diff --git a/mert/FeatureArray.cpp b/mert/FeatureArray.cpp
index 7e9de1cf8..62f9ceda5 100644
--- a/mert/FeatureArray.cpp
+++ b/mert/FeatureArray.cpp
@@ -6,94 +6,104 @@
  *
  */
 
+#include <fstream>
 #include "FeatureArray.h"
 #include "FileStream.h"
 #include "Util.h"
 
-
 FeatureArray::FeatureArray()
     : m_index(""), m_num_features(0), m_sparse_flag(false) {}
 
 FeatureArray::~FeatureArray() {}
 
-void FeatureArray::savetxt(std::ofstream& outFile)
+void FeatureArray::savetxt(ostream* os)
 {
-  outFile << FEATURES_TXT_BEGIN << " " << m_index << " " << m_array.size()
-          << " " << m_num_features << " " << m_features << std::endl;
+  *os << FEATURES_TXT_BEGIN << " " << m_index << " " << m_array.size()
+          << " " << m_num_features << " " << m_features << endl;
   for (featarray_t::iterator i = m_array.begin(); i != m_array.end(); ++i) {
-    i->savetxt(outFile);
-    outFile << std::endl;
+    i->savetxt(os);
+    *os << endl;
   }
-  outFile << FEATURES_TXT_END << std::endl;
+  *os << FEATURES_TXT_END << endl;
 }
 
-void FeatureArray::savebin(std::ofstream& outFile)
+void FeatureArray::savebin(ostream* os)
 {
-  outFile << FEATURES_BIN_BEGIN << " " << m_index << " " << m_array.size()
-          << " " << m_num_features << " " << m_features << std::endl;
+  *os << FEATURES_BIN_BEGIN << " " << m_index << " " << m_array.size()
+          << " " << m_num_features << " " << m_features << endl;
   for (featarray_t::iterator i = m_array.begin(); i != m_array.end(); ++i)
-    i->savebin(outFile);
+    i->savebin(os);
 
-  outFile << FEATURES_BIN_END << std::endl;
+  *os << FEATURES_BIN_END << endl;
 }
 
 
-void FeatureArray::save(std::ofstream& inFile, bool bin)
+void FeatureArray::save(ostream* os, bool bin)
 {
-  if (size()>0)
-    (bin)?savebin(inFile):savetxt(inFile);
+  if (size() <= 0) return;
+  if (bin) {
+    savebin(os);
+  } else {
+    savetxt(os);
+  }
 }
 
-void FeatureArray::save(const std::string &file, bool bin)
+void FeatureArray::save(const string &file, bool bin)
 {
-
-  std::ofstream outFile(file.c_str(), std::ios::out); // matches a stream with a file. Opens the file
-
-  save(outFile);
-
-  outFile.close();
+  ofstream ofs(file.c_str(), ios::out);
+  if (!ofs) {
+    cerr << "Failed to open " << file << endl;
+    exit(1);
+  }
+  ostream *os = &ofs;
+  save(os, bin);
+  ofs.close();
 }
 
-void FeatureArray::loadbin(ifstream& inFile, size_t n)
+void FeatureArray::save(bool bin)
+{
+  save(&cout, bin);
+}
+
+void FeatureArray::loadbin(istream* is, size_t n)
 {
   FeatureStats entry(m_num_features);
-
-  for (size_t i=0 ; i < n; i++) {
-    entry.loadbin(inFile);
+  for (size_t i = 0 ; i < n; i++) {
+    entry.loadbin(is);
     add(entry);
   }
 }
 
-void FeatureArray::loadtxt(ifstream& inFile, size_t n)
+void FeatureArray::loadtxt(istream* is, size_t n)
 {
   FeatureStats entry(m_num_features);
 
-  for (size_t i=0 ; i < n; i++) {
-    entry.loadtxt(inFile);
+  for (size_t i = 0; i < n; i++) {
+    entry.loadtxt(is);
     add(entry);
     if (entry.getSparse().size()>0)
       m_sparse_flag = true;
   }
 }
 
-void FeatureArray::load(ifstream& inFile)
+void FeatureArray::load(istream* is)
 {
-  size_t number_of_entries=0;
-  bool binmode=false;
+  size_t number_of_entries = 0;
+  bool binmode = false;
 
-  std::string substring, stringBuf;
-  std::string::size_type loc;
+  string substring, stringBuf;
+  string::size_type loc;
 
-  std::getline(inFile, stringBuf);
-  if (!inFile.good()) {
+  getline(*is, stringBuf);
+  if (!is->good()) {
     return;
   }
 
   if (!stringBuf.empty()) {
     if ((loc = stringBuf.find(FEATURES_TXT_BEGIN)) == 0) {
-      binmode=false;
+      binmode = false;
     } else if ((loc = stringBuf.find(FEATURES_BIN_BEGIN)) == 0) {
-      binmode=true;
+      binmode = true;
     } else {
       TRACE_ERR("ERROR: FeatureArray::load(): Wrong header");
       return;
@@ -108,33 +118,35 @@ void FeatureArray::load(ifstream& inFile)
     m_features = stringBuf;
   }
 
-  (binmode)?loadbin(inFile, number_of_entries):loadtxt(inFile, number_of_entries);
+  if (binmode) {
+    loadbin(is, number_of_entries);
+  } else {
+    loadtxt(is, number_of_entries);
+  }
 
-  std::getline(inFile, stringBuf);
+  getline(*is, stringBuf);
   if (!stringBuf.empty()) {
-    if ((loc = stringBuf.find(FEATURES_TXT_END)) != 0 && (loc = stringBuf.find(FEATURES_BIN_END)) != 0) {
+    if ((loc = stringBuf.find(FEATURES_TXT_END)) != 0 &&
+        (loc = stringBuf.find(FEATURES_BIN_END)) != 0) {
       TRACE_ERR("ERROR: FeatureArray::load(): Wrong footer");
       return;
     }
   }
 }
 
-void FeatureArray::load(const std::string &file)
+void FeatureArray::load(const string &file)
 {
-  TRACE_ERR("loading data from " << file << std::endl);
-
-  inputfilestream inFile(file); // matches a stream with a file. Opens the file
-
-  load((ifstream&) inFile);
-
-  inFile.close();
-
+  TRACE_ERR("loading data from " << file << endl);
+  inputfilestream input_stream(file); // matches a stream with a file. Opens the file
+  istream* is = &input_stream;
+  load(is);
+  input_stream.close();
 }
 
 void FeatureArray::merge(FeatureArray& e)
 {
   //dummy implementation
-  for (size_t i=0; i<e.size(); i++)
+  for (size_t i = 0; i < e.size(); i++)
     add(e.get(i));
 }
 
diff --git a/mert/FeatureArray.h b/mert/FeatureArray.h
index fa5590ac1..1581120db 100644
--- a/mert/FeatureArray.h
+++ b/mert/FeatureArray.h
@@ -11,7 +11,6 @@
 
 #include <vector>
 #include <iostream>
-#include <fstream>
 #include "FeatureStats.h"
 
 using namespace std;
@@ -89,17 +88,16 @@ public:
     m_features = f;
   }
 
-  void savetxt(ofstream& outFile);
-  void savebin(ofstream& outFile);
-  void save(ofstream& outFile, bool bin=false);
-  void save(const std::string &file, bool bin=false);
-  inline void save(bool bin=false) {
-    save("/dev/stdout",bin);
-  }
+  void savetxt(std::ostream* os);
+  void savebin(std::ostream* os);
+  void save(std::ostream* os, bool bin=false);
 
-  void loadtxt(ifstream& inFile, size_t n);
-  void loadbin(ifstream& inFile, size_t n);
-  void load(ifstream& inFile);
+  void save(const std::string &file, bool bin=false);
+  void save(bool bin=false);
+
+  void loadtxt(std::istream* is, size_t n);
+  void loadbin(std::istream* is, size_t n);
+  void load(std::istream* is);
   void load(const std::string &file);
 
   bool check_consistency() const;
diff --git a/mert/FeatureData.cpp b/mert/FeatureData.cpp
index 61413a3f5..3bcaa71b5 100644
--- a/mert/FeatureData.cpp
+++ b/mert/FeatureData.cpp
@@ -13,44 +13,41 @@
 #include "Util.h"
 #include <cstdio>
 
-static const float MIN_FLOAT=-1.0*numeric_limits<float>::max();
-static const float MAX_FLOAT=numeric_limits<float>::max();
+static const float MIN_FLOAT = -1.0 * numeric_limits<float>::max();
+static const float MAX_FLOAT = numeric_limits<float>::max();
 
 FeatureData::FeatureData()
     : m_num_features(0),
       m_sparse_flag(false) {}
 
-void FeatureData::save(std::ofstream& outFile, bool bin)
+void FeatureData::save(ostream* os, bool bin)
 {
   for (featdata_t::iterator i = m_array.begin(); i != m_array.end(); i++)
-    i->save(outFile, bin);
+    i->save(os, bin);
 }
 
-void FeatureData::save(const std::string &file, bool bin)
+void FeatureData::save(const string &file, bool bin)
 {
   if (file.empty()) return;
-
-  TRACE_ERR("saving the array into " << file << std::endl);
-
-  std::ofstream outFile(file.c_str(), std::ios::out); // matches a stream with a file. Opens the file
-
-  save(outFile, bin);
-
-  outFile.close();
+  TRACE_ERR("saving the array into " << file << endl);
+  ofstream ofs(file.c_str(), ios::out); // matches a stream with a file. Opens the file
+  ostream* os = &ofs;
+  save(os, bin);
+  ofs.close();
 }
 
-void FeatureData::load(ifstream& inFile)
+void FeatureData::load(istream* is)
 {
   FeatureArray entry;
 
-  while (!inFile.eof()) {
+  while (!is->eof()) {
 
-    if (!inFile.good()) {
-      std::cerr << "ERROR FeatureData::load inFile.good()" << std::endl;
+    if (!is->good()) {
+      cerr << "ERROR FeatureData::load inFile.good()" << endl;
     }
 
     entry.clear();
-    entry.load(inFile);
+    entry.load(is);
 
     if (entry.size() == 0)
       break;
@@ -66,19 +63,16 @@ void FeatureData::load(ifstream& inFile)
 }
 
 
-void FeatureData::load(const std::string &file)
+void FeatureData::load(const string &file)
 {
-  TRACE_ERR("loading feature data from " << file << std::endl);
-
-  inputfilestream inFile(file); // matches a stream with a file. Opens the file
-
-  if (!inFile) {
+  TRACE_ERR("loading feature data from " << file << endl);
+  inputfilestream input_stream(file); // matches a stream with a file. Opens the file
+  if (!input_stream) {
     throw runtime_error("Unable to open feature file: " + file);
   }
-
-  load((ifstream&) inFile);
-
-  inFile.close();
+  istream* is = &input_stream;
+  load(is);
+  input_stream.close();
 }
 
 void FeatureData::add(FeatureArray& e)
@@ -93,7 +87,7 @@ void FeatureData::add(FeatureArray& e)
   }
 }
 
-void FeatureData::add(FeatureStats& e, const std::string& sent_idx)
+void FeatureData::add(FeatureStats& e, const string& sent_idx)
 {
   if (exists(sent_idx)) { // array at position e.getIndex() already exists
     //enlarge array at position e.getIndex()
@@ -132,7 +126,7 @@ void FeatureData::setIndex()
   }
 }
 
-void FeatureData::setFeatureMap(const std::string& feat)
+void FeatureData::setFeatureMap(const string& feat)
 {
   m_num_features = 0;
   m_features = feat;
diff --git a/mert/FeatureData.h b/mert/FeatureData.h
index 171f880af..7f10777b0 100644
--- a/mert/FeatureData.h
+++ b/mert/FeatureData.h
@@ -92,12 +92,13 @@ public:
   }
 
   void save(const std::string &file, bool bin=false);
-  void save(ofstream& outFile, bool bin=false);
+  void save(std::ostream* os, bool bin=false);
+
   inline void save(bool bin=false) {
-    save("/dev/stdout", bin);
+    save(&cout, bin);
   }
 
-  void load(ifstream& inFile);
+  void load(std::istream* is);
   void load(const std::string &file);
 
   bool check_consistency() const;
diff --git a/mert/FeatureStats.cpp b/mert/FeatureStats.cpp
index eb8d96b3d..38aa31328 100644
--- a/mert/FeatureStats.cpp
+++ b/mert/FeatureStats.cpp
@@ -8,6 +8,7 @@
 
 #include "FeatureStats.h"
 
+#include <fstream>
 #include <cmath>
 #include "Util.h"
 
@@ -89,7 +90,7 @@ FeatureStats::FeatureStats(const size_t size)
   memset(m_array, 0, GetArraySizeWithBytes());
 }
 
-FeatureStats::FeatureStats(std::string &theString)
+FeatureStats::FeatureStats(string &theString)
     : m_available_size(0), m_entries(0), m_array(NULL)
 {
   set(theString);
@@ -144,9 +145,9 @@ void FeatureStats::addSparse(const string& name, FeatureStatsType v)
   m_map.set(name,v);
 }
 
-void FeatureStats::set(std::string &theString)
+void FeatureStats::set(string &theString)
 {
-  std::string substring, stringBuf;
+  string substring, stringBuf;
   reset();
 
   while (!theString.empty()) {
@@ -163,48 +164,50 @@ void FeatureStats::set(std::string &theString)
   }
 }
 
-
-void FeatureStats::loadbin(std::ifstream& inFile)
+void FeatureStats::loadbin(istream* is)
 {
-  inFile.read((char*) m_array, GetArraySizeWithBytes());
+  is->read(reinterpret_cast<char*>(m_array),
+           static_cast<streamsize>(GetArraySizeWithBytes()));
 }
 
-void FeatureStats::loadtxt(std::ifstream& inFile)
+void FeatureStats::loadtxt(istream* is)
 {
-  std::string theString;
-  std::getline(inFile, theString);
-  set(theString);
+  string line;
+  getline(*is, line);
+  set(line);
 }
 
-void FeatureStats::loadtxt(const std::string &file)
+void FeatureStats::loadtxt(const string &file)
 {
-  //    TRACE_ERR("loading the stats from " << file << std::endl);
-
-  std::ifstream inFile(file.c_str(), std::ios::in); // matches a stream with a file. Opens the file
-
-  loadtxt(inFile);
+  ifstream ifs(file.c_str(), ios::in);
+  if (!ifs) {
+    cerr << "Failed to open " << file << endl;
+    exit(1);
+  }
+  istream* is = &ifs;
+  loadtxt(is);
 }
 
-
-void FeatureStats::savetxt(const std::string &file)
+void FeatureStats::savetxt(const string &file)
 {
-//      TRACE_ERR("saving the stats into " << file << std::endl);
-
-  std::ofstream outFile(file.c_str(), std::ios::out); // matches a stream with a file. Opens the file
-
-  savetxt(outFile);
+  ofstream ofs(file.c_str(), ios::out);
+  ostream* os = &ofs;
+  savetxt(os);
 }
 
-
-void FeatureStats::savetxt(std::ofstream& outFile)
+void FeatureStats::savetxt(ostream* os)
 {
-//      TRACE_ERR("saving the stats" << std::endl);
-  outFile << *this;
+  *os << *this;
 }
 
-void FeatureStats::savebin(std::ofstream& outFile)
+void FeatureStats::savetxt() {
+  savetxt(&cout);
+}
+
+void FeatureStats::savebin(ostream* os)
 {
-  outFile.write((char*) m_array, GetArraySizeWithBytes());
+  os->write(reinterpret_cast<char*>(m_array),
+            static_cast<streamsize>(GetArraySizeWithBytes()));
 }
 
 ostream& operator<<(ostream& o, const FeatureStats& e)
diff --git a/mert/FeatureStats.h b/mert/FeatureStats.h
index b71a99fe1..87dc70e0f 100644
--- a/mert/FeatureStats.h
+++ b/mert/FeatureStats.h
@@ -10,7 +10,6 @@
 #define MERT_FEATURE_STATS_H_
 
 #include <cstring>
-#include <fstream>
 #include <iostream>
 #include <map>
 #include <string>
@@ -118,15 +117,13 @@ public:
   }
 
   void savetxt(const std::string &file);
-  void savetxt(ofstream& outFile);
-  void savebin(ofstream& outFile);
-  inline void savetxt() {
-    savetxt("/dev/stdout");
-  }
+  void savetxt(std::ostream* os);
+  void savebin(std::ostream* os);
+  void savetxt();
 
   void loadtxt(const std::string &file);
-  void loadtxt(ifstream& inFile);
-  void loadbin(ifstream& inFile);
+  void loadtxt(std::istream* is);
+  void loadbin(std::istream* is);
 
   /**
    * Write the whole object to a stream.
diff --git a/mert/FileStream.h b/mert/FileStream.h
index 671e996ca..3fd489cd7 100644
--- a/mert/FileStream.h
+++ b/mert/FileStream.h
@@ -2,6 +2,7 @@
 #define MERT_FILE_STREAM_H_
 
 #include <fstream>
+#include <iostream>
 #include <streambuf>
 #include <string>
 
diff --git a/mert/ScoreArray.cpp b/mert/ScoreArray.cpp
index 3afa9ce1a..972bca0e7 100644
--- a/mert/ScoreArray.cpp
+++ b/mert/ScoreArray.cpp
@@ -13,74 +13,82 @@
 ScoreArray::ScoreArray()
     : m_num_scores(0), m_index("") {}
 
-void ScoreArray::savetxt(std::ofstream& outFile, const std::string& sctype)
+void ScoreArray::savetxt(ostream* os, const string& sctype)
 {
-  outFile << SCORES_TXT_BEGIN << " " << m_index << " " << m_array.size()
-          << " " << m_num_scores << " " << sctype << std::endl;
+  *os << SCORES_TXT_BEGIN << " " << m_index << " " << m_array.size()
+          << " " << m_num_scores << " " << sctype << endl;
   for (scorearray_t::iterator i = m_array.begin(); i !=m_array.end(); i++) {
-    i->savetxt(outFile);
-    outFile << std::endl;
+    i->savetxt(os);
+    *os << endl;
   }
-  outFile << SCORES_TXT_END << std::endl;
+  *os << SCORES_TXT_END << endl;
 }
 
-void ScoreArray::savebin(std::ofstream& outFile, const std::string& sctype)
+void ScoreArray::savebin(ostream* os, const string& score_type)
 {
-  outFile << SCORES_BIN_BEGIN << " " << m_index << " " << m_array.size()
-          << " " << m_num_scores << " " << sctype << std::endl;
-  for (scorearray_t::iterator i = m_array.begin(); i !=m_array.end(); i++)
-    i->savebin(outFile);
-
-  outFile << SCORES_BIN_END << std::endl;
+  *os << SCORES_BIN_BEGIN << " " << m_index << " " << m_array.size()
+          << " " << m_num_scores << " " << score_type << endl;
+  for (scorearray_t::iterator i = m_array.begin();
+       i != m_array.end(); i++) {
+    i->savebin(os);
+  }
+  *os << SCORES_BIN_END << endl;
 }
 
-void ScoreArray::save(std::ofstream& inFile, const std::string& sctype, bool bin)
+void ScoreArray::save(ostream* os, const string& score_type, bool bin)
 {
   if (size() <= 0) return;
   if (bin) {
-    savebin(inFile, sctype);
+    savebin(os, score_type);
   } else {
-    savetxt(inFile, sctype);
+    savetxt(os, score_type);
   }
 }
 
-void ScoreArray::save(const std::string &file, const std::string& sctype, bool bin)
+void ScoreArray::save(const string &file, const string& score_type, bool bin)
 {
-  std::ofstream outFile(file.c_str(), std::ios::out); // matches a stream with a file. Opens the file
-  save(outFile, sctype, bin);
-  outFile.close();
-}
-
-void ScoreArray::loadbin(ifstream& inFile, size_t n)
-{
-  ScoreStats entry(m_num_scores);
-
-  for (size_t i=0 ; i < n; i++) {
-    entry.loadbin(inFile);
-    add(entry);
+  ofstream ofs(file.c_str(), ios::out);
+  if (!ofs) {
+    cerr << "Failed to open " << file << endl;
+    exit(1);
   }
+  ostream* os = &ofs;
+  save(os, score_type, bin);
+  ofs.close();
 }
 
-void ScoreArray::loadtxt(ifstream& inFile, size_t n)
+void ScoreArray::save(const string& score_type, bool bin) {
+  save(&cout, score_type, bin);
+}
+
+void ScoreArray::loadbin(istream* is, size_t n)
 {
   ScoreStats entry(m_num_scores);
-
   for (size_t i = 0; i < n; i++) {
-    entry.loadtxt(inFile);
+    entry.loadbin(is);
     add(entry);
   }
 }
 
-void ScoreArray::load(ifstream& inFile)
+void ScoreArray::loadtxt(istream* is, size_t n)
+{
+  ScoreStats entry(m_num_scores);
+  for (size_t i = 0; i < n; i++) {
+    entry.loadtxt(is);
+    add(entry);
+  }
+}
+
+void ScoreArray::load(istream* is)
 {
   size_t number_of_entries = 0;
   bool binmode = false;
 
-  std::string substring, stringBuf;
-  std::string::size_type loc;
+  string substring, stringBuf;
+  string::size_type loc;
 
-  std::getline(inFile, stringBuf);
-  if (!inFile.good()) {
+  getline(*is, stringBuf);
+  if (!is->good()) {
     return;
   }
 
@@ -105,12 +113,12 @@ void ScoreArray::load(ifstream& inFile)
   }
 
   if (binmode) {
-    loadbin(inFile, number_of_entries);
+    loadbin(is, number_of_entries);
   } else {
-    loadtxt(inFile, number_of_entries);
+    loadtxt(is, number_of_entries);
   }
 
-  std::getline(inFile, stringBuf);
+  getline(*is, stringBuf);
   if (!stringBuf.empty()) {
     if ((loc = stringBuf.find(SCORES_TXT_END)) != 0 &&
         (loc = stringBuf.find(SCORES_BIN_END)) != 0) {
@@ -120,15 +128,13 @@ void ScoreArray::load(ifstream& inFile)
   }
 }
 
-void ScoreArray::load(const std::string &file)
+void ScoreArray::load(const string &file)
 {
-  TRACE_ERR("loading data from " << file << std::endl);
-
-  inputfilestream inFile(file); // matches a stream with a file. Opens the file
-
-  load((ifstream&) inFile);
-
-  inFile.close();
+  TRACE_ERR("loading data from " << file << endl);
+  inputfilestream input_stream(file); // matches a stream with a file. Opens the file
+  istream* is = &input_stream;
+  load(is);
+  input_stream.close();
 }
 
 
diff --git a/mert/ScoreArray.h b/mert/ScoreArray.h
index e1fb71357..70d7ec0e6 100644
--- a/mert/ScoreArray.h
+++ b/mert/ScoreArray.h
@@ -95,17 +95,15 @@ public:
     m_num_scores = v;
   }
 
-  void savetxt(ofstream& outFile, const std::string& sctype);
-  void savebin(ofstream& outFile, const std::string& sctype);
-  void save(ofstream& outFile, const std::string& sctype, bool bin=false);
-  void save(const std::string &file, const std::string& sctype, bool bin=false);
-  inline void save(const std::string& sctype, bool bin=false) {
-    save("/dev/stdout", sctype, bin);
-  }
+  void savetxt(std::ostream* os, const std::string& score_type);
+  void savebin(std::ostream* os, const std::string& score_type);
+  void save(std::ostream* os, const std::string& score_type, bool bin=false);
+  void save(const std::string &file, const std::string& score_type, bool bin=false);
+  void save(const std::string& score_type, bool bin=false);
 
-  void loadtxt(ifstream& inFile, size_t n);
-  void loadbin(ifstream& inFile, size_t n);
-  void load(ifstream& inFile);
+  void loadtxt(std::istream* is, size_t n);
+  void loadbin(std::istream* is, size_t n);
+  void load(std::istream* is);
   void load(const std::string &file);
 
   bool check_consistency() const;
diff --git a/mert/ScoreData.cpp b/mert/ScoreData.cpp
index 5a561816a..b4454dc4e 100644
--- a/mert/ScoreData.cpp
+++ b/mert/ScoreData.cpp
@@ -7,6 +7,8 @@
  */
 
 #include "ScoreData.h"
+
+#include <fstream>
 #include "Scorer.h"
 #include "Util.h"
 #include "FileStream.h"
@@ -21,34 +23,40 @@ ScoreData::ScoreData(Scorer* scorer) :
   // TRACE_ERR("ScoreData: m_num_scores: " << m_num_scores << std::endl);
 }
 
-void ScoreData::save(std::ofstream& outFile, bool bin)
+void ScoreData::save(ostream* os, bool bin)
 {
-  for (scoredata_t::iterator i = m_array.begin(); i != m_array.end(); ++i) {
-    i->save(outFile, m_score_type, bin);
+  for (scoredata_t::iterator i = m_array.begin();
+       i != m_array.end(); ++i) {
+    i->save(os, m_score_type, bin);
   }
 }
 
-void ScoreData::save(const std::string &file, bool bin)
+void ScoreData::save(const string &file, bool bin)
 {
   if (file.empty()) return;
-  TRACE_ERR("saving the array into " << file << std::endl);
+  TRACE_ERR("saving the array into " << file << endl);
 
   // matches a stream with a file. Opens the file.
-  std::ofstream outFile(file.c_str(), std::ios::out);
-  save(outFile, bin);
-  outFile.close();
+  ofstream ofs(file.c_str(), ios::out);
+  ostream* os = &ofs;
+  save(os, bin);
+  ofs.close();
 }
 
-void ScoreData::load(ifstream& inFile)
+void ScoreData::save(bool bin) {
+  save(&cout, bin);
+}
+
+void ScoreData::load(istream* is)
 {
   ScoreArray entry;
 
-  while (!inFile.eof()) {
-    if (!inFile.good()) {
-      std::cerr << "ERROR ScoreData::load inFile.good()" << std::endl;
+  while (!is->eof()) {
+    if (!is->good()) {
+      cerr << "ERROR ScoreData::load inFile.good()" << endl;
     }
     entry.clear();
-    entry.load(inFile);
+    entry.load(is);
     if (entry.size() == 0) {
       break;
     }
@@ -56,15 +64,16 @@ void ScoreData::load(ifstream& inFile)
   }
 }
 
-void ScoreData::load(const std::string &file)
+void ScoreData::load(const string &file)
 {
-  TRACE_ERR("loading score data from " << file << std::endl);
-  inputfilestream inFile(file); // matches a stream with a file. Opens the file
-  if (!inFile) {
+  TRACE_ERR("loading score data from " << file << endl);
+  inputfilestream input_stream(file); // matches a stream with a file. Opens the file
+  if (!input_stream) {
     throw runtime_error("Unable to open score file: " + file);
   }
-  load((ifstream&) inFile);
-  inFile.close();
+  istream* is = &input_stream;
+  load(is);
+  input_stream.close();
 }
 
 void ScoreData::add(ScoreArray& e)
@@ -79,7 +88,7 @@ void ScoreData::add(ScoreArray& e)
   }
 }
 
-void ScoreData::add(const ScoreStats& e, const std::string& sent_idx)
+void ScoreData::add(const ScoreStats& e, const string& sent_idx)
 {
   if (exists(sent_idx)) { // array at position e.getIndex() already exists
     // Enlarge array at position e.getIndex()
diff --git a/mert/ScoreData.h b/mert/ScoreData.h
index 475ecb1ca..082cd0cc6 100644
--- a/mert/ScoreData.h
+++ b/mert/ScoreData.h
@@ -9,7 +9,7 @@
 #ifndef MERT_SCORE_DATA_H_
 #define MERT_SCORE_DATA_H_
 
-#include <fstream>
+#include <iostream>
 #include <vector>
 #include <stdexcept>
 #include <string>
@@ -86,12 +86,10 @@ public:
   }
 
   void save(const std::string &file, bool bin=false);
-  void save(ofstream& outFile, bool bin=false);
-  inline void save(bool bin=false) {
-    save("/dev/stdout", bin);
-  }
+  void save(std::ostream* os, bool bin=false);
+  void save(bool bin=false);
 
-  void load(ifstream& inFile);
+  void load(std::istream* is);
   void load(const std::string &file);
 
   bool check_consistency() const;
diff --git a/mert/ScoreStats.cpp b/mert/ScoreStats.cpp
index bc0bb5804..e6c111d5d 100644
--- a/mert/ScoreStats.cpp
+++ b/mert/ScoreStats.cpp
@@ -67,7 +67,7 @@ void ScoreStats::add(ScoreStatsType v)
   m_array[m_entries++]=v;
 }
 
-void ScoreStats::set(const std::string& str)
+void ScoreStats::set(const string& str)
 {
   reset();
   vector<string> out;
@@ -78,46 +78,51 @@ void ScoreStats::set(const std::string& str)
   }
 }
 
-void ScoreStats::loadbin(std::ifstream& inFile)
+void ScoreStats::loadbin(istream* is)
 {
-  inFile.read((char*)m_array, GetArraySizeWithBytes());
+  is->read(reinterpret_cast<char*>(m_array),
+           static_cast<streamsize>(GetArraySizeWithBytes()));
 }
 
-void ScoreStats::loadtxt(std::ifstream& inFile)
+void ScoreStats::loadtxt(istream* is)
 {
-  std::string theString;
-  std::getline(inFile, theString);
-  set(theString);
+  string line;
+  getline(*is, line);
+  set(line);
 }
 
-void ScoreStats::loadtxt(const std::string &file)
+void ScoreStats::loadtxt(const string &file)
 {
-//      TRACE_ERR("loading the stats from " << file << std::endl);
-
-  std::ifstream inFile(file.c_str(), std::ios::in); // matches a stream with a file. Opens the file
-
-  loadtxt(inFile);
+  ifstream ifs(file.c_str(), ios::in); // matches a stream with a file. Opens the file
+  if (!ifs) {
+    cerr << "Failed to open " << file << endl;
+    exit(1);
+  }
+  istream* is = &ifs;
+  loadtxt(is);
 }
 
 
-void ScoreStats::savetxt(const std::string &file)
+void ScoreStats::savetxt(const string &file)
 {
-//      TRACE_ERR("saving the stats into " << file << std::endl);
-
-  std::ofstream outFile(file.c_str(), std::ios::out); // matches a stream with a file. Opens the file
-
-  savetxt(outFile);
+  ofstream ofs(file.c_str(), ios::out); // matches a stream with a file. Opens the file
+  ostream* os = &ofs;
+  savetxt(os);
 }
 
-
-void ScoreStats::savetxt(std::ofstream& outFile)
+void ScoreStats::savetxt(ostream* os)
 {
-  outFile << *this;
+  *os << *this;
 }
 
-void ScoreStats::savebin(std::ofstream& outFile)
+void ScoreStats::savetxt() {
+  savetxt(&cout);
+}
+
+void ScoreStats::savebin(ostream* os)
 {
-  outFile.write((char*)m_array, GetArraySizeWithBytes());
+  os->write(reinterpret_cast<char*>(m_array),
+            static_cast<streamsize>(GetArraySizeWithBytes()));
 }
 
 ostream& operator<<(ostream& o, const ScoreStats& e)
diff --git a/mert/ScoreStats.h b/mert/ScoreStats.h
index dc17de82e..c5dbcbbae 100644
--- a/mert/ScoreStats.h
+++ b/mert/ScoreStats.h
@@ -81,15 +81,13 @@ public:
   inline size_t available() const { return m_available_size; }
 
   void savetxt(const std::string &file);
-  void savetxt(ofstream& outFile);
-  void savebin(ofstream& outFile);
-  inline void savetxt() {
-    savetxt("/dev/stdout");
-  }
+  void savetxt(ostream* os);
+  void savebin(ostream* os);
+  void savetxt();
 
   void loadtxt(const std::string &file);
-  void loadtxt(ifstream& inFile);
-  void loadbin(ifstream& inFile);
+  void loadtxt(istream* is);
+  void loadbin(istream* is);
 
   /**
    * Write the whole object to a stream.