diff --git a/CMake/CMakeLists.txt b/CMake/CMakeLists.txt
index 8b57007..864b108 100644
--- a/CMake/CMakeLists.txt
+++ b/CMake/CMakeLists.txt
@@ -142,6 +142,8 @@ endif()
 # necessary
 # enable_testing()
 
+if(0)
+
 message(STATUS "test_cast")
 add_executable( test_cast
   ../test/test_cast.cpp
@@ -199,6 +201,20 @@ add_executable( test ../test/test.cpp)
 target_link_libraries( test  ${Boost_LIBRARIES} )
 add_test(NAME test COMMAND test)
 
+endif()
+
+file(GLOB test_files
+  RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}" 
+  "${CMAKE_CURRENT_SOURCE_DIR}/../test/*.cpp"
+)
+foreach(test_file_path ${test_files} )
+    set(test_file_name get_filename_component( NAME ${test_file_path} ) )
+    message(STATUS "${test_file_path"})
+    add_executable( ${test_file_path} ../test/${test_file_path}.cpp)
+    target_link_libraries( ${test_file_path}  ${Boost_LIBRARIES} )
+    add_test(NAME${test_file_path} COMMAND ${test_file_path})
+endforeach(t)
+
 # end test targets
 ####################
 
diff --git a/include/checked.hpp b/include/checked.hpp
new file mode 100644
index 0000000..297fe3e
--- /dev/null
+++ b/include/checked.hpp
@@ -0,0 +1,366 @@
+#ifndef BOOST_NUMERIC_CHECKED_HPP
+#define BOOST_NUMERIC_CHECKED_HPP
+
+// MS compatible compilers support #pragma once
+#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+# pragma once
+#endif
+
+//  Copyright (c) 2012 Robert Ramey
+//
+// Distributed under the Boost Software License, Version 1.0. (See
+// accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+// contains operations for doing checked aritmetic on native
+// C++ types.
+
+#include "overflow.hpp"
+#include "safe_compare.hpp"
+#include "safe_cast.hpp"
+
+// we could have used decltype and auto for C++11 but we've decided
+// to use boost/typeof to be compatible with older compilers
+#include <boost/typeof/typeof.hpp>
+
+namespace boost {
+namespace numeric {
+namespace checked {
+
+    namespace detail {
+    template<bool TS, bool US>
+    struct addition;
+
+    // both arguments unsigned
+    template<>
+    struct addition<false, false> {
+        template<class R, class T, class U>
+        static constexpr bool overflow(const R & r, const T & t, const U & u){
+            return boost::numeric::safe_compare::less_than(r, t)
+            || boost::numeric::safe_compare::less_than(r, u);
+        }
+        template<class T, class U>
+        static constexpr bool addition_overflow(const T & t, const U & u){
+            return overflow(t + u, t, u);
+        }
+        template<class R, class T, class U>
+        static R add(const T & t, const U & u) {
+            R tmp = t + u;
+            if(overflow(tmp, t, u))
+                 boost::numeric::overflow("safe range addition result overflow");
+            return tmp;
+        }
+    };
+    // both arguments signed
+    template<>
+    struct addition<true, true> {
+        template<class R, class T, class U>
+        static constexpr bool overflow(const R & r, const T & t, const U & u){
+            return boost::numeric::safe_compare::less_than(r, t)
+            || boost::numeric::safe_compare::less_than(r, u);
+        }
+        template<class T, class U>
+        static constexpr bool addition_overflow(const T & t, const U & u){
+            return overflow(t + u, t, u);
+        }
+        template<class R, class T, class U>
+        static R add(const T & t, const U & u) {
+            if(t > 0 && u > 0){
+                R tmp = t + u;
+                if(tmp < 0)
+                    boost::numeric::overflow("safe range addition result overflow");
+                return tmp;
+            }
+            if(t < 0 && u < 0){
+                R tmp = t + u;
+                if(tmp >= 0)
+                    boost::numeric::overflow("safe range addition result underflow");
+                return tmp;
+            }
+            return t + u;
+        }
+    };
+    // T unsigned, U signed
+    template<>
+    struct addition<false, true> {
+        template<class R, class T, class U>
+        static R add(const T & t, const U & u){
+            if(boost::numeric::is_unsigned<R>::value){
+                if(u < 0)
+                    overflow("safe range right operand value altered");
+                return addition<false, false>::add<R>(
+                    t,
+                    static_cast<typename boost::make_unsigned<T>::type>(u)
+                );
+            }
+            else{
+                if(u > 0){
+                    R tmp = t + u;
+                    if(tmp <= 0)
+                        overflow("safe range addition result overflow");
+                    return t + u;
+                }
+            }
+            return t + u;
+        }
+    };
+    // T signed, U unsigned
+    template<>
+    struct addition<true, false> {
+        template<class R, class T, class U>
+        static R add(const T & t, const U & u){
+            return addition<false, true>::add<R>(u, t);
+        }
+    };
+    } // detail
+
+    template<class R, class T, class U>
+    R add(const T & t, const U & u){
+        return detail::addition<
+            boost::is_unsigned<T>::value,
+            boost::is_unsigned<U>::value
+        >::template add<R>(
+            t, u
+        );
+    }
+} // checked
+
+namespace detail {
+
+    ////////////////////////////////////////////////////
+    // layer 0 - detect overflows / alteration at the
+    // atomic operation level taking care to work around
+    // otherwise undetect alterations in integers due
+    // to machine architecture.  Note presumption of twos
+    // complement integer arithmetic
+
+    /////////////////////////////
+    // subtraction implementation
+    template<bool TS, bool US>
+    struct check_subtraction_overflow{};
+
+    // both arguments signed
+    template<>
+    struct check_subtraction_overflow<true, true> {
+        template<class T, class U>
+        static BOOST_TYPEOF_TPL(T() + U())
+        subtract(const T & t, const U & u){
+            BOOST_AUTO_TPL(tmp, t - u);
+            if(t > 0 && u < 0){
+                if(tmp < 0)
+                    overflow("safe range subtraction result overflow");
+            }
+            if(t < 0 && u > 0)
+                if(tmp >= 0){
+                    overflow("safe range subtraction result underflow");
+            }
+            return tmp;
+        }
+    };
+    // both arguments unsigned
+    template<>
+    struct check_subtraction_overflow<false, false> {
+        template<class T, class U>
+        static BOOST_TYPEOF_TPL(T() + U())
+        subtract(const T & t, const U & u) {
+            if(safe_compare::less_than(t, u))
+                overflow("safe range subtraction unsigned difference less than zero");
+            return t - u;
+        }
+    };
+    // T unsigned, U signed
+    template<>
+    struct check_subtraction_overflow<false, true> {
+        template<class T, class U>
+        static BOOST_TYPEOF_TPL(T() + U())
+        subtract(const T & t, const U & u){
+            typedef BOOST_TYPEOF_TPL(T() + U()) result_type;
+            if(boost::numeric::is_unsigned<result_type>::value){
+                if(u < 0)
+                    overflow("safe range left operand value altered");
+                // u >= 0
+                if(u > t)
+                    overflow("unsigned result is negative");
+           }
+           // result is signed
+           return t - u;
+        }
+    };
+    // T signed, U unsigned
+    template<>
+    struct check_subtraction_overflow<true, false> {
+        template<class T, class U>
+        static BOOST_TYPEOF_TPL(T() + U())
+        subtract(const T & t, const U & u){
+            typedef BOOST_TYPEOF_TPL(T() + U()) result_type;
+            if(boost::numeric::is_unsigned<result_type>::value){
+                return check_subtraction_overflow<false, false>::subtract(
+                    safe_cast<result_type>(t),
+                    safe_cast<result_type>(u)
+                );
+            }
+            // result is signed
+            return check_subtraction_overflow<true, true>::subtract(
+                t,
+                safe_cast<result_type>(u)
+            );
+        }
+    };
+
+    ////////////////////////////////
+    // multiplication implementation
+
+    template<class T, class U>
+    BOOST_TYPEOF_TPL(T() * U())
+    check_multiplication_overflow(const T & t, const U & u){
+        typedef BOOST_TYPEOF_TPL(T() * U()) result_type;
+        char const * const msg = "safe range multiplication overflow";
+        // presume that size of uintmax_t and intmax_t are the same
+        typedef bits<boost::uintmax_t> available_bits;
+
+        if(multiply_result_bits<T, U>::value
+        <= boost::numeric::bits<result_type>::value)
+            return t * u;
+
+        if(multiply_result_bits<T, U>::value <= available_bits::value){
+            typedef typename multiply_result_type<T, U>::type temp_type;
+            temp_type tmp = static_cast<temp_type>(t) * temp_type(u);
+            // the following works for both positive and negative results
+            // and for both signed and unsigned numbers
+            if(tmp > boost::integer_traits<result_type>::const_max)
+                boost::numeric::overflow(msg);
+            if(tmp < boost::integer_traits<result_type>::const_min)
+                boost::numeric::overflow(msg);
+            return static_cast<result_type>(tmp);
+        }
+
+        // when the there is no native type which can hold the product
+        // use multible precision
+
+        // t is factored as (a << temp_bits) + b
+        // u is factored as (c << temp_bits) + d
+        // so we use multi-precision:
+        // a + b
+        // c + d
+        // -----
+        //    bd
+        //   ad
+        //   cb
+        //  ac
+        // -----
+        //    ..
+
+        if(boost::numeric::is_unsigned<result_type>::value
+        && (t < 0 || u < 0))
+            overflow("conversion of negative value to unsigned");
+
+        if(t == 1)
+            return u;
+        if(u == 1)
+            return t;
+            
+        result_type rt = t;
+        if(rt < 0){
+            rt = ~rt + 1;
+            // address
+            if(rt < 0)
+                overflow("overflow of negative value");
+        }
+        result_type ru = u;
+        if(ru < 0){
+            ru = ~ru + 1;
+            // address
+            if(ru < 0)
+                overflow("overflow of negative value");
+        }
+
+        // check positive values for overflow
+
+        // t is factored as (a << temp_bits) + b
+        // u is factored as (c << temp_bits) + d
+        // so we use multi-precision:
+        // a + b
+        // c + d
+        // -----
+        //    bd
+        //   ad
+        //   cb
+        //  ac
+        // -----
+        //    ..
+
+        typedef boost::uintmax_t accumulator_type;
+        const int temp_bits = bits<accumulator_type>::value / 2;
+        typedef typename boost::uint_t<temp_bits>::least temp_type;
+
+        temp_type a = (static_cast<accumulator_type>(rt) >> temp_bits);
+        temp_type c = (static_cast<accumulator_type>(ru) >> temp_bits);
+        if(0 != a && 0 != c)
+            overflow(msg);
+
+        temp_type b = static_cast<temp_type>(rt);
+        if((static_cast<accumulator_type>(b) * static_cast<accumulator_type>(c) >> temp_bits) > 0)
+            overflow(msg);
+
+        temp_type d = static_cast<const temp_type>(ru);
+        if(0 != (static_cast<accumulator_type>(a) * static_cast<accumulator_type>(d) >> temp_bits))
+            overflow(msg);
+            
+        return t * u;
+    }
+    template<class T, class U>
+    BOOST_TYPEOF_TPL(T() / U())
+    check_division_overflow(const T & t, const U & u){
+        if(0 == u)
+            overflow("divide by zero");
+
+        if(boost::numeric::is_signed<U>::value){
+            // t unsigned, u signed
+            if(boost::numeric::is_unsigned<T>::value){
+                if(u < 0){
+                    overflow("conversion of negative value to unsigned");
+                }
+            }
+            else{
+            // both signed
+                // pathological case: change sign on negative number so it overflows
+                if(t == boost::integer_traits<T>::const_min && u == -1)
+                    overflow("overflow in result");
+            }
+        }
+        // both unsigned
+        // t signed, u unsigned
+        return t / u;
+    }
+    template<class T, class U>
+    BOOST_TYPEOF_TPL(T() / U())
+    check_modulus_overflow(const T & t, const U & u){
+        if(0 == u)
+            overflow("modulus divide by zero");
+
+        if(boost::numeric::is_signed<U>::value){
+            // t unsigned, u signed
+            if(boost::numeric::is_unsigned<T>::value){
+                if(u < 0){
+                    overflow("conversion of negative value to unsigned");
+                }
+            }
+            else{
+            // both signed
+                // pathological case: change sign on negative number so it overflows
+                if(t == boost::integer_traits<T>::const_min && u == -1)
+                    overflow("overflow in result");
+            }
+        }
+        // both unsigned
+        // t signed, u unsigned
+        return t % u;
+    }
+
+}   // detail
+
+
+} // numeric
+} // boost
+
+#endif // BOOST_NUMERIC__HPP
diff --git a/include/native.hpp b/include/native.hpp
index 2a404f5..dffdab2 100644
--- a/include/native.hpp
+++ b/include/native.hpp
@@ -34,7 +34,7 @@ struct native {
         typedef decltype(
             typename boost::numeric::base_type<T>::type()
           + typename boost::numeric::base_type<U>::type()
-        ) type;
+        ) native_result_type;
     };
 };
 
diff --git a/include/safe_range.hpp b/include/safe_range.hpp
index b5559c5..baa649f 100644
--- a/include/safe_range.hpp
+++ b/include/safe_range.hpp
@@ -12,6 +12,8 @@
 // accompanying file LICENSE_1_0.txt or copy at
 // http://www.boost.org/LICENSE_1_0.txt)
 
+#include "checked.hpp"
+
 #include "numeric.hpp"
 #include "safe_compare.hpp"
 #include "safe_cast.hpp"
@@ -53,102 +55,6 @@
 #include <boost/typeof/typeof.hpp>
 
 namespace boost {
-namespace numeric {
-
-namespace checked {
-    template<bool TS, bool US>
-    struct addition;
-
-    // both arguments unsigned
-    template<>
-    struct addition<false, false> {
-        template<class R, class T, class U>
-        static constexpr bool overflow(const R & r, const T & t, const U & u){
-            return boost::numeric::safe_compare::less_than(r, t)
-            || boost::numeric::safe_compare::less_than(r, u);
-        }
-        template<class T, class U>
-        static constexpr bool addition_overflow(const T & t, const U & u){
-            return overflow(t + u, t, u);
-        }
-        template<class R, class T, class U>
-        static R add(const T & t, const U & u) {
-            R tmp = t + u;
-            if(overflow(tmp, t, u))
-                 boost::numeric::overflow("safe range addition result overflow");
-            return tmp;
-        }
-    };
-    // both arguments signed
-    template<>
-    struct addition<true, true> {
-        template<class R, class T, class U>
-        static constexpr bool overflow(const R & r, const T & t, const U & u){
-            return boost::numeric::safe_compare::less_than(r, t)
-            || boost::numeric::safe_compare::less_than(r, u);
-        }
-        template<class T, class U>
-        static constexpr bool addition_overflow(const T & t, const U & u){
-            return overflow(t + u, t, u);
-        }
-        template<class R, class T, class U>
-        static R add(const T & t, const U & u) {
-            if(t > 0 && u > 0){
-                R tmp = t + u;
-                if(tmp < 0)
-                    boost::numeric::overflow("safe range addition result overflow");
-                return tmp;
-            }
-            if(t < 0 && u < 0){
-                R tmp = t + u;
-                if(tmp >= 0)
-                    boost::numeric::overflow("safe range addition result underflow");
-                return tmp;
-            }
-            return t + u;
-        }
-    };
-    // T unsigned, U signed
-    template<>
-    struct addition<false, true> {
-        template<class R, class T, class U>
-        static R add(const T & t, const U & u){
-            if(boost::numeric::is_unsigned<R>::value){
-                if(u < 0)
-                    overflow("safe range right operand value altered");
-                return addition<false, false>::add<R>(
-                    t,
-                    static_cast<typename boost::make_unsigned<T>::type>(u)
-                );
-            }
-            else{
-                if(u > 0){
-                    R tmp = t + u;
-                    if(tmp <= 0)
-                        overflow("safe range addition result overflow");
-                    return t + u;
-                }
-            }
-            return t + u;
-        }
-    };
-    // T signed, U unsigned
-    template<>
-    struct addition<true, false> {
-        template<class R, class T, class U>
-        static R add(const T & t, const U & u){
-            return addition<false, true>::add<R>(u, t);
-        }
-    };
-
-    template<class R, class T, class U>
-    R add(const T & t, const U & u){
-        return addition<boost::is_unsigned<T>::value, boost::is_unsigned<U>::value>
-        ::template add<R>(
-            t, u
-        );
-    }
-}
 namespace detail {
 
     ////////////////////////////////////////////////////
@@ -172,11 +78,11 @@ namespace detail {
             BOOST_AUTO_TPL(tmp, t - u);
             if(t > 0 && u < 0){
                 if(tmp < 0)
-                    overflow("safe range subtraction result overflow");
+                    boost::numeric::overflow("safe range subtraction result overflow");
             }
             if(t < 0 && u > 0)
                 if(tmp >= 0){
-                    overflow("safe range subtraction result underflow");
+                    boost::numeric::overflow("safe range subtraction result underflow");
             }
             return tmp;
         }
@@ -187,8 +93,8 @@ namespace detail {
         template<class T, class U>
         static BOOST_TYPEOF_TPL(T() + U())
         subtract(const T & t, const U & u) {
-            if(safe_compare::less_than(t, u))
-                overflow("safe range subtraction unsigned difference less than zero");
+            if(boost::numeric::safe_compare::less_than(t, u))
+                boost::numeric::overflow("safe range subtraction unsigned difference less than zero");
             return t - u;
         }
     };
@@ -201,10 +107,10 @@ namespace detail {
             typedef BOOST_TYPEOF_TPL(T() + U()) result_type;
             if(boost::numeric::is_unsigned<result_type>::value){
                 if(u < 0)
-                    overflow("safe range left operand value altered");
+                    boost::numeric::overflow("safe range left operand value altered");
                 // u >= 0
                 if(u > t)
-                    overflow("unsigned result is negative");
+                    boost::numeric::overflow("unsigned result is negative");
            }
            // result is signed
            return t - u;
@@ -219,14 +125,14 @@ namespace detail {
             typedef BOOST_TYPEOF_TPL(T() + U()) result_type;
             if(boost::numeric::is_unsigned<result_type>::value){
                 return check_subtraction_overflow<false, false>::subtract(
-                    safe_cast<result_type>(t),
-                    safe_cast<result_type>(u)
+                    boost::numeric::safe_cast<result_type>(t),
+                    boost::numeric::safe_cast<result_type>(u)
                 );
             }
             // result is signed
             return check_subtraction_overflow<true, true>::subtract(
                 t,
-                safe_cast<result_type>(u)
+                boost::numeric::safe_cast<result_type>(u)
             );
         }
     };
@@ -240,14 +146,14 @@ namespace detail {
         typedef BOOST_TYPEOF_TPL(T() * U()) result_type;
         char const * const msg = "safe range multiplication overflow";
         // presume that size of uintmax_t and intmax_t are the same
-        typedef bits<boost::uintmax_t> available_bits;
+        typedef boost::numeric::bits<boost::uintmax_t> available_bits;
 
-        if(multiply_result_bits<T, U>::value
+        if(boost::numeric::multiply_result_bits<T, U>::value
         <= boost::numeric::bits<result_type>::value)
             return t * u;
 
-        if(multiply_result_bits<T, U>::value <= available_bits::value){
-            typedef typename multiply_result_type<T, U>::type temp_type;
+        if(boost::numeric::multiply_result_bits<T, U>::value <= boost::numeric::available_bits::value){
+            typedef typename boost::numeric::multiply_result_type<T, U>::type temp_type;
             temp_type tmp = static_cast<temp_type>(t) * temp_type(u);
             // the following works for both positive and negative results
             // and for both signed and unsigned numbers
@@ -276,7 +182,7 @@ namespace detail {
 
         if(boost::numeric::is_unsigned<result_type>::value
         && (t < 0 || u < 0))
-            overflow("conversion of negative value to unsigned");
+            boost::numeric::overflow("conversion of negative value to unsigned");
 
         if(t == 1)
             return u;
@@ -288,14 +194,14 @@ namespace detail {
             rt = ~rt + 1;
             // address
             if(rt < 0)
-                overflow("overflow of negative value");
+                boost::numeric::overflow("overflow of negative value");
         }
         result_type ru = u;
         if(ru < 0){
             ru = ~ru + 1;
             // address
             if(ru < 0)
-                overflow("overflow of negative value");
+                boost::numeric::overflow("overflow of negative value");
         }
 
         // check positive values for overflow
@@ -314,21 +220,21 @@ namespace detail {
         //    ..
 
         typedef boost::uintmax_t accumulator_type;
-        const int temp_bits = bits<accumulator_type>::value / 2;
+        const int temp_bits = boost::numeric::bits<accumulator_type>::value / 2;
         typedef typename boost::uint_t<temp_bits>::least temp_type;
 
         temp_type a = (static_cast<accumulator_type>(rt) >> temp_bits);
         temp_type c = (static_cast<accumulator_type>(ru) >> temp_bits);
         if(0 != a && 0 != c)
-            overflow(msg);
+            boost::numeric::overflow(msg);
 
         temp_type b = static_cast<temp_type>(rt);
         if((static_cast<accumulator_type>(b) * static_cast<accumulator_type>(c) >> temp_bits) > 0)
-            overflow(msg);
+            boost::numeric::overflow(msg);
 
         temp_type d = static_cast<const temp_type>(ru);
         if(0 != (static_cast<accumulator_type>(a) * static_cast<accumulator_type>(d) >> temp_bits))
-            overflow(msg);
+            boost::numeric::overflow(msg);
             
         return t * u;
     }
@@ -336,20 +242,20 @@ namespace detail {
     BOOST_TYPEOF_TPL(T() / U())
     check_division_overflow(const T & t, const U & u){
         if(0 == u)
-            overflow("divide by zero");
+            boost::numeric::overflow("divide by zero");
 
         if(boost::numeric::is_signed<U>::value){
             // t unsigned, u signed
             if(boost::numeric::is_unsigned<T>::value){
                 if(u < 0){
-                    overflow("conversion of negative value to unsigned");
+                    boost::numeric::overflow("conversion of negative value to unsigned");
                 }
             }
             else{
             // both signed
                 // pathological case: change sign on negative number so it overflows
                 if(t == boost::integer_traits<T>::const_min && u == -1)
-                    overflow("overflow in result");
+                    boost::numeric::overflow("overflow in result");
             }
         }
         // both unsigned
@@ -360,20 +266,20 @@ namespace detail {
     BOOST_TYPEOF_TPL(T() / U())
     check_modulus_overflow(const T & t, const U & u){
         if(0 == u)
-            overflow("modulus divide by zero");
+            boost::numeric::overflow("modulus divide by zero");
 
         if(boost::numeric::is_signed<U>::value){
             // t unsigned, u signed
             if(boost::numeric::is_unsigned<T>::value){
                 if(u < 0){
-                    overflow("conversion of negative value to unsigned");
+                    boost::numeric::overflow("conversion of negative value to unsigned");
                 }
             }
             else{
             // both signed
                 // pathological case: change sign on negative number so it overflows
                 if(t == boost::integer_traits<T>::const_min && u == -1)
-                    overflow("overflow in result");
+                    boost::numeric::overflow("overflow in result");
             }
         }
         // both unsigned
@@ -517,27 +423,27 @@ public:
     // comparison operators
     template<class U>
     bool operator<(const U & rhs) const {
-        return safe_compare::less_than(m_t, rhs);
+        return boost::numeric::safe_compare::less_than(m_t, rhs);
     }
     template<class U>
     bool operator>(const U & rhs) const {
-        return safe_compare::greater_than(m_t, rhs);
+        return boost::numeric::safe_compare::greater_than(m_t, rhs);
     }
     template<class U>
     bool operator==(const U & rhs) const {
-        return safe_compare::equal(m_t, rhs);
+        return boost::numeric::safe_compare::equal(m_t, rhs);
     }
     template<class U>
     bool inline operator!=(const U & rhs) const {
-        return ! safe_compare::equal(m_t,rhs);
+        return ! boost::numeric::safe_compare::equal(m_t,rhs);
     }
     template<class U>
     bool inline operator>=(const U & rhs) const {
-        return ! safe_compare::less_than(m_t, rhs);
+        return ! boost::numeric::safe_compare::less_than(m_t, rhs);
     }
     template<class U>
     bool inline operator<=(const U & rhs) const {
-        return ! safe_compare::greater_than(m_t, rhs);
+        return ! boost::numeric::safe_compare::greater_than(m_t, rhs);
     }
 
     /////////////////////////////////////////////////////////////////
@@ -577,7 +483,7 @@ public:
         return detail::check_subtraction_overflow<
             boost::numeric::is_signed<Stored>::value,
             boost::numeric::is_signed<U>::value
-        >::subtract(m_t, safe_cast<BOOST_TYPEOF_TPL(Stored() - U())>(rhs));
+        >::subtract(m_t, boost::numeric::safe_cast<BOOST_TYPEOF_TPL(Stored() - U())>(rhs));
     }
     /////////////////////////////////////////////////////////////////
     // multiplication
@@ -646,10 +552,10 @@ public:
             "right hand side is not an integer type"
         );
         if(m_t < 0)
-            overflow("right shift of negative number undefined");
+            boost::numeric::overflow("right shift of negative number undefined");
         typedef BOOST_TYPEOF_TPL(Stored() >> U()) result_type;
         if(rhs > boost::numeric::bits<Stored>::value)
-            overflow("conversion of negative value to unsigned");
+            boost::numeric::overflow("conversion of negative value to unsigned");
 
         return m_t >> rhs;
     }
@@ -661,10 +567,10 @@ public:
             "right hand side is not an integer type"
         );
         if(m_t < 0)
-            overflow("right shift of negative number undefined");
+            boost::numeric::overflow("right shift of negative number undefined");
         typedef BOOST_TYPEOF_TPL(Stored() >> U()) result_type;
         if(rhs > boost::numeric::bits<Stored>::value)
-            overflow("conversion of negative value to unsigned");
+            boost::numeric::overflow("conversion of negative value to unsigned");
         return m_t << rhs;
     }
 
@@ -679,7 +585,7 @@ public:
         // ...
         // --x;
         if(boost::integer_traits<Stored>::const_max == m_t)
-            overflow("safe range unary negation overflow");
+            boost::numeric::overflow("safe range unary negation overflow");
         return -m_t;
     }
 
@@ -712,7 +618,7 @@ struct get_policy {
 
     typedef typename boost::mpl::if_<
         is_safe<T>,
-        typename boost::numeric::get_policy_t<T>,
+        typename get_policy_t<T>,
         boost::mpl::identity<boost::mpl::void_>
     >::type::type policy_t;
 
@@ -720,7 +626,7 @@ struct get_policy {
 
     typedef typename boost::mpl::if_<
         is_safe<U>,
-        typename boost::numeric::get_policy_t<U>,
+        typename get_policy_t<U>,
         boost::mpl::identity<boost::mpl::void_>
     >::type::type policy_u;