = true;
+// https://stackoverflow.com/questions/24398102/constexpr-and-initialization-of-a-static-const-void-pointer-with-reinterpret-cas
+#if defined(_WIN32) && defined(__clang__)
+    static constexpr std::ostream * outputStream_default_ =
+       __builtin_constant_p(reinterpret_cast<const std::ostream*>(&std::cout));
+#else
     static constexpr std::ostream * outputStream_default_ = &std::cout;
+#endif
 
     //
     // Current solver parameters and other values.
diff --git a/packages/belos/src/BelosBlockGmresSolMgr.hpp b/packages/belos/src/BelosBlockGmresSolMgr.hpp
index 00754540b721..ccb54ddfe9f8 100644
--- a/packages/belos/src/BelosBlockGmresSolMgr.hpp
+++ b/packages/belos/src/BelosBlockGmresSolMgr.hpp
@@ -332,7 +332,13 @@ class BlockGmresSolMgr : public SolverManager<ScalarType,MV,OP> {
   static constexpr const char * expResScale_default_ = "Norm of Initial Residual";
   static constexpr const char * label_default_ = "Belos";
   static constexpr const char * orthoType_default_ = "ICGS";
-  static constexpr std::ostream * outputStream_default_ = &std::cout;
+// https://stackoverflow.com/questions/24398102/constexpr-and-initialization-of-a-static-const-void-pointer-with-reinterpret-cas
+#if defined(_WIN32) && defined(__clang__)
+    static constexpr std::ostream * outputStream_default_ =
+       __builtin_constant_p(reinterpret_cast<const std::ostream*>(&std::cout));
+#else
+    static constexpr std::ostream * outputStream_default_ = &std::cout;
+#endif
 
   // Current solver values.
   MagnitudeType convtol_, orthoKappa_, achievedTol_;
diff --git a/packages/belos/src/BelosFixedPointSolMgr.hpp b/packages/belos/src/BelosFixedPointSolMgr.hpp
index 72fbe3ec6880..eaed86b92833 100644
--- a/packages/belos/src/BelosFixedPointSolMgr.hpp
+++ b/packages/belos/src/BelosFixedPointSolMgr.hpp
@@ -285,7 +285,13 @@ namespace Belos {
     static constexpr int outputStyle_default_ = Belos::General;
     static constexpr int outputFreq_default_ = -1;
     static constexpr const char * label_default_ = "Belos";
+// https://stackoverflow.com/questions/24398102/constexpr-and-initialization-of-a-static-const-void-pointer-with-reinterpret-cas
+#if defined(_WIN32) && defined(__clang__)
+    static constexpr std::ostream * outputStream_default_ =
+       __builtin_constant_p(reinterpret_cast<const std::ostream*>(&std::cout));
+#else
     static constexpr std::ostream * outputStream_default_ = &std::cout;
+#endif
 
     //
     // Current solver parameters and other values.
diff --git a/packages/belos/src/BelosGCRODRSolMgr.hpp b/packages/belos/src/BelosGCRODRSolMgr.hpp
index 10af2d81cf05..07843b26d7a4 100644
--- a/packages/belos/src/BelosGCRODRSolMgr.hpp
+++ b/packages/belos/src/BelosGCRODRSolMgr.hpp
@@ -470,7 +470,13 @@ Systems," SIAM Journal on Scientific Computing, 28(5), pp. 1651-1674,
     static constexpr const char * expResScale_default_ = "Norm of Initial Residual";
     static constexpr const char * label_default_ = "Belos";
     static constexpr const char * orthoType_default_ = "ICGS";
+// https://stackoverflow.com/questions/24398102/constexpr-and-initialization-of-a-static-const-void-pointer-with-reinterpret-cas
+#if defined(_WIN32) && defined(__clang__)
+    static constexpr std::ostream * outputStream_default_ =
+       __builtin_constant_p(reinterpret_cast<const std::ostream*>(&std::cout));
+#else
     static constexpr std::ostream * outputStream_default_ = &std::cout;
+#endif
 
     // Current solver values.
     MagnitudeType convTol_, orthoKappa_, achievedTol_;
diff --git a/packages/belos/src/BelosGmresPolyOp.hpp b/packages/belos/src/BelosGmresPolyOp.hpp
index e00cf3754de5..73421f8b4737 100644
--- a/packages/belos/src/BelosGmresPolyOp.hpp
+++ b/packages/belos/src/BelosGmresPolyOp.hpp
@@ -302,7 +302,13 @@ namespace Belos {
     static constexpr const char * label_default_ = "Belos";
     static constexpr const char * polyType_default_ = "Roots";
     static constexpr const char * orthoType_default_ = "DGKS";
+// https://stackoverflow.com/questions/24398102/constexpr-and-initialization-of-a-static-const-void-pointer-with-reinterpret-cas
+#if defined(_WIN32) && defined(__clang__)
+    static constexpr std::ostream * outputStream_default_ =
+       __builtin_constant_p(reinterpret_cast<const std::ostream*>(&std::cout));
+#else
     static constexpr std::ostream * outputStream_default_ = &std::cout;
+#endif
     static constexpr bool damp_default_ = false;
     static constexpr bool addRoots_default_ = true;
 
diff --git a/packages/belos/src/BelosGmresPolySolMgr.hpp b/packages/belos/src/BelosGmresPolySolMgr.hpp
index 59c0d4e7f73c..4bca876d932c 100644
--- a/packages/belos/src/BelosGmresPolySolMgr.hpp
+++ b/packages/belos/src/BelosGmresPolySolMgr.hpp
@@ -322,7 +322,13 @@ class GmresPolySolMgr : public SolverManager<ScalarType,MV,OP> {
   static constexpr bool addRoots_default_ = true;
   static constexpr bool dampPoly_default_ = false;
   static constexpr bool randomRHS_default_ = true; 
-  static constexpr std::ostream * outputStream_default_ = &std::cout;
+// https://stackoverflow.com/questions/24398102/constexpr-and-initialization-of-a-static-const-void-pointer-with-reinterpret-cas
+#if defined(_WIN32) && defined(__clang__)
+    static constexpr std::ostream * outputStream_default_ =
+       __builtin_constant_p(reinterpret_cast<const std::ostream*>(&std::cout));
+#else
+    static constexpr std::ostream * outputStream_default_ = &std::cout;
+#endif
 
   // Current solver values.
   MagnitudeType polyTol_;
diff --git a/packages/belos/src/BelosPCPGSolMgr.hpp b/packages/belos/src/BelosPCPGSolMgr.hpp
index faf2f87130ed..2f49381ffec8 100644
--- a/packages/belos/src/BelosPCPGSolMgr.hpp
+++ b/packages/belos/src/BelosPCPGSolMgr.hpp
@@ -377,7 +377,13 @@ namespace Belos {
     static constexpr int outputFreq_default_ = -1;
     static constexpr const char * label_default_ = "Belos";
     static constexpr const char * orthoType_default_ = "ICGS";
+// https://stackoverflow.com/questions/24398102/constexpr-and-initialization-of-a-static-const-void-pointer-with-reinterpret-cas
+#if defined(_WIN32) && defined(__clang__)
+    static constexpr std::ostream * outputStream_default_ =
+       __builtin_constant_p(reinterpret_cast<const std::ostream*>(&std::cout));
+#else
     static constexpr std::ostream * outputStream_default_ = &std::cout;
+#endif
 
     //
     // Current solver values.
diff --git a/packages/belos/src/BelosPseudoBlockCGSolMgr.hpp b/packages/belos/src/BelosPseudoBlockCGSolMgr.hpp
index 4ec6b0ee49ea..874696379d40 100644
--- a/packages/belos/src/BelosPseudoBlockCGSolMgr.hpp
+++ b/packages/belos/src/BelosPseudoBlockCGSolMgr.hpp
@@ -339,7 +339,13 @@ namespace Belos {
     static constexpr bool foldConvergenceDetectionIntoAllreduce_default_ = false;
     static constexpr const char * resScale_default_ = "Norm of Initial Residual";
     static constexpr const char * label_default_ = "Belos";
+// https://stackoverflow.com/questions/24398102/constexpr-and-initialization-of-a-static-const-void-pointer-with-reinterpret-cas
+#if defined(_WIN32) && defined(__clang__)
+    static constexpr std::ostream * outputStream_default_ =
+       __builtin_constant_p(reinterpret_cast<const std::ostream*>(&std::cout));
+#else
     static constexpr std::ostream * outputStream_default_ = &std::cout;
+#endif
     static constexpr bool genCondEst_default_ = false;
 
     // Current solver values.
diff --git a/packages/belos/src/BelosPseudoBlockGmresSolMgr.hpp b/packages/belos/src/BelosPseudoBlockGmresSolMgr.hpp
index 4772885ef065..392032edf601 100644
--- a/packages/belos/src/BelosPseudoBlockGmresSolMgr.hpp
+++ b/packages/belos/src/BelosPseudoBlockGmresSolMgr.hpp
@@ -501,7 +501,13 @@ namespace Belos {
     static constexpr const char * expResScale_default_ = "Norm of Initial Residual";
     static constexpr const char * label_default_ = "Belos";
     static constexpr const char * orthoType_default_ = "ICGS";
+// https://stackoverflow.com/questions/24398102/constexpr-and-initialization-of-a-static-const-void-pointer-with-reinterpret-cas
+#if defined(_WIN32) && defined(__clang__)
+    static constexpr std::ostream * outputStream_default_ =
+       __builtin_constant_p(reinterpret_cast<const std::ostream*>(&std::cout));
+#else
     static constexpr std::ostream * outputStream_default_ = &std::cout;
+#endif
 
     // Current solver values.
     MagnitudeType convtol_, orthoKappa_, achievedTol_;
diff --git a/packages/belos/src/BelosPseudoBlockStochasticCGSolMgr.hpp b/packages/belos/src/BelosPseudoBlockStochasticCGSolMgr.hpp
index ce9324907824..24c685802ae9 100644
--- a/packages/belos/src/BelosPseudoBlockStochasticCGSolMgr.hpp
+++ b/packages/belos/src/BelosPseudoBlockStochasticCGSolMgr.hpp
@@ -255,7 +255,13 @@ namespace Belos {
     static constexpr int defQuorum_default_ = 1;
     static constexpr const char * resScale_default_ = "Norm of Initial Residual";
     static constexpr const char * label_default_ = "Belos";
+// https://stackoverflow.com/questions/24398102/constexpr-and-initialization-of-a-static-const-void-pointer-with-reinterpret-cas
+#if defined(_WIN32) && defined(__clang__)
+    static constexpr std::ostream * outputStream_default_ =
+       __builtin_constant_p(reinterpret_cast<const std::ostream*>(&std::cout));
+#else
     static constexpr std::ostream * outputStream_default_ = &std::cout;
+#endif
 
     // Current solver values.
     MagnitudeType convtol_;
diff --git a/packages/belos/src/BelosPseudoBlockTFQMRSolMgr.hpp b/packages/belos/src/BelosPseudoBlockTFQMRSolMgr.hpp
index cd2099a3d7e3..69be86a4100e 100644
--- a/packages/belos/src/BelosPseudoBlockTFQMRSolMgr.hpp
+++ b/packages/belos/src/BelosPseudoBlockTFQMRSolMgr.hpp
@@ -270,7 +270,13 @@ namespace Belos {
     static constexpr const char * impResScale_default_ = "Norm of Preconditioned Initial Residual";
     static constexpr const char * expResScale_default_ = "Norm of Initial Residual";
     static constexpr const char * label_default_ = "Belos";
+// https://stackoverflow.com/questions/24398102/constexpr-and-initialization-of-a-static-const-void-pointer-with-reinterpret-cas
+#if defined(_WIN32) && defined(__clang__)
+    static constexpr std::ostream * outputStream_default_ =
+       __builtin_constant_p(reinterpret_cast<const std::ostream*>(&std::cout));
+#else
     static constexpr std::ostream * outputStream_default_ = &std::cout;
+#endif
 
     // Current solver values.
     MagnitudeType convtol_, impTolScale_, achievedTol_;
diff --git a/packages/belos/src/BelosRCGSolMgr.hpp b/packages/belos/src/BelosRCGSolMgr.hpp
index b813da2f7407..605139509ad1 100644
--- a/packages/belos/src/BelosRCGSolMgr.hpp
+++ b/packages/belos/src/BelosRCGSolMgr.hpp
@@ -372,7 +372,13 @@ namespace Belos {
     static constexpr int outputStyle_default_ = Belos::General;
     static constexpr int outputFreq_default_ = -1;
     static constexpr const char * label_default_ = "Belos";
+// https://stackoverflow.com/questions/24398102/constexpr-and-initialization-of-a-static-const-void-pointer-with-reinterpret-cas
+#if defined(_WIN32) && defined(__clang__)
+    static constexpr std::ostream * outputStream_default_ =
+       __builtin_constant_p(reinterpret_cast<const std::ostream*>(&std::cout));
+#else
     static constexpr std::ostream * outputStream_default_ = &std::cout;
+#endif
 
     //
     // Current solver values.
diff --git a/packages/belos/src/BelosTFQMRSolMgr.hpp b/packages/belos/src/BelosTFQMRSolMgr.hpp
index ec69b4a3da80..91e3d5ac485e 100644
--- a/packages/belos/src/BelosTFQMRSolMgr.hpp
+++ b/packages/belos/src/BelosTFQMRSolMgr.hpp
@@ -269,7 +269,13 @@ namespace Belos {
     static constexpr const char * impResScale_default_ = "Norm of Preconditioned Initial Residual";
     static constexpr const char * expResScale_default_ = "Norm of Initial Residual";
     static constexpr const char * label_default_ = "Belos";
+// https://stackoverflow.com/questions/24398102/constexpr-and-initialization-of-a-static-const-void-pointer-with-reinterpret-cas
+#if defined(_WIN32) && defined(__clang__)
+    static constexpr std::ostream * outputStream_default_ =
+       __builtin_constant_p(reinterpret_cast<const std::ostream*>(&std::cout));
+#else
     static constexpr std::ostream * outputStream_default_ = &std::cout;
+#endif
 
     // Current solver values.
     MagnitudeType convtol_, impTolScale_, achievedTol_;
diff --git a/packages/muelu/src/Utils/MueLu_Utilities.cpp b/packages/muelu/src/Utils/MueLu_Utilities.cpp
index 00cbddb9ed91..8ccc4948fc57 100644
--- a/packages/muelu/src/Utils/MueLu_Utilities.cpp
+++ b/packages/muelu/src/Utils/MueLu_Utilities.cpp
@@ -54,9 +54,13 @@
 
 #ifdef HAVE_MPI
 #include <mpi.h>
+#ifdef _WIN32
+#include <winsock2.h>
+#else
 #include <netdb.h>
 #include <arpa/inet.h>
 #endif
+#endif
 
 
 
@@ -265,7 +269,7 @@ bool IsParamValidVariable(const std::string& name)
        int len;
        MPI_Get_processor_name(hostname,&len);
        struct hostent * host = gethostbyname(hostname);
-       int myaddr = (int) htonl(inet_network(inet_ntoa(*(struct in_addr *)host->h_addr)));
+       int myaddr = (int) inet_addr(inet_ntoa(*(struct in_addr *)host->h_addr));
 
        // All-to-all exchange of address integers
        std::vector<int> addressList(numRanks);
diff --git a/packages/zoltan2/core/src/algorithms/color/Zoltan2_AlgHybrid2GL.hpp b/packages/zoltan2/core/src/algorithms/color/Zoltan2_AlgHybrid2GL.hpp
index 580219b6d3b9..6cf2b055ad83 100644
--- a/packages/zoltan2/core/src/algorithms/color/Zoltan2_AlgHybrid2GL.hpp
+++ b/packages/zoltan2/core/src/algorithms/color/Zoltan2_AlgHybrid2GL.hpp
@@ -5,7 +5,11 @@
 #include <unordered_map>
 #include <iostream>
 #include <queue>
+#ifdef _WIN32
+#include <time.h>
+#else
 #include <sys/time.h>
+#endif
 
 #include "Zoltan2_Algorithm.hpp"
 #include "Zoltan2_GraphModel.hpp"
diff --git a/packages/zoltan2/core/src/algorithms/color/Zoltan2_AlgHybridD1-2GL.hpp b/packages/zoltan2/core/src/algorithms/color/Zoltan2_AlgHybridD1-2GL.hpp
index 1885f42714ee..1376b7c61592 100644
--- a/packages/zoltan2/core/src/algorithms/color/Zoltan2_AlgHybridD1-2GL.hpp
+++ b/packages/zoltan2/core/src/algorithms/color/Zoltan2_AlgHybridD1-2GL.hpp
@@ -5,7 +5,11 @@
 #include <unordered_map>
 #include <iostream>
 #include <queue>
+#ifdef _WIN32
+#include <time.h>
+#else
 #include <sys/time.h>
+#endif
 
 #include "Zoltan2_Algorithm.hpp"
 #include "Zoltan2_GraphModel.hpp"
diff --git a/packages/zoltan2/core/src/algorithms/color/Zoltan2_AlgHybridD1.hpp b/packages/zoltan2/core/src/algorithms/color/Zoltan2_AlgHybridD1.hpp
index 36f1d46f8054..627a80d68727 100644
--- a/packages/zoltan2/core/src/algorithms/color/Zoltan2_AlgHybridD1.hpp
+++ b/packages/zoltan2/core/src/algorithms/color/Zoltan2_AlgHybridD1.hpp
@@ -6,7 +6,11 @@
 #include <iostream>
 #include <fstream>
 #include <queue>
+#ifdef _WIN32
+#include <time.h>
+#else
 #include <sys/time.h>
+#endif
 #include <algorithm>
 
 #include "Zoltan2_Algorithm.hpp"
diff --git a/packages/zoltan2/core/src/algorithms/color/Zoltan2_AlgHybridD2.hpp b/packages/zoltan2/core/src/algorithms/color/Zoltan2_AlgHybridD2.hpp
index 953a66d809b2..1fd457e8dd02 100644
--- a/packages/zoltan2/core/src/algorithms/color/Zoltan2_AlgHybridD2.hpp
+++ b/packages/zoltan2/core/src/algorithms/color/Zoltan2_AlgHybridD2.hpp
@@ -5,7 +5,11 @@
 #include <unordered_map>
 #include <iostream>
 #include <queue>
+#ifdef _WIN32
+#include <time.h>
+#else
 #include <sys/time.h>
+#endif
 
 #include "Zoltan2_Algorithm.hpp"
 #include "Zoltan2_GraphModel.hpp"
diff --git a/packages/zoltan2/core/src/algorithms/color/Zoltan2_AlgHybridPD2.hpp b/packages/zoltan2/core/src/algorithms/color/Zoltan2_AlgHybridPD2.hpp
index 75f1707e265e..b1773a4b80f1 100644
--- a/packages/zoltan2/core/src/algorithms/color/Zoltan2_AlgHybridPD2.hpp
+++ b/packages/zoltan2/core/src/algorithms/color/Zoltan2_AlgHybridPD2.hpp
@@ -5,7 +5,11 @@
 #include <unordered_map>
 #include <iostream>
 #include <queue>
+#ifdef _WIN32
+#include <time.h>
+#else
 #include <sys/time.h>
+#endif
 
 #include "Zoltan2_Algorithm.hpp"
 #include "Zoltan2_GraphModel.hpp"
diff --git a/packages/zoltan2/core/src/input/Zoltan2_InputTraits.hpp b/packages/zoltan2/core/src/input/Zoltan2_InputTraits.hpp
index 595c41a03809..ff482f7d7fd9 100644
--- a/packages/zoltan2/core/src/input/Zoltan2_InputTraits.hpp
+++ b/packages/zoltan2/core/src/input/Zoltan2_InputTraits.hpp
@@ -211,6 +211,10 @@ struct InputTraits {
 
 #ifndef DOXYGEN_SHOULD_SKIP_THIS
 
+#ifdef _MSC_VER
+  typedef SSIZE_T ssize_t;
+#endif
+
 // This combination of macros is used to define a single line
 // Z2_STATIC_ASSERT_TYPES for each InputTraits with custom template types
 #define Z2_ISSAME(s,type) (std::is_same< s, type >::value)