diff --git a/CMake/CMakeLists.txt b/CMake/CMakeLists.txt
index dc7bdcaf..92525b05 100644
--- a/CMake/CMakeLists.txt
+++ b/CMake/CMakeLists.txt
@@ -9,28 +9,30 @@ find_package(Boost 1.55 REQUIRED
              COMPONENTS python iostreams serialization unit_test_framework)
 find_package(PythonLibs)
 find_package(Numpy) # optional
-find_package(ROOT) # only used in one of the tests
 
-include_directories(include ${Boost_INCLUDE_DIRS} ${PYTHON_INCLUDE_DIRS})
+include_directories(include ${Boost_INCLUDE_DIRS})
 add_definitions(-DBOOST_TEST_DYN_LINK) # for unit_test_framework
 set(LIBRARIES stdc++ ${Boost_LIBRARIES})
 
-if(Boost_PYTHON_FOUND)
+if(Boost_PYTHON_FOUND AND PYTHONLIBS_FOUND)
+  set(USE_PYTHON True)
+  include_directories(${PYTHON_INCLUDE_DIRS})
   LIST(APPEND LIBRARIES ${PYTHON_LIBRARIES})
+  add_definitions(-DUSE_PYTHON)  
+
+  if(NUMPY_FOUND)
+    include_directories(${NUMPY_INCLUDE_DIR})
+    add_definitions(-DUSE_NUMPY)
+  endif()
 endif()
 
-if(NUMPY_FOUND)
-  include_directories(${NUMPY_INCLUDE_DIR})
-  add_definitions(-DUSE_NUMPY)
-endif()
-
+# core library
 add_library(histogram SHARED
   src/axis.cpp
   src/histogram_base.cpp
-  src/nhistogram.cpp
+  src/histogram.cpp
   src/nstore.cpp
   src/zero_suppression.cpp
-  # src/whistogram.cpp
 )
 target_link_libraries(histogram ${LIBRARIES})
 
@@ -41,21 +43,24 @@ else()
   target_compile_options(histogram PUBLIC "-O3 -fomit-frame-pointer -mtune=generic")
 endif()
 
-if(Boost_PYTHON_FOUND)
+# python bindings
+if(USE_PYTHON)
   add_library(pyhistogram MODULE
     src/python/module.cpp
     src/python/histogram_base.cpp
-    src/python/nhistogram.cpp
+    src/python/histogram.cpp
   )
   target_link_libraries(pyhistogram histogram ${LIBRARIES})
   set_target_properties(pyhistogram PROPERTIES OUTPUT_NAME "histogram" PREFIX "" SUFFIX ".so")
 endif()
 
+# examples
 add_executable(sizeof
   examples/sizeof.cpp
 )
 target_link_libraries(sizeof ${LIBRARIES})
 
+find_package(ROOT) # only used in speed comparison
 if(ROOT_FOUND)
   add_executable(nhistogram_speed
                  examples/speed_vs_root.cpp)
diff --git a/examples/speed_vs_root.cpp b/examples/speed_vs_root.cpp
index 6c173313..7faf1a2d 100644
--- a/examples/speed_vs_root.cpp
+++ b/examples/speed_vs_root.cpp
@@ -1,4 +1,4 @@
-#include <boost/histogram/nhistogram.hpp>
+#include <boost/histogram/histogram.hpp>
 #include <boost/histogram/axis.hpp>
 #include <boost/random.hpp>
 #include <boost/array.hpp>
@@ -51,7 +51,7 @@ void compare_1d(unsigned n)
     t = clock() - t;
     best_root = std::min(best_root, double(t) / CLOCKS_PER_SEC);
 
-    nhistogram h(regular_axis(100, 0, 1));
+    histogram h(regular_axis(100, 0, 1));
     t = clock();
     for (unsigned i = 0; i < n; ++i)
       h.fill(r[i]);
@@ -80,7 +80,7 @@ void compare_3d(unsigned n)
     t = clock() - t;
     best_root = std::min(best_root, double(t) / CLOCKS_PER_SEC);
 
-    nhistogram h(regular_axis(100, 0, 1),
+    histogram h(regular_axis(100, 0, 1),
                  regular_axis(100, 0, 1),
                  regular_axis(100, 0, 1));
     t = clock();
@@ -118,7 +118,7 @@ void compare_6d(unsigned n)
     t = clock() - t;
     best_root = std::min(best_root, double(t) / CLOCKS_PER_SEC);
 
-    nhistogram h(regular_axis(10, 0, 1),
+    histogram h(regular_axis(10, 0, 1),
                  regular_axis(10, 0, 1),
                  regular_axis(10, 0, 1),
                  regular_axis(10, 0, 1),
diff --git a/include/boost/histogram/detail/nstore.hpp b/include/boost/histogram/detail/nstore.hpp
index c5964a87..5e52a719 100644
--- a/include/boost/histogram/detail/nstore.hpp
+++ b/include/boost/histogram/detail/nstore.hpp
@@ -1,10 +1,12 @@
-#ifndef _BOOST_HISTOGRAM_NSTORE_HPP_
-#define _BOOST_HISTOGRAM_NSTORE_HPP_
+#ifndef _BOOST_HISTOGRAM_DETAIL_NSTORE_HPP_
+#define _BOOST_HISTOGRAM_DETAIL_NSTORE_HPP_
 
+#include <boost/histogram/detail/wtype.hpp>
+#include <boost/histogram/detail/zero_suppression.hpp>
 #include <boost/serialization/access.hpp>
 #include <boost/serialization/array.hpp>
-#include <boost/histogram/detail/zero_suppression.hpp>
 #include <boost/cstdint.hpp>
+#include <boost/assert.hpp>
 #include <cstdlib>
 #include <cstring>
 #include <limits>
@@ -20,7 +22,6 @@ class nstore {
 public:
   typedef uintptr_t size_type;
 
-public:
   nstore();
   nstore(const nstore&);
   nstore(size_type, unsigned d = sizeof(uint8_t));
@@ -30,11 +31,12 @@ public:
   nstore& operator+=(const nstore&);
   bool operator==(const nstore&) const;
 
-  uint64_t read(size_type) const;
-  void write(size_type, uint64_t);
-
   inline void increase(size_type i) {
     switch (depth_) {
+      case sizeof(wtype): {
+        wtype& b = ((wtype*)buffer_)[i];
+        b += 1.0;        
+      }
       #define BOOST_HISTOGRAM_NSTORE_INC(T)     \
       case sizeof(T): {                         \
         T& b = ((T*)buffer_)[i];                \
@@ -51,6 +53,14 @@ public:
     }
   }
 
+  inline void increase(size_type i, double w) {
+    assert(depth_ == sizeof(wtype));
+    ((wtype*)buffer_)[i] += w;
+  }
+
+  double value(size_type) const;
+  double variance(size_type) const;
+
   const void* buffer() const { return buffer_; }
   unsigned depth() const { return depth_; }
 
@@ -62,8 +72,24 @@ private:
   void create();
   void destroy();
   void grow();
+  void wconvert();
 
-  uint64_t max_count() const;
+  uint64_t max_count() const
+  {
+    switch (depth_) {
+      #define BOOST_HISTOGRAM_NSTORE_CASE(T) \
+      case sizeof(T): return std::numeric_limits<T>::max()
+      BOOST_HISTOGRAM_NSTORE_CASE(uint8_t);
+      BOOST_HISTOGRAM_NSTORE_CASE(uint16_t);
+      BOOST_HISTOGRAM_NSTORE_CASE(uint32_t);
+      BOOST_HISTOGRAM_NSTORE_CASE(uint64_t);
+      #undef BOOST_HISTOGRAM_NSTORE_CASE
+      default: assert(!"invalid depth");
+    }
+    return 0;
+  }
+
+  uint64_t ivalue(size_type) const;
 
   friend class serialization::access;
   template <class Archive>
@@ -81,26 +107,50 @@ private:
       throw std::bad_alloc();
 
     if (Archive::is_saving::value) {
-      std::vector<char> buf;
-      if (zero_suppression_encode(buf, size_ * depth_,
-                                          (char*)buffer_, size_ * depth_)) {
-        bool is_zero_suppressed = true;
-        ar & is_zero_suppressed;
-        ar & buf;
-      } else {
-        bool is_zero_suppressed = false;
-        ar & is_zero_suppressed;
-        ar & serialization::make_array((char*)buffer_, size_ * depth_);
+      switch (depth_) {
+        #define BOOST_HISTOGRAM_NSTORE_SAVE(T) \
+        case sizeof(T): {                      \
+          std::vector<T> buf;                  \
+          if (zero_suppression_encode<T>(buf, (T*)buffer_, size_)) { \
+            bool is_zero_suppressed = true;    \
+            ar & is_zero_suppressed;           \
+            ar & buf;                          \
+          } else {                             \
+            bool is_zero_suppressed = false;   \
+            ar & is_zero_suppressed;           \
+            ar & serialization::make_array((T*)buffer_, size_); \
+          }                                    \
+        } break
+        BOOST_HISTOGRAM_NSTORE_SAVE(uint8_t);
+        BOOST_HISTOGRAM_NSTORE_SAVE(uint16_t);
+        BOOST_HISTOGRAM_NSTORE_SAVE(uint32_t);
+        BOOST_HISTOGRAM_NSTORE_SAVE(uint64_t);
+        BOOST_HISTOGRAM_NSTORE_SAVE(wtype);
+        #undef BOOST_HISTOGRAM_NSTORE_SAVE
+        default: assert(!"invalid depth");
       }
-    } else {
+    }
+
+    if (Archive::is_loading::value) {
       bool is_zero_suppressed = false;
       ar & is_zero_suppressed;
-      if (is_zero_suppressed) {
-        std::vector<char> buf;
-        ar & buf;
-        zero_suppression_decode((char*)buffer_, size_ * depth_, buf);
-      } else {
-        ar & serialization::make_array((char*)buffer_, size_ * depth_);
+      switch (depth_) {
+        #define BOOST_HISTOGRAM_NSTORE_LOAD(T) \
+        case sizeof(T):                        \
+        if (is_zero_suppressed) {              \
+          std::vector<T> buf;                  \
+          ar & buf;                            \
+          zero_suppression_decode<T>((T*)buffer_, size_, buf); \
+        } else {                               \
+          ar & serialization::make_array((T*)buffer_, size_); \
+        } break
+        BOOST_HISTOGRAM_NSTORE_LOAD(uint8_t);
+        BOOST_HISTOGRAM_NSTORE_LOAD(uint16_t);
+        BOOST_HISTOGRAM_NSTORE_LOAD(uint32_t);
+        BOOST_HISTOGRAM_NSTORE_LOAD(uint64_t);
+        BOOST_HISTOGRAM_NSTORE_LOAD(wtype);
+        #undef BOOST_HISTOGRAM_NSTORE_LOAD
+        default: assert(!"invalid depth");
       }
     }
   }
diff --git a/include/boost/histogram/detail/wtype.hpp b/include/boost/histogram/detail/wtype.hpp
new file mode 100644
index 00000000..25962f04
--- /dev/null
+++ b/include/boost/histogram/detail/wtype.hpp
@@ -0,0 +1,47 @@
+#ifndef _BOOST_HISTOGRAM_DETAIL_WTYPE_HPP_
+#define _BOOST_HISTOGRAM_DETAIL_WTYPE_HPP_
+
+#include <boost/cstdint.hpp>
+#include <ostream>
+
+namespace boost {
+namespace histogram {
+namespace detail {
+
+struct wtype {
+  double w, w2;
+  wtype() : w(0), w2(0) {}  
+  wtype(const wtype& o) : w(o.w), w2(o.w2) {}
+  wtype(uint64_t i) : w(i), w2(i) {}
+  wtype& operator+=(const wtype& o)
+  { w += o.w; w2 += o.w2; return *this; }
+  wtype& operator+=(double v)
+  { w += v; w2 += v*v; return *this; }
+  wtype& operator=(uint64_t i)
+  { w = i; w2 = i; return *this; }
+  bool operator==(uint64_t i) const
+  { return w == i; }
+  bool operator!=(uint64_t i) const
+  { return w != i; }
+  bool operator==(const wtype& o) const
+  { return w == o.w && w2 == o.w2; }
+  bool operator!=(const wtype& o) const
+  { return w != o.w || w2 != o.w2; }
+  template <class Archive>
+  void serialize(Archive& ar, unsigned version)
+  { ar & w; ar & w2; }
+};
+
+static
+inline
+std::ostream& operator<<(std::ostream& os, const wtype& w)
+{
+  os << '(' << w.w << ',' << w.w2 << ')';
+  return os;
+}
+
+}
+}
+}
+
+#endif
diff --git a/include/boost/histogram/detail/zero_suppression.hpp b/include/boost/histogram/detail/zero_suppression.hpp
index 83be148b..b2fc3a03 100644
--- a/include/boost/histogram/detail/zero_suppression.hpp
+++ b/include/boost/histogram/detail/zero_suppression.hpp
@@ -1,20 +1,80 @@
 #ifndef _BOOST_HISTOGRAM_DETAIL_ZERO_SUPPRESSION_HPP_
 #define _BOOST_HISTOGRAM_DETAIL_ZERO_SUPPRESSION_HPP_
 
-#include <cstddef>
+#include <boost/cstdint.hpp>
+#include <boost/histogram/detail/wtype.hpp>
+#include <limits>
 #include <vector>
 
 namespace boost {
 namespace histogram {
 namespace detail {
 
+template <typename T>
 bool
-zero_suppression_encode(std::vector<char>& output, std::size_t output_max,
-                        const char* input, std::size_t input_len);
+zero_suppression_encode(std::vector<T>& output, const T* input,
+                        uintptr_t size)
+{
+    #define BOOST_HISTOGRAM_ZERO_SUPPRESSION_FILL { \
+        if ((size - output.size()) < 2) \
+            return false;                     \
+        output.push_back(0);                  \
+        output.push_back(nzero);              \
+        nzero = 0;                            \
+    }
 
+    const T* input_end = input + size;
+    T nzero = 0;
+    for (; input != input_end; ++input) {
+        if (*input != 0) {
+            if (nzero)
+                BOOST_HISTOGRAM_ZERO_SUPPRESSION_FILL
+            if (output.size() == size)
+                return false;
+            output.push_back(*input);
+        }
+        else {
+            ++nzero;
+            if (nzero == 0) // overflowed to zero
+                BOOST_HISTOGRAM_ZERO_SUPPRESSION_FILL
+        }
+    }
+    if (nzero)
+        BOOST_HISTOGRAM_ZERO_SUPPRESSION_FILL
+    return true;
+}
+
+template <typename T>
 void
-zero_suppression_decode(char* output, std::size_t output_len,
-                        const std::vector<char>& input);
+zero_suppression_decode(T* output, uintptr_t size,
+                        const std::vector<T>& input)
+{
+    const T* inp = &input[0];
+    const T* output_end = output + size;
+    while (output != output_end) {
+        *output = *inp;
+        if (*inp == 0) {
+            const uintptr_t nzero = *(++inp);
+            for (T j = 1; j != nzero; ++j) {
+                *(++output) = 0;
+                if (output == output_end)
+                    return;
+            }
+        }
+        ++inp;
+        ++output;
+    }
+}
+
+template <>
+void
+zero_suppression_decode(wtype* output, uintptr_t size,
+                        const std::vector<wtype>& input);
+
+template <>
+bool
+zero_suppression_encode(std::vector<wtype>& output, const wtype* input,
+                        uintptr_t size);
 
 }
 }
diff --git a/include/boost/histogram/nhistogram.hpp b/include/boost/histogram/histogram.hpp
similarity index 55%
rename from include/boost/histogram/nhistogram.hpp
rename to include/boost/histogram/histogram.hpp
index 788023fd..15ea3cae 100644
--- a/include/boost/histogram/nhistogram.hpp
+++ b/include/boost/histogram/histogram.hpp
@@ -1,5 +1,5 @@
-#ifndef _BOOST_HISTOGRAM_NHISTOGRAM_HPP_
-#define _BOOST_HISTOGRAM_NHISTOGRAM_HPP_
+#ifndef _BOOST_HISTOGRAM_HISTOGRAM_HPP_
+#define _BOOST_HISTOGRAM_HISTOGRAM_HPP_
 
 #include <boost/histogram/axis.hpp>
 #include <boost/histogram/histogram_base.hpp>
@@ -9,28 +9,27 @@
 #include <boost/serialization/base_object.hpp>
 #include <boost/shared_ptr.hpp>
 #include <boost/assert.hpp>
-#include <boost/python/dict.hpp>
 
 namespace boost {
 namespace histogram {
 
-class nhistogram : public histogram_base {
+class histogram : public histogram_base {
 public:
-  nhistogram() {}
+  histogram() {}
 
-  nhistogram(const nhistogram& o) :
+  histogram(const histogram& o) :
     histogram_base(o),
     data_(o.data_)
   {}
 
   explicit
-  nhistogram(const axes_type& axes) :
+  histogram(const axes_type& axes) :
     histogram_base(axes),
     data_(field_count())
   {}
 
 #define BOOST_NHISTOGRAM_CTOR(z, n, unused)                        \
-  nhistogram( BOOST_PP_ENUM_PARAMS_Z(z, n, const axis_type& a) ) : \
+  histogram( BOOST_PP_ENUM_PARAMS_Z(z, n, const axis_type& a) ) : \
     histogram_base( BOOST_PP_ENUM_PARAMS_Z(z, n, a) ),             \
     data_(field_count())                                           \
   {}
@@ -73,12 +72,43 @@ BOOST_PP_REPEAT_FROM_TO(1, BOOST_HISTOGRAM_AXIS_LIMIT, BOOST_NHISTOGRAM_CTOR, ni
 // generates fill functions taking 1 to AXIS_LIMT arguments
 BOOST_PP_REPEAT_FROM_TO(1, BOOST_HISTOGRAM_AXIS_LIMIT, BOOST_NHISTOGRAM_FILL, nil)  
 
+  template <typename Container>
+  inline
+  void wfill(const Container& v, double w)
+  {
+    BOOST_ASSERT(v.size() == dim());
+    const size_type k = pos(v);
+    if (k != uintmax_t(-1))
+      data_.increase(k, w);
+  }
+
+  // C-style call
+  inline
+  void wfill(unsigned n, const double* v, double w)
+  {
+    BOOST_ASSERT(n == dim());
+    const size_type k = pos(v);
+    if (k != uintmax_t(-1))
+      data_.increase(k, w);
+  }
+
+#define BOOST_NHISTOGRAM_WFILL(z, n, unused)                     \
+  inline                                                         \
+  void wfill( BOOST_PP_ENUM_PARAMS_Z(z, n, double x), double w ) \
+  {                                                              \
+    const double buffer[n] = { BOOST_PP_ENUM_PARAMS(n, x) };     \
+    wfill(n, buffer, w); /* size is checked here */              \
+  }
+
+// generates wfill functions taking 1 to AXIS_LIMT arguments
+BOOST_PP_REPEAT_FROM_TO(1, BOOST_HISTOGRAM_AXIS_LIMIT, BOOST_NHISTOGRAM_WFILL, nil)  
+
   template <typename Container>
   double value(const Container& idx)
     const
   {
     BOOST_ASSERT(idx.size() == dim());
-    return data_.read(linearize(idx));
+    return data_.value(linearize(idx));
   }
 
   // C-style call
@@ -86,7 +116,7 @@ BOOST_PP_REPEAT_FROM_TO(1, BOOST_HISTOGRAM_AXIS_LIMIT, BOOST_NHISTOGRAM_FILL, ni
     const
   {
     BOOST_ASSERT(n == dim());
-    return data_.read(linearize(idx));
+    return data_.value(linearize(idx));
   }
 
 #define BOOST_NHISTOGRAM_VALUE(z, n, unused)                \
@@ -100,11 +130,38 @@ BOOST_PP_REPEAT_FROM_TO(1, BOOST_HISTOGRAM_AXIS_LIMIT, BOOST_NHISTOGRAM_FILL, ni
 // generates value functions taking 1 to AXIS_LIMT arguments
 BOOST_PP_REPEAT_FROM_TO(1, BOOST_HISTOGRAM_AXIS_LIMIT, BOOST_NHISTOGRAM_VALUE, nil)  
 
-  bool operator==(const nhistogram& o) const 
+  template <typename Container>
+  double variance(const Container& idx)
+    const
+  {
+    BOOST_ASSERT(idx.size() == dim());
+    return data_.variance(linearize(idx));
+  }
+
+  // C-style call
+  double variance(unsigned n, const int* idx)
+    const
+  {
+    BOOST_ASSERT(n == dim());
+    return data_.variance(linearize(idx));
+  }
+
+#define BOOST_NHISTOGRAM_VARIANCE(z, n, unused)             \
+  double variance( BOOST_PP_ENUM_PARAMS_Z(z, n, int i) )    \
+    const                                                   \
+  {                                                         \
+    const int idx[n] = { BOOST_PP_ENUM_PARAMS_Z(z, n, i) }; \
+    return variance(n, idx); /* size is checked here */     \
+  }
+
+// generates variance functions taking 1 to AXIS_LIMT arguments
+BOOST_PP_REPEAT_FROM_TO(1, BOOST_HISTOGRAM_AXIS_LIMIT, BOOST_NHISTOGRAM_VARIANCE, nil)  
+
+  bool operator==(const histogram& o) const 
   { return histogram_base::operator==(o) &&
            data_ == o.data_; }
 
-  nhistogram& operator+=(const nhistogram& o)
+  histogram& operator+=(const histogram& o)
   { data_ += o.data_; return *this; }
 
 private:
@@ -118,11 +175,11 @@ private:
     ar & data_;
   }
 
-  friend python::dict nhistogram_array_interface(nhistogram&);
+  friend class buffer_access;
 };
 
-nhistogram operator+(const nhistogram& a, const nhistogram& b) {
-  nhistogram result(a);
+histogram operator+(const histogram& a, const histogram& b) {
+  histogram result(a);
   return result += b;
 }
 
diff --git a/include/boost/histogram/wstore.hpp b/include/boost/histogram/wstore.hpp
deleted file mode 100644
index 20cf767c..00000000
--- a/include/boost/histogram/wstore.hpp
+++ /dev/null
@@ -1,110 +0,0 @@
-#include <cstdlib>
-#include <cstring>
-#include <stdexcept>
-#include <boost/serialization/array.hpp>
-
-class wstore {
-public:
-  typedef boost::uintmax_t size_type;
-  struct wcount { double w_, w2_; };
-
-private:
-  size_type size_;
-  double* buffer_;
-
-  friend class boost::serialization::access;
-  template <class Archive>
-  void serialize(Archive & ar, unsigned version) {
-    using boost::serialization::make_array;
-    size_type s = size_;
-    ar & make_nvp("size", size_);
-    if (s != size_) {
-      destroy();
-      create();
-    }
-    ar & make_nvp("data",                    \
-                  make_array(buffer_, size_ * 2));
-  }
-
-  void
-  create() {
-    buffer_ = (double*)std::calloc(size_, sizeof(wcount));
-  }
-
-  void
-  destroy() {
-    free(buffer_);
-    buffer_ = 0;
-  }
-
-public:
-  wstore()
-    : size_(0), buffer_(0)
-  {}
-
-  wstore(size_type n)
-    : size_(n)
-  {
-    create();
-  }
-
-  wstore(const wstore& other)
-    : size_(other.size_)
-  {
-    create();
-    *this = other;
-  }
-
-  ~wstore() { destroy(); }
-
-  wstore&
-  operator=(const wstore& other)
-  {
-    if (size_ != other.size_) {
-      destroy();
-      size_ = other.size_;
-      create();
-    }
-    std::memcpy(buffer_, other.buffer_, size_ * sizeof(wcount));
-    return *this;
-  }
-
-  inline
-  wcount&
-  operator[](size_type i)
-  {
-    return *((wcount*)buffer_ + i);
-  }
-
-  inline
-  const wcount&
-  operator[](size_type i) const
-  {
-    return *((wcount*)buffer_ + i);
-  }
-
-  wstore&
-  operator+=(const wstore& other) {
-    if (size_ != other.size_)
-      throw std::logic_error("sizes do not match");
-
-    for (size_type i = 0; i < (size_ * 2); ++i)
-      buffer_[i] += other.buffer_[i];
-    return *this;
-  }
-
-  bool
-  operator==(const wstore& other) const {
-    if (size_ != other.size_)
-      return false;
-
-    for (size_type i = 0; i < (size_ * 2); ++i)
-      if (buffer_[i] != other.buffer_[i])
-        return false;
-
-    return true;
-  }
-
-  inline size_type size() const { return size_; }
-  inline const double* buffer() const { return buffer_; }
-};
diff --git a/src/nhistogram.cpp b/src/histogram.cpp
similarity index 67%
rename from src/nhistogram.cpp
rename to src/histogram.cpp
index 97a5c3f5..4e9f4a89 100644
--- a/src/nhistogram.cpp
+++ b/src/histogram.cpp
@@ -1,16 +1,16 @@
-#include <boost/histogram/nhistogram.hpp>
+#include <boost/histogram/histogram.hpp>
 #include <ostream>
 
 namespace boost {
 namespace histogram {
 
 double
-nhistogram::sum()
+histogram::sum()
     const
 {
     double result = 0.0;
     for (size_type i = 0, n = field_count(); i < n; ++i)
-      result += data_.read(i);
+      result += data_.value(i);
     return result;
 }
 
diff --git a/src/nstore.cpp b/src/nstore.cpp
index 67cc5239..fc09a738 100644
--- a/src/nstore.cpp
+++ b/src/nstore.cpp
@@ -50,8 +50,42 @@ nstore::operator+=(const nstore& o)
 {
   if (size_ != o.size_)
     throw std::logic_error("sizes do not match");
-  for (size_type i = 0; i < size_; ++i)
-    write(i, read(i) + o.read(i));
+
+  if (depth_ != o.depth_) {
+    if (o.depth_ == sizeof(wtype))
+      wconvert();
+    else
+      while (depth_ < o.depth_)
+        grow();
+  }
+
+  if (depth_ == sizeof(wtype)) {
+    for (size_type i = 0; i < size_; ++i)
+      ((wtype*)buffer_)[i] += ((wtype*)o.buffer_)[i];
+  }
+  else {
+    size_type i = 0;
+    while (i < size_) {
+      const uint64_t oi = o.ivalue(i);
+      switch (depth_) {
+        #define BOOST_HISTOGRAM_NSTORE_ADD(T)              \
+        case sizeof(T): {                                  \
+          T& b = ((T*)buffer_)[i];                         \
+          if ((std::numeric_limits<T>::max() - b) >= oi) { \
+            b += oi;                                       \
+            ++i;                                           \
+            break;                                         \
+          } else grow(); /* add fall through */            \
+        }
+        BOOST_HISTOGRAM_NSTORE_ADD(uint8_t);
+        BOOST_HISTOGRAM_NSTORE_ADD(uint16_t);
+        BOOST_HISTOGRAM_NSTORE_ADD(uint32_t);
+        BOOST_HISTOGRAM_NSTORE_ADD(uint64_t);
+        #undef BOOST_HISTOGRAM_NSTORE_ADD
+        default: assert(!"invalid depth");
+      }
+    }
+  }
   return *this;
 }
 
@@ -64,42 +98,31 @@ nstore::operator==(const nstore& o)
   return std::memcmp(buffer_, o.buffer_, size_ * depth_) == 0;
 }
 
-uint64_t
-nstore::read(size_type i)
+double
+nstore::value(size_type i)
+  const
+{
+  if (depth_ == sizeof(wtype))
+    return ((wtype*)buffer_)[i].w;
+  return ivalue(i);
+}
+
+double
+nstore::variance(size_type i)
   const
 {
   switch (depth_) {
-    #define BOOST_HISTOGRAM_NSTORE_READ(T) \
+    case sizeof(wtype): return ((wtype*)buffer_)[i].w2;
+    #define BOOST_HISTOGRAM_NSTORE_VARIANCE(T) \
     case sizeof(T): return ((T*)buffer_)[i]
-    BOOST_HISTOGRAM_NSTORE_READ(uint8_t);
-    BOOST_HISTOGRAM_NSTORE_READ(uint16_t);
-    BOOST_HISTOGRAM_NSTORE_READ(uint32_t);
-    BOOST_HISTOGRAM_NSTORE_READ(uint64_t);
-    #undef BOOST_HISTOGRAM_NSTORE_READ
-    default: assert(!"invalid depth");
-  }
-  return 0;
-}
-
-void
-nstore::write(size_type i, uint64_t v)
-{
-  const uint64_t vmax = max_count();
-  while (vmax < v) grow();
-
-  switch (depth_) {
-    #define BOOST_HISTOGRAM_NSTORE_WRITE(T) \
-    case sizeof(T): {                       \
-      ((T*)buffer_)[i] = v;                 \
-      break;                                \
-    }
-    BOOST_HISTOGRAM_NSTORE_WRITE(uint8_t);
-    BOOST_HISTOGRAM_NSTORE_WRITE(uint16_t);
-    BOOST_HISTOGRAM_NSTORE_WRITE(uint32_t);
-    BOOST_HISTOGRAM_NSTORE_WRITE(uint64_t);
-    #undef BOOST_HISTOGRAM_NSTORE_WRITE
+    BOOST_HISTOGRAM_NSTORE_VARIANCE(uint8_t);
+    BOOST_HISTOGRAM_NSTORE_VARIANCE(uint16_t);
+    BOOST_HISTOGRAM_NSTORE_VARIANCE(uint32_t);
+    BOOST_HISTOGRAM_NSTORE_VARIANCE(uint64_t);
+    #undef BOOST_HISTOGRAM_NSTORE_VARIANCE
     default: assert(!"invalid depth");
   }
+  return 0.0;
 }
 
 void
@@ -118,17 +141,17 @@ nstore::destroy()
 void
 nstore::grow()
 {
-  if (depth_ == sizeof(uint64_t))
-    throw std::overflow_error("depth > 64 bit is not supported");
-  if (depth_ == 0 || buffer_ == 0)
-    throw std::logic_error("cannot call grow on null buffer");
+  assert(depth_ > 0);
+  assert(depth_ < sizeof(uint64_t));
+  assert(buffer_ != 0);
   buffer_ = std::realloc(buffer_, size_ * 2 * depth_);
   if (!buffer_) throw std::bad_alloc();
+  size_type i = size_;
   switch (depth_) {
-    #define BOOST_HISTOGRAM_NSTORE_GROW(T0, T1)          \
-    case sizeof(T0):                                     \
-    for (size_type i = size_ - 1; i != size_type(-1); --i) \
-      ((T1*)buffer_)[i] = ((T0*)buffer_)[i];             \
+    #define BOOST_HISTOGRAM_NSTORE_GROW(T0, T1) \
+    case sizeof(T0):                            \
+    while (i--)                                 \
+      ((T1*)buffer_)[i] = ((T0*)buffer_)[i];    \
     break
     BOOST_HISTOGRAM_NSTORE_GROW(uint8_t, uint16_t);
     BOOST_HISTOGRAM_NSTORE_GROW(uint16_t, uint32_t);
@@ -138,17 +161,41 @@ nstore::grow()
   depth_ *= 2;
 }
 
+void
+nstore::wconvert()
+{
+  assert(depth_ < sizeof(wtype));
+  buffer_ = std::realloc(buffer_, size_ * sizeof(wtype));
+  if (!buffer_) throw std::bad_alloc();
+  size_type i = size_;
+  switch (depth_) {
+    #define BOOST_HISTOGRAM_NSTORE_CONVERT(T)  \
+    case sizeof(T):                            \
+    while (i--)                                \
+      ((wtype*)buffer_)[i] = ((T*)buffer_)[i]; \
+    break
+    BOOST_HISTOGRAM_NSTORE_CONVERT(uint8_t);
+    BOOST_HISTOGRAM_NSTORE_CONVERT(uint16_t);
+    BOOST_HISTOGRAM_NSTORE_CONVERT(uint32_t);
+    BOOST_HISTOGRAM_NSTORE_CONVERT(uint64_t);
+    #undef BOOST_HISTOGRAM_NSTORE_CONVERT
+    default: break; // no nuthin'
+  }
+  depth_ = sizeof(wtype);
+}
+
 uint64_t
-nstore::max_count()
+nstore::ivalue(size_type i)
   const
 {
   switch (depth_) {
-    #define BOOST_HISTOGRAM_NSTORE_CASE(T) \
-    case sizeof(T): return std::numeric_limits<T>::max()
-    BOOST_HISTOGRAM_NSTORE_CASE(uint8_t);
-    BOOST_HISTOGRAM_NSTORE_CASE(uint16_t);
-    BOOST_HISTOGRAM_NSTORE_CASE(uint32_t);
-    BOOST_HISTOGRAM_NSTORE_CASE(uint64_t);
+    #define BOOST_HISTOGRAM_NSTORE_IVALUE(T) \
+    case sizeof(T): return ((T*)buffer_)[i]
+    BOOST_HISTOGRAM_NSTORE_IVALUE(uint8_t);
+    BOOST_HISTOGRAM_NSTORE_IVALUE(uint16_t);
+    BOOST_HISTOGRAM_NSTORE_IVALUE(uint32_t);
+    BOOST_HISTOGRAM_NSTORE_IVALUE(uint64_t);
+    #undef BOOST_HISTOGRAM_NSTORE_IVALUE
     default: assert(!"invalid depth");
   }
   return 0;
diff --git a/src/python/nhistogram.cpp b/src/python/histogram.cpp
similarity index 76%
rename from src/python/nhistogram.cpp
rename to src/python/histogram.cpp
index cc9e9cc5..7edeaddd 100644
--- a/src/python/nhistogram.cpp
+++ b/src/python/histogram.cpp
@@ -1,10 +1,10 @@
+#include "serialization_suite.hpp"
 #include <boost/histogram/axis.hpp>
-#include <boost/histogram/nhistogram.hpp>
+#include <boost/histogram/histogram.hpp>
 #include <boost/python.hpp>
 #include <boost/python/raw_function.hpp>
 #include <boost/foreach.hpp>
 #include <boost/shared_ptr.hpp>
-#include "serialization_suite.hpp"
 #ifdef USE_NUMPY
 # define NO_IMPORT_ARRAY
 # define PY_ARRAY_UNIQUE_SYMBOL boost_histogram_ARRAY_API
@@ -16,7 +16,7 @@ namespace boost {
 namespace histogram {
 
 python::object
-nhistogram_init(python::tuple args, python::dict kwargs) {
+histogram_init(python::tuple args, python::dict kwargs) {
     using namespace python;
     using python::tuple;
 
@@ -48,24 +48,12 @@ nhistogram_init(python::tuple args, python::dict kwargs) {
     return pyinit(axes);
 }
 
-python::dict
-nhistogram_array_interface(nhistogram& self) {
-    python::list shape;
-    for (unsigned i = 0; i < self.dim(); ++i)
-        shape.append(self.shape(i));
-    python::dict d;
-    d["shape"] = python::tuple(shape);
-    d["typestr"] = python::str("<u") + python::str(self.depth());
-    d["data"] = python::make_tuple((long long)(self.data_.buffer()), false);
-    return d;
-}
-
 python::object
-nhistogram_fill(python::tuple args, python::dict kwargs) {
+histogram_fill(python::tuple args, python::dict kwargs) {
     using namespace python;
 
     const unsigned nargs = len(args);
-    nhistogram& self = extract<nhistogram&>(args[0]);
+    histogram& self = extract<histogram&>(args[0]);
 
 #ifdef USE_NUMPY
     if (nargs == 2) {
@@ -128,7 +116,7 @@ nhistogram_fill(python::tuple args, python::dict kwargs) {
 }
 
 uint64_t
-nhistogram_getitem(const nhistogram& self, python::object oidx) {
+histogram_getitem(const histogram& self, python::object oidx) {
     using namespace python;
 
     if (self.dim() == 1)
@@ -147,26 +135,42 @@ nhistogram_getitem(const nhistogram& self, python::object oidx) {
     return self.value(self.dim(), idx);
 }
 
-void register_nhistogram()
+class buffer_access {
+public:
+    static
+    python::dict
+    histogram_array_interface(histogram& self) {
+        python::list shape;
+        for (unsigned i = 0; i < self.dim(); ++i)
+            shape.append(self.shape(i));
+        python::dict d;
+        d["shape"] = python::tuple(shape);
+        d["typestr"] = python::str("<u") + python::str(self.data_.depth());
+        d["data"] = python::make_tuple((long long)(self.data_.buffer()), false);
+        return d;
+    }
+};
+
+void register_histogram()
 {
     using namespace python;
 
     class_<
-      nhistogram, bases<histogram_base>,
-      shared_ptr<nhistogram>
-    >("nhistogram", no_init)
-        .def("__init__", raw_function(nhistogram_init))
+      histogram, bases<histogram_base>,
+      shared_ptr<histogram>
+    >("histogram", no_init)
+        .def("__init__", raw_function(histogram_init))
         // shadowed C++ ctors
         .def(init<const axes_type&>())
-        .add_property("__array_interface__", nhistogram_array_interface)
-        .def("fill", raw_function(nhistogram_fill))
-        .add_property("depth", &nhistogram::depth)
-        .add_property("sum", &nhistogram::sum)
-        .def("__getitem__", nhistogram_getitem)
+        .add_property("__array_interface__", &buffer_access::histogram_array_interface)
+        .def("fill", raw_function(histogram_fill))
+        .add_property("depth", &histogram::depth)
+        .add_property("sum", &histogram::sum)
+        .def("__getitem__", histogram_getitem)
         .def(self == self)
         .def(self += self)
         .def(self + self)
-        .def_pickle(serialization_suite<nhistogram>())
+        .def_pickle(serialization_suite<histogram>())
         ;
 }
 
diff --git a/src/python/module.cpp b/src/python/module.cpp
index 8b579a7a..66801158 100644
--- a/src/python/module.cpp
+++ b/src/python/module.cpp
@@ -8,7 +8,7 @@
 namespace boost {
 namespace histogram {
   void register_histogram_base();
-  void register_nhistogram();
+  void register_histogram();
 }
 }
 
@@ -18,5 +18,5 @@ BOOST_PYTHON_MODULE(histogram)
   import_array();
 #endif
   boost::histogram::register_histogram_base();
-  boost::histogram::register_nhistogram();
+  boost::histogram::register_histogram();
 }
diff --git a/src/zero_suppression.cpp b/src/zero_suppression.cpp
index 0ac233b1..aa471f7f 100644
--- a/src/zero_suppression.cpp
+++ b/src/zero_suppression.cpp
@@ -4,50 +4,52 @@ namespace boost {
 namespace histogram {
 namespace detail {
 
+template <>
 bool
-zero_suppression_encode(std::vector<char>& output, std::size_t output_max,
-                        const char* input, std::size_t input_len)
+zero_suppression_encode(std::vector<wtype>& output, const wtype* input,
+                        uintptr_t size)
 {
-    #define FILL_OUTPUT {                     \
-        if ((output_max - output.size()) < 2) \
+    #define BOOST_HISTOGRAM_ZERO_SUPPRESSION_FILL { \
+        if ((size - output.size()) < 2) \
             return false;                     \
         output.push_back(0);                  \
         output.push_back(nzero);              \
         nzero = 0;                            \
     }
 
-    const char* input_end = input + input_len;
-    unsigned nzero = 0;
+    const wtype* input_end = input + size;
+    uint32_t nzero = 0;
     for (; input != input_end; ++input) {
         if (*input != 0) {
             if (nzero)
-                FILL_OUTPUT
-            if (output.size() == output_max)
+                BOOST_HISTOGRAM_ZERO_SUPPRESSION_FILL
+            if (output.size() == size)
                 return false;
             output.push_back(*input);
         }
         else {
             ++nzero;
-            if (nzero == 256)
-                FILL_OUTPUT
+            if (nzero == 0) // overflowed to zero
+                BOOST_HISTOGRAM_ZERO_SUPPRESSION_FILL
         }
     }
     if (nzero)
-        FILL_OUTPUT
+        BOOST_HISTOGRAM_ZERO_SUPPRESSION_FILL
     return true;
 }
 
+template <>
 void
-zero_suppression_decode(char* output, std::size_t output_len,
-                        const std::vector<char>& input)
+zero_suppression_decode(wtype* output, uintptr_t size,
+                        const std::vector<wtype>& input)
 {
-    const char* inp = &input[0];
-    const char* output_end = output + output_len;
+    const wtype* inp = &input[0];
+    const wtype* output_end = output + size;
     while (output != output_end) {
         *output = *inp;
         if (*inp == 0) {
-            const char nzero = *(++inp);
-            for (char j = 1; j != nzero; ++j) {
+            const uintptr_t nzero = (++inp)->w;
+            for (uintptr_t j = 1; j != nzero; ++j) {
                 *(++output) = 0;
                 if (output == output_end)
                     return;
diff --git a/test/python_suite_test.py b/test/python_suite_test.py
index b7e5ead6..ab8bfe7c 100755
--- a/test/python_suite_test.py
+++ b/test/python_suite_test.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 import unittest
 from math import pi
-from histogram import nhistogram, regular_axis, polar_axis, \
+from histogram import histogram, regular_axis, polar_axis, \
                       variable_axis, category_axis, integer_axis
 import cPickle
 import StringIO
@@ -299,39 +299,39 @@ class test_integer_axis(unittest.TestCase):
         self.assertEqual(a.index(3), 4)
         self.assertEqual(a.index(4), 4)
 
-class nhistogram_test(unittest.TestCase):
+class histogram_test(unittest.TestCase):
 
     def test_init(self):
-        nhistogram(integer_axis(-1, 1))
+        histogram(integer_axis(-1, 1))
         with self.assertRaises(TypeError):
-            nhistogram(1)
+            histogram(1)
         with self.assertRaises(TypeError):
-            nhistogram("bla")
+            histogram("bla")
         with self.assertRaises(TypeError):
-            nhistogram([])
+            histogram([])
         with self.assertRaises(TypeError):
-            nhistogram(regular_axis)
+            histogram(regular_axis)
         with self.assertRaises(TypeError):
-            nhistogram(regular_axis())
+            histogram(regular_axis())
         with self.assertRaises(TypeError):
-            nhistogram([integer_axis(-1, 1)])
+            histogram([integer_axis(-1, 1)])
         with self.assertRaises(TypeError):
-            nhistogram(integer_axis(-1, 1), unknown_keyword="nh")
+            histogram(integer_axis(-1, 1), unknown_keyword="nh")
 
-        h = nhistogram(integer_axis(-1, 1))
+        h = histogram(integer_axis(-1, 1))
         self.assertEqual(h.dim, 1)
         self.assertEqual(h.axis(0), integer_axis(-1, 1))
         self.assertEqual(h.shape(0), 5)
         self.assertEqual(h.depth, 1)
-        self.assertEqual(nhistogram(integer_axis(-1, 1, uoflow=False)).shape(0), 3)
-        self.assertNotEqual(h, nhistogram(regular_axis(1, -1, 1)))
-        self.assertNotEqual(h, nhistogram(integer_axis(-1, 2)))
-        self.assertNotEqual(h, nhistogram(integer_axis(-1, 1, label="ia")))
-        self.assertNotEqual(h, nhistogram(integer_axis(-1, 1, uoflow=True)))
+        self.assertEqual(histogram(integer_axis(-1, 1, uoflow=False)).shape(0), 3)
+        self.assertNotEqual(h, histogram(regular_axis(1, -1, 1)))
+        self.assertNotEqual(h, histogram(integer_axis(-1, 2)))
+        self.assertNotEqual(h, histogram(integer_axis(-1, 1, label="ia")))
+        self.assertNotEqual(h, histogram(integer_axis(-1, 1, uoflow=True)))
 
     def test_fill_1d(self):
-        h0 = nhistogram(integer_axis(-1, 1, uoflow=False))
-        h1 = nhistogram(integer_axis(-1, 1, uoflow=True))
+        h0 = histogram(integer_axis(-1, 1, uoflow=False))
+        h1 = histogram(integer_axis(-1, 1, uoflow=True))
         for h in (h0, h1):
             with self.assertRaises(StandardError):
                 h.fill()
@@ -363,7 +363,7 @@ class nhistogram_test(unittest.TestCase):
         self.assertEqual(h1[3], 1)
 
     def test_growth(self):
-        h = nhistogram(integer_axis(-1, 1))
+        h = histogram(integer_axis(-1, 1))
         h.fill(-1)
         h.fill(1)
         h.fill(1)
@@ -382,7 +382,7 @@ class nhistogram_test(unittest.TestCase):
 
     def test_fill_2d(self):
         for uoflow in (False, True):
-            h = nhistogram(integer_axis(-1, 1, uoflow=uoflow),
+            h = histogram(integer_axis(-1, 1, uoflow=uoflow),
                            regular_axis(4, -2, 2, uoflow=uoflow))
             h.fill(-1, -2)
             h.fill(-1, -1)
@@ -407,7 +407,7 @@ class nhistogram_test(unittest.TestCase):
 
     def test_add_2d(self):
         for uoflow in (False, True):
-            h = nhistogram(integer_axis(-1, 1, uoflow=uoflow),
+            h = histogram(integer_axis(-1, 1, uoflow=uoflow),
                            regular_axis(4, -2, 2, uoflow=uoflow))
             h.fill(-1, -2)
             h.fill(-1, -1)
@@ -432,7 +432,7 @@ class nhistogram_test(unittest.TestCase):
                     self.assertEqual(h[i, j], 2 * m[i][j])
 
     def test_pickle(self):
-        a = nhistogram(category_axis('A', 'B', 'C'),
+        a = histogram(category_axis('A', 'B', 'C'),
                        integer_axis(0, 3, label='ia'),
                        regular_axis(4, 0.0, 4.0, uoflow=False),
                        variable_axis(0.0, 1.0, 2.0))
@@ -460,7 +460,7 @@ class nhistogram_test(unittest.TestCase):
 
     @unittest.skipUnless("numpy" in globals(), "requires numpy")
     def test_numpy_conversion(self):
-        a = nhistogram(integer_axis(0, 2, uoflow=False))
+        a = histogram(integer_axis(0, 2, uoflow=False))
         for i in xrange(100):
             a.fill(1)
         b = numpy.array(a) # a copy
@@ -481,19 +481,19 @@ class nhistogram_test(unittest.TestCase):
 
     @unittest.skipUnless("numpy" in globals(), "requires numpy")
     def test_fill_with_numpy_array(self):
-        a = nhistogram(integer_axis(0, 2, uoflow=False))
+        a = histogram(integer_axis(0, 2, uoflow=False))
         a.fill(numpy.array([-1, 0, 1, 2, 1, 4]))
         self.assertEqual(a[0], 1)
         self.assertEqual(a[1], 2)
         self.assertEqual(a[2], 1)
-        a = nhistogram(integer_axis(0, 1, uoflow=False),
+        a = histogram(integer_axis(0, 1, uoflow=False),
                        regular_axis(2, 0, 2, uoflow=False))
         a.fill(numpy.array([[-1., -1.], [0., 1.], [1., 0.1]]))
         self.assertEqual(a[0, 0], 0)
         self.assertEqual(a[0, 1], 1)
         self.assertEqual(a[1, 0], 1)
         self.assertEqual(a[1, 1], 0)
-        a = nhistogram(integer_axis(0, 2, uoflow=False))
+        a = histogram(integer_axis(0, 2, uoflow=False))
         a.fill([0, 0, 1, 2])
         a.fill((1, 0, 2, 2))
         self.assertEqual(a[0], 3)
diff --git a/test/zero_suppression_test.cpp b/test/zero_suppression_test.cpp
index acd4425d..7b415eb6 100644
--- a/test/zero_suppression_test.cpp
+++ b/test/zero_suppression_test.cpp
@@ -5,150 +5,278 @@
 #include <boost/assign/std/vector.hpp>
 #include <iostream>
 using namespace boost::assign;
-using boost::histogram::detail::zero_suppression_encode;
-using boost::histogram::detail::zero_suppression_decode;
+using namespace boost::histogram::detail;
 namespace tt = boost::test_tools;
 
+template <typename T>
 void
-print(const std::vector<char>& v) {
+print(const std::vector<T>& v) {
     std::cerr << "[";
     for (unsigned i = 0; i < v.size(); ++i) {
-        std::cerr << unsigned(v[i]) << (i < v.size() - 1 ? ", " : "]");
+        std::cerr << v[i] << (i < v.size() - 1 ? ", " : "]");
     }
     std::cerr << "\n";
 }
 
-#define EQUAL_VECTORS(a, b) \
-    BOOST_CHECK_EQUAL_COLLECTIONS(a.begin(), a.end(), b.begin(), b.end())
+#define EQUAL_VECTORS(a, b) BOOST_CHECK_EQUAL_COLLECTIONS(a.begin(), a.end(), b.begin(), b.end())
 
 BOOST_AUTO_TEST_CASE( codec_no_zero )
 {
-    std::vector<char> a, b, c(3, 0);
+    std::vector<unsigned> a, b, c(3, 0);
     a += 1, 1, 1;
-    BOOST_CHECK(zero_suppression_encode(b, 3, &a[0], a.size()));
+    BOOST_CHECK(zero_suppression_encode<unsigned>(b, &a[0], a.size()));
     EQUAL_VECTORS(a, b);
-    zero_suppression_decode(&c[0], c.size(), b);
+    zero_suppression_decode<unsigned>(&c[0], c.size(), b);
     EQUAL_VECTORS(a, c);
 }
 
-BOOST_AUTO_TEST_CASE( codec_fail )
-{
-    std::vector<char> a, b;
-    a += 1, 1, 1;
-    BOOST_CHECK(zero_suppression_encode(b, 2, &a[0], a.size()) == false);
-}
-
 BOOST_AUTO_TEST_CASE( codec_empty )
 {
-    std::vector<char> a, b, c;
-    BOOST_CHECK(zero_suppression_encode(b, 3, &a[0], a.size()));
+    std::vector<unsigned> a, b, c;
+    BOOST_CHECK(zero_suppression_encode<unsigned>(b, &a[0], a.size()));
     EQUAL_VECTORS(a, b);
-    zero_suppression_decode(&c[0], c.size(), b);
+    zero_suppression_decode<unsigned>(&c[0], c.size(), b);
     EQUAL_VECTORS(a, c);
 }
 
-BOOST_AUTO_TEST_CASE( codec_zero_0 )
+BOOST_AUTO_TEST_CASE( codec_zero_0a )
 {
-    std::vector<char> a, b, c, d(2, 0);
-    a += 0, 1;
-    c += 0, 1, 1;
-    BOOST_CHECK(zero_suppression_encode(b, c.size(), &a[0], a.size()));
+    std::vector<uint8_t> a, b;
+    a += 0;
+    BOOST_CHECK(zero_suppression_encode<uint8_t>(b, &a[0], a.size()) == false);
+}
+
+BOOST_AUTO_TEST_CASE( codec_zero_1a )
+{
+    std::vector<uint8_t> a, b, c, d(3, 0);
+    a += 1, 0, 0;
+    c += 1, 0, 2;
+    BOOST_CHECK(zero_suppression_encode<uint8_t>(b, &a[0], a.size()));
     EQUAL_VECTORS(b, c);
-    zero_suppression_decode(&d[0], d.size(), b);
+    zero_suppression_decode<uint8_t>(&d[0], d.size(), b);
     EQUAL_VECTORS(a, d);
 }
 
-BOOST_AUTO_TEST_CASE( codec_zero_1 )
+BOOST_AUTO_TEST_CASE( codec_zero_2a )
 {
-    std::vector<char> a, b, c, d(3, 0);
+    std::vector<uint8_t> a, b, c, d(3, 0);
     a += 0, 0, 1;
     c += 0, 2, 1;
-    BOOST_CHECK(zero_suppression_encode(b, c.size(), &a[0], a.size()));
+    BOOST_CHECK(zero_suppression_encode<uint8_t>(b, &a[0], a.size()));
     EQUAL_VECTORS(b, c);
-    zero_suppression_decode(&d[0], d.size(), b);
+    zero_suppression_decode<uint8_t>(&d[0], d.size(), b);
     EQUAL_VECTORS(a, d);
 }
 
-BOOST_AUTO_TEST_CASE( codec_zero_2 )
+BOOST_AUTO_TEST_CASE( codec_zero_3a )
 {
-    std::vector<char> a, b, c, d(2, 0);
+    std::vector<uint8_t> a, b, c, d(2, 0);
     a += 0, 0;
     c += 0, 2;
-    BOOST_CHECK(zero_suppression_encode(b, c.size(), &a[0], a.size()));
+    BOOST_CHECK(zero_suppression_encode<uint8_t>(b, &a[0], a.size()));
     EQUAL_VECTORS(b, c);
-    zero_suppression_decode(&d[0], d.size(), b);
+    zero_suppression_decode<uint8_t>(&d[0], d.size(), b);
     EQUAL_VECTORS(a, d);
 }
 
-BOOST_AUTO_TEST_CASE( codec_zero_3 )
+BOOST_AUTO_TEST_CASE( codec_zero_0b )
 {
-    std::vector<char> a, b, c, d(1, 0);
+    std::vector<unsigned> a, b;
     a += 0;
-    c += 0, 1;
-    BOOST_CHECK(zero_suppression_encode(b, c.size(), &a[0], a.size()));
+    BOOST_CHECK(zero_suppression_encode<unsigned>(b, &a[0], a.size()) == false);
+}
+
+BOOST_AUTO_TEST_CASE( codec_zero_1b )
+{
+    std::vector<unsigned> a, b, c, d(3, 0);
+    a += 1, 0, 0;
+    c += 1, 0, 2;
+    BOOST_CHECK(zero_suppression_encode<unsigned>(b, &a[0], a.size()));
     EQUAL_VECTORS(b, c);
-    zero_suppression_decode(&d[0], d.size(), b);
+    zero_suppression_decode<unsigned>(&d[0], d.size(), b);
+    EQUAL_VECTORS(a, d);
+}
+
+BOOST_AUTO_TEST_CASE( codec_zero_2b )
+{
+    std::vector<unsigned> a, b, c, d(3, 0);
+    a += 0, 0, 1;
+    c += 0, 2, 1;
+    BOOST_CHECK(zero_suppression_encode<unsigned>(b, &a[0], a.size()));
+    EQUAL_VECTORS(b, c);
+    zero_suppression_decode<unsigned>(&d[0], d.size(), b);
+    EQUAL_VECTORS(a, d);
+}
+
+BOOST_AUTO_TEST_CASE( codec_zero_3b )
+{
+    std::vector<unsigned> a, b, c, d(2, 0);
+    a += 0, 0;
+    c += 0, 2;
+    BOOST_CHECK(zero_suppression_encode<unsigned>(b, &a[0], a.size()));
+    EQUAL_VECTORS(b, c);
+    zero_suppression_decode<unsigned>(&d[0], d.size(), b);
+    EQUAL_VECTORS(a, d);
+}
+
+BOOST_AUTO_TEST_CASE( codec_zero_0c )
+{
+    std::vector<uint64_t> a, b;
+    a += 0;
+    BOOST_CHECK(zero_suppression_encode<uint64_t>(b, &a[0], a.size()) == false);
+}
+
+BOOST_AUTO_TEST_CASE( codec_zero_1c )
+{
+    std::vector<uint64_t> a, b, c, d(3, 0);
+    a += 1, 0, 0;
+    c += 1, 0, 2;
+    BOOST_CHECK(zero_suppression_encode<uint64_t>(b, &a[0], a.size()));
+    EQUAL_VECTORS(b, c);
+    zero_suppression_decode<uint64_t>(&d[0], d.size(), b);
+    EQUAL_VECTORS(a, d);
+}
+
+BOOST_AUTO_TEST_CASE( codec_zero_2c )
+{
+    std::vector<uint64_t> a, b, c, d(3, 0);
+    a += 0, 0, 1;
+    c += 0, 2, 1;
+    BOOST_CHECK(zero_suppression_encode<uint64_t>(b, &a[0], a.size()));
+    EQUAL_VECTORS(b, c);
+    zero_suppression_decode<uint64_t>(&d[0], d.size(), b);
+    EQUAL_VECTORS(a, d);
+}
+
+BOOST_AUTO_TEST_CASE( codec_zero_3c )
+{
+    std::vector<uint64_t> a, b, c, d(2, 0);
+    a += 0, 0;
+    c += 0, 2;
+    BOOST_CHECK(zero_suppression_encode<uint64_t>(b, &a[0], a.size()));
+    EQUAL_VECTORS(b, c);
+    zero_suppression_decode<uint64_t>(&d[0], d.size(), b);
+    EQUAL_VECTORS(a, d);
+}
+
+BOOST_AUTO_TEST_CASE( codec_zero_0d )
+{
+    std::vector<wtype> a, b;
+    a += 0;
+    BOOST_CHECK(zero_suppression_encode<wtype>(b, &a[0], a.size()) == false);
+}
+
+BOOST_AUTO_TEST_CASE( codec_zero_1d )
+{
+    std::vector<wtype> a, b, c, d(3, 0);
+    a += 1, 0, 0;
+    c += 1, 0, 2;
+    BOOST_CHECK(zero_suppression_encode<wtype>(b, &a[0], a.size()));
+    EQUAL_VECTORS(b, c);
+    zero_suppression_decode<wtype>(&d[0], d.size(), b);
+    EQUAL_VECTORS(a, d);
+}
+
+BOOST_AUTO_TEST_CASE( codec_zero_2d )
+{
+    std::vector<wtype> a, b, c, d(3, 0);
+    a += 0, 0, 1;
+    c += 0, 2, 1;
+    BOOST_CHECK(zero_suppression_encode<wtype>(b, &a[0], a.size()));
+    EQUAL_VECTORS(b, c);
+    zero_suppression_decode<wtype>(&d[0], d.size(), b);
+    EQUAL_VECTORS(a, d);
+}
+
+BOOST_AUTO_TEST_CASE( codec_zero_3d )
+{
+    std::vector<wtype> a, b, c, d(2, 0);
+    a += 0, 0;
+    c += 0, 2;
+    BOOST_CHECK(zero_suppression_encode<wtype>(b, &a[0], a.size()));
+    EQUAL_VECTORS(b, c);
+    zero_suppression_decode<wtype>(&d[0], d.size(), b);
     EQUAL_VECTORS(a, d);
 }
 
 BOOST_AUTO_TEST_CASE( codec_zero_4 )
 {
-    std::vector<char> a, b, c, d(3, 0);
-    a += 0, 1, 0;
-    c += 0, 1, 1, 0, 1;
-    BOOST_CHECK(zero_suppression_encode(b, c.size(), &a[0], a.size()));
+    std::vector<unsigned> a, b, c, d(5, 0);
+    a += 0, 0, 0, 1, 0;
+    c += 0, 3, 1, 0, 1;
+    BOOST_CHECK(zero_suppression_encode<unsigned>(b, &a[0], a.size()));
     EQUAL_VECTORS(b, c);
-    zero_suppression_decode(&d[0], d.size(), b);
+    zero_suppression_decode<unsigned>(&d[0], d.size(), b);
     EQUAL_VECTORS(a, d);
 }
 
 BOOST_AUTO_TEST_CASE( codec_zero_5 )
 {
-    std::vector<char> a, b, c, d(4, 0);
-    a += 0, 1, 0, 0;
-    c += 0, 1, 1, 0, 2;
-    BOOST_CHECK(zero_suppression_encode(b, c.size(), &a[0], a.size()));
+    std::vector<unsigned> a, b, c, d(5, 0);
+    a += 0, 1, 0, 0, 0;
+    c += 0, 1, 1, 0, 3;
+    BOOST_CHECK(zero_suppression_encode<unsigned>(b, &a[0], a.size()));
     EQUAL_VECTORS(b, c);
-    zero_suppression_decode(&d[0], d.size(), b);
+    zero_suppression_decode<unsigned>(&d[0], d.size(), b);
     EQUAL_VECTORS(a, d);
 }
 
 BOOST_AUTO_TEST_CASE( codec_zero_6 )
 {
-    std::vector<char> a(255, 0), b, c, d(255, 0);
+    std::vector<uint8_t> a(255, 0), b, c, d(255, 0);
     c += 0, 255;
-    BOOST_CHECK(zero_suppression_encode(b, c.size(), &a[0], a.size()));
+    BOOST_CHECK(zero_suppression_encode<uint8_t>(b, &a[0], a.size()));
     EQUAL_VECTORS(b, c);
-    zero_suppression_decode(&d[0], d.size(), b);
+    zero_suppression_decode<uint8_t>(&d[0], d.size(), b);
     EQUAL_VECTORS(a, d);
 }
 
 BOOST_AUTO_TEST_CASE( codec_zero_7 )
 {
-    std::vector<char> a(256, 0), b, c, d(256, 0);
+    std::vector<uint8_t> a(256, 0), b, c, d(256, 0);
     c += 0, 0;
-    BOOST_CHECK(zero_suppression_encode(b, c.size(), &a[0], a.size()));
+    BOOST_CHECK(zero_suppression_encode<uint8_t>(b, &a[0], a.size()));
     EQUAL_VECTORS(b, c);
-    zero_suppression_decode(&d[0], d.size(), b);
+    zero_suppression_decode<uint8_t>(&d[0], d.size(), b);
     EQUAL_VECTORS(a, d);
 }
 
 BOOST_AUTO_TEST_CASE( codec_zero_8 )
 {
-    std::vector<char> a(257, 0), b, c, d(257, 0);
+    std::vector<uint8_t> a(257, 0), b, c, d(257, 0);
     c += 0, 0, 0, 1;
-    BOOST_CHECK(zero_suppression_encode(b, c.size(), &a[0], a.size()));
+    BOOST_CHECK(zero_suppression_encode<uint8_t>(b, &a[0], a.size()));
     EQUAL_VECTORS(b, c);
-    zero_suppression_decode(&d[0], d.size(), b);
+    zero_suppression_decode<uint8_t>(&d[0], d.size(), b);
     EQUAL_VECTORS(a, d);
 }
 
 BOOST_AUTO_TEST_CASE( codec_zero_9 )
 {
-    std::vector<char> a(1000, 0), b, c, d(1000, 0);
+    std::vector<uint8_t> a(1000, 0), b, c, d(1000, 0);
     c += 0, 0, 0, 0, 0, 0, 0, 232;
-    BOOST_CHECK(zero_suppression_encode(b, c.size(), &a[0], a.size()));
+    BOOST_CHECK(zero_suppression_encode<uint8_t>(b, &a[0], a.size()));
     EQUAL_VECTORS(b, c);
-    zero_suppression_decode(&d[0], d.size(), b);
+    zero_suppression_decode<uint8_t>(&d[0], d.size(), b);
+    EQUAL_VECTORS(a, d);
+}
+
+BOOST_AUTO_TEST_CASE( codec_zero_10 )
+{
+    std::vector<uint16_t> a(1000, 0), b, c, d(1000, 0);
+    c += 0, 1000;
+    BOOST_CHECK(zero_suppression_encode<uint16_t>(b, &a[0], a.size()));
+    EQUAL_VECTORS(b, c);
+    zero_suppression_decode<uint16_t>(&d[0], d.size(), b);
+    EQUAL_VECTORS(a, d);
+}
+
+BOOST_AUTO_TEST_CASE( codec_zero_11 )
+{
+    std::vector<uint16_t> a(65536, 0), b, c, d(65536, 0);
+    c += 0, 0;
+    BOOST_CHECK(zero_suppression_encode<uint16_t>(b, &a[0], a.size()));
+    EQUAL_VECTORS(b, c);
+    zero_suppression_decode<uint16_t>(&d[0], d.size(), b);
     EQUAL_VECTORS(a, d);
 }