diff DEPENDENCIES/generic/include/boost/multiprecision/cpp_int.hpp @ 16:2665513ce2d3

Add boost headers
author Chris Cannam
date Tue, 05 Aug 2014 11:11:38 +0100
parents
children c530137014c0
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DEPENDENCIES/generic/include/boost/multiprecision/cpp_int.hpp	Tue Aug 05 11:11:38 2014 +0100
@@ -0,0 +1,1808 @@
+///////////////////////////////////////////////////////////////
+//  Copyright 2012 John Maddock. 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_
+
+#ifndef BOOST_MP_CPP_INT_HPP
+#define BOOST_MP_CPP_INT_HPP
+
+#include <iostream>
+#include <iomanip>
+#include <boost/cstdint.hpp>
+#include <boost/multiprecision/number.hpp>
+#include <boost/multiprecision/detail/integer_ops.hpp>
+#include <boost/array.hpp>
+#include <boost/type_traits/is_integral.hpp>
+#include <boost/type_traits/is_floating_point.hpp>
+#include <boost/multiprecision/cpp_int/cpp_int_config.hpp>
+#include <boost/multiprecision/rational_adaptor.hpp>
+#include <boost/detail/endian.hpp>
+#include <boost/integer/static_min_max.hpp>
+#include <boost/type_traits/common_type.hpp>
+#include <boost/type_traits/make_signed.hpp>
+#include <boost/multiprecision/cpp_int/checked.hpp>
+#ifdef BOOST_MP_USER_DEFINED_LITERALS
+#include <boost/multiprecision/cpp_int/value_pack.hpp>
+#endif
+
+namespace boost{
+namespace multiprecision{
+namespace backends{
+
+  using boost::enable_if;
+
+
+#ifdef BOOST_MSVC
+// warning C4127: conditional expression is constant
+#pragma warning(push)
+#pragma warning(disable:4127 4351 4293 4996 4307 4702)
+#endif
+
+template <unsigned MinBits = 0, unsigned MaxBits = 0, cpp_integer_type SignType = signed_magnitude, cpp_int_check_type Checked = unchecked, class Allocator = typename mpl::if_c<MinBits && (MinBits == MaxBits), void, std::allocator<limb_type> >::type >
+struct cpp_int_backend;
+
+template <unsigned MinBits, unsigned MaxBits, cpp_integer_type SignType, cpp_int_check_type Checked, class Allocator, bool trivial = false>
+struct cpp_int_base;
+//
+// Traits class determines the maximum and minimum precision values:
+//
+template <class T> struct max_precision;
+
+template <unsigned MinBits, unsigned MaxBits, cpp_integer_type SignType, cpp_int_check_type Checked, class Allocator>
+struct max_precision<cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator> >
+{
+   static const unsigned value = is_void<Allocator>::value ?
+      static_unsigned_max<MinBits, MaxBits>::value
+      : (((MaxBits >= MinBits) && MaxBits) ? MaxBits : UINT_MAX);
+};
+
+template <class T> struct min_precision;
+
+template <unsigned MinBits, unsigned MaxBits, cpp_integer_type SignType, cpp_int_check_type Checked, class Allocator>
+struct min_precision<cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator> >
+{
+   static const unsigned value = (is_void<Allocator>::value ? static_unsigned_max<MinBits, MaxBits>::value : MinBits);
+};
+//
+// Traits class determines whether the number of bits precision requested could fit in a native type,
+// we call this a "trivial" cpp_int:
+//
+template <class T>
+struct is_trivial_cpp_int
+{
+   static const bool value = false;
+};
+
+template <unsigned MinBits, unsigned MaxBits, cpp_integer_type SignType, cpp_int_check_type Checked, class Allocator>
+struct is_trivial_cpp_int<cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator> >
+{
+   typedef cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator> self;
+   static const bool value = is_void<Allocator>::value && (max_precision<self>::value <= (sizeof(double_limb_type) * CHAR_BIT) - (SignType == signed_packed ? 1 : 0));
+};
+
+template <unsigned MinBits, unsigned MaxBits, cpp_integer_type SignType, cpp_int_check_type Checked, class Allocator>
+struct is_trivial_cpp_int<cpp_int_base<MinBits, MaxBits, SignType, Checked, Allocator, true> >
+{
+   static const bool value = true;
+};
+
+} // namespace backends
+//
+// Traits class to determine whether a cpp_int_backend is signed or not:
+//
+template <unsigned MinBits, unsigned MaxBits, cpp_integer_type SignType, cpp_int_check_type Checked, class Allocator>
+struct is_unsigned_number<backends::cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator> >
+   : public mpl::bool_<(SignType == unsigned_magnitude) || (SignType == unsigned_packed)>{};
+
+namespace backends{
+//
+// Traits class determines whether T should be implicitly convertible to U, or
+// whether the constructor should be made explicit.  The latter happens if we
+// are losing the sign, or have fewer digits precision in the target type:
+//
+template <class T, class U>
+struct is_implicit_cpp_int_conversion;
+
+template <unsigned MinBits, unsigned MaxBits, cpp_integer_type SignType, cpp_int_check_type Checked, class Allocator, unsigned MinBits2, unsigned MaxBits2, cpp_integer_type SignType2, cpp_int_check_type Checked2, class Allocator2>
+struct is_implicit_cpp_int_conversion<cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator>, cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2> >
+{
+   typedef cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator> t1;
+   typedef cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2> t2;
+   static const bool value =
+      (is_signed_number<t2>::value || !is_signed_number<t1>::value)
+      && (max_precision<t1>::value <= max_precision<t2>::value);
+};
+
+//
+// Traits class to determine whether operations on a cpp_int may throw:
+//
+template <class T>
+struct is_non_throwing_cpp_int : public mpl::false_{};
+template <unsigned MinBits, unsigned MaxBits, cpp_integer_type SignType>
+struct is_non_throwing_cpp_int<cpp_int_backend<MinBits, MaxBits, SignType, unchecked, void> > : public mpl::true_ {};
+
+//
+// Traits class, determines whether the cpp_int is fixed precision or not:
+//
+template <class T>
+struct is_fixed_precision;
+template <unsigned MinBits, unsigned MaxBits, cpp_integer_type SignType, cpp_int_check_type Checked, class Allocator>
+struct is_fixed_precision<cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator> >
+   : public mpl::bool_<max_precision<cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator> >::value != UINT_MAX> {};
+
+namespace detail{
+
+inline void verify_new_size(unsigned new_size, unsigned min_size, const mpl::int_<checked>&)
+{
+   if(new_size < min_size)
+      BOOST_THROW_EXCEPTION(std::overflow_error("Unable to allocate sufficient storage for the value of the result: value overflows the maximum allowable magnitude."));
+}
+inline void verify_new_size(unsigned /*new_size*/, unsigned /*min_size*/, const mpl::int_<unchecked>&){}
+
+template <class U>
+inline void verify_limb_mask(bool b, U limb, U mask, const mpl::int_<checked>&)
+{
+   // When we mask out "limb" with "mask", do we loose bits?  If so it's an overflow error:
+   if(b && (limb & ~mask))
+      BOOST_THROW_EXCEPTION(std::overflow_error("Overflow in cpp_int arithmetic: there is insufficient precision in the target type to hold all of the bits of the result."));
+}
+template <class U>
+inline void verify_limb_mask(bool /*b*/, U /*limb*/, U /*mask*/, const mpl::int_<unchecked>&){}
+
+}
+
+//
+// Now define the various data layouts that are possible as partial specializations of the base class,
+// starting with the default arbitrary precision signed integer type:
+//
+template <unsigned MinBits, unsigned MaxBits, cpp_int_check_type Checked, class Allocator>
+struct cpp_int_base<MinBits, MaxBits, signed_magnitude, Checked, Allocator, false> : private Allocator::template rebind<limb_type>::other
+{
+   typedef typename Allocator::template rebind<limb_type>::other allocator_type;
+   typedef typename allocator_type::pointer                      limb_pointer;
+   typedef typename allocator_type::const_pointer                const_limb_pointer;
+   typedef mpl::int_<Checked>                                    checked_type;
+
+   //
+   // Interface invariants:
+   //
+   BOOST_STATIC_ASSERT(!is_void<Allocator>::value);
+
+private:
+   struct limb_data
+   {
+      unsigned capacity;
+      limb_pointer data;
+   };
+
+public:
+   BOOST_STATIC_CONSTANT(unsigned, limb_bits = sizeof(limb_type) * CHAR_BIT);
+   BOOST_STATIC_CONSTANT(limb_type, max_limb_value = ~static_cast<limb_type>(0u));
+   BOOST_STATIC_CONSTANT(limb_type, sign_bit_mask = 1u << (limb_bits - 1));
+   BOOST_STATIC_CONSTANT(unsigned, internal_limb_count =
+      MinBits
+         ? MinBits / limb_bits + (MinBits % limb_bits ? 1 : 0)
+         : sizeof(limb_data) / sizeof(limb_type));
+   BOOST_STATIC_CONSTANT(bool, variable = true);
+
+private:
+   union data_type
+   {
+      limb_data ld;
+      limb_type la[internal_limb_count];
+      limb_type first;
+      double_limb_type double_first;
+
+      BOOST_CONSTEXPR data_type() : first(0) {}
+      BOOST_CONSTEXPR data_type(limb_type i) : first(i) {}
+      BOOST_CONSTEXPR data_type(signed_limb_type i) : first(i < 0 ? -i : i) {}
+#ifdef BOOST_LITTLE_ENDIAN
+      BOOST_CONSTEXPR data_type(double_limb_type i) : double_first(i) {}
+      BOOST_CONSTEXPR data_type(signed_double_limb_type i) : double_first(i < 0 ? -i : i) {}
+#endif
+   };
+
+   data_type   m_data;
+   unsigned    m_limbs;
+   bool        m_sign, m_internal;
+
+public:
+   //
+   // Direct construction:
+   //
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base(limb_type i)BOOST_NOEXCEPT
+      : m_data(i), m_limbs(1), m_sign(false), m_internal(true) { }
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base(signed_limb_type i)BOOST_NOEXCEPT
+      : m_data(i), m_limbs(1), m_sign(i < 0), m_internal(true) { }
+#if defined(BOOST_LITTLE_ENDIAN)
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base(double_limb_type i)BOOST_NOEXCEPT
+      : m_data(i), m_limbs(i > max_limb_value ? 2 : 1), m_sign(false), m_internal(true) { }
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base(signed_double_limb_type i)BOOST_NOEXCEPT
+      : m_data(i), m_limbs(i < 0 ? (static_cast<double_limb_type>(-i) > static_cast<double_limb_type>(max_limb_value) ? 2 : 1) : (i > max_limb_value ? 2 : 1)),
+        m_sign(i < 0), m_internal(true) { }
+#endif
+   //
+   // Helper functions for getting at our internal data, and manipulating storage:
+   //
+   BOOST_MP_FORCEINLINE allocator_type& allocator() BOOST_NOEXCEPT { return *this; }
+   BOOST_MP_FORCEINLINE const allocator_type& allocator()const BOOST_NOEXCEPT { return *this; }
+   BOOST_MP_FORCEINLINE unsigned size()const  BOOST_NOEXCEPT { return m_limbs; }
+   BOOST_MP_FORCEINLINE limb_pointer limbs()  BOOST_NOEXCEPT { return m_internal ? m_data.la : m_data.ld.data; }
+   BOOST_MP_FORCEINLINE const_limb_pointer limbs()const  BOOST_NOEXCEPT { return m_internal ? m_data.la : m_data.ld.data; }
+   BOOST_MP_FORCEINLINE unsigned capacity()const  BOOST_NOEXCEPT { return m_internal ? internal_limb_count : m_data.ld.capacity; }
+   BOOST_MP_FORCEINLINE bool sign()const  BOOST_NOEXCEPT { return m_sign; }
+   void sign(bool b)  BOOST_NOEXCEPT
+   {
+      m_sign = b;
+      // Check for zero value:
+      if(m_sign && (m_limbs == 1))
+      {
+         if(limbs()[0] == 0)
+            m_sign = false;
+      }
+   }
+   void resize(unsigned new_size, unsigned min_size)
+   {
+      static const unsigned max_limbs = MaxBits / (CHAR_BIT * sizeof(limb_type)) + (MaxBits % (CHAR_BIT * sizeof(limb_type)) ? 1 : 0);
+      // We never resize beyond MaxSize:
+      if(new_size > max_limbs)
+         new_size = max_limbs;
+      detail::verify_new_size(new_size, min_size, checked_type());
+      // See if we have enough capacity already:
+      unsigned cap = capacity();
+      if(new_size > cap)
+      {
+         // Allocate a new buffer and copy everything over:
+         cap = (std::min)((std::max)(cap * 4, new_size), max_limbs);
+         limb_pointer pl = allocator().allocate(cap);
+#if BOOST_WORKAROUND(BOOST_MSVC, >= 1600)
+         std::copy(limbs(), limbs() + size(), stdext::checked_array_iterator<limb_pointer>(pl, cap));
+#else
+         std::copy(limbs(), limbs() + size(), pl);
+#endif
+         if(!m_internal)
+            allocator().deallocate(limbs(), capacity());
+         else
+            m_internal = false;
+         m_limbs = new_size;
+         m_data.ld.capacity = cap;
+         m_data.ld.data = pl;
+      }
+      else
+      {
+         m_limbs = new_size;
+      }
+   }
+   BOOST_MP_FORCEINLINE void normalize() BOOST_NOEXCEPT
+   {
+      limb_pointer p = limbs();
+      while((m_limbs-1) && !p[m_limbs - 1])--m_limbs;
+   }
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base() BOOST_NOEXCEPT : m_data(), m_limbs(1), m_sign(false), m_internal(true) {}
+   BOOST_MP_FORCEINLINE cpp_int_base(const cpp_int_base& o) : allocator_type(o), m_limbs(0), m_internal(true)
+   {
+      resize(o.size(), o.size());
+#if BOOST_WORKAROUND(BOOST_MSVC, >= 1600)
+      std::copy(o.limbs(), o.limbs() + o.size(), stdext::checked_array_iterator<limb_pointer>(limbs(), size()));
+#else
+      std::copy(o.limbs(), o.limbs() + o.size(), limbs());
+#endif
+      m_sign = o.m_sign;
+   }
+#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
+   cpp_int_base(cpp_int_base&& o)
+      : allocator_type(static_cast<Allocator&&>(o)), m_limbs(o.m_limbs), m_sign(o.m_sign), m_internal(o.m_internal)
+   {
+      if(m_internal)
+      {
+#if BOOST_WORKAROUND(BOOST_MSVC, >= 1600)
+         std::copy(o.limbs(), o.limbs() + o.size(), stdext::checked_array_iterator<limb_pointer>(limbs(), size()));
+#else
+         std::copy(o.limbs(), o.limbs() + o.size(), limbs());
+#endif
+      }
+      else
+      {
+         m_data.ld = o.m_data.ld;
+         o.m_limbs = 0;
+         o.m_internal = true;
+      }
+   }
+   cpp_int_base& operator = (cpp_int_base&& o) BOOST_NOEXCEPT
+   {
+      if(!m_internal)
+         allocator().deallocate(m_data.ld.data, m_data.ld.capacity);
+      *static_cast<Allocator*>(this) = static_cast<Allocator&&>(o);
+      m_limbs = o.m_limbs;
+      m_sign = o.m_sign;
+      m_internal = o.m_internal;
+      if(m_internal)
+      {
+#if BOOST_WORKAROUND(BOOST_MSVC, >= 1600)
+         std::copy(o.limbs(), o.limbs() + o.size(), stdext::checked_array_iterator<limb_pointer>(limbs(), size()));
+#else
+         std::copy(o.limbs(), o.limbs() + o.size(), limbs());
+#endif
+      }
+      else
+      {
+         m_data.ld = o.m_data.ld;
+         o.m_limbs = 0;
+         o.m_internal = true;
+      }
+      return *this;
+   }
+#endif
+   BOOST_MP_FORCEINLINE ~cpp_int_base() BOOST_NOEXCEPT
+   {
+      if(!m_internal)
+         allocator().deallocate(limbs(), capacity());
+   }
+   void assign(const cpp_int_base& o)
+   {
+      if(this != &o)
+      {
+         static_cast<allocator_type&>(*this) = static_cast<const allocator_type&>(o);
+         m_limbs = 0;
+         resize(o.size(), o.size());
+#if BOOST_WORKAROUND(BOOST_MSVC, >= 1600)
+         std::copy(o.limbs(), o.limbs() + o.size(), stdext::checked_array_iterator<limb_pointer>(limbs(), size()));
+#else
+         std::copy(o.limbs(), o.limbs() + o.size(), limbs());
+#endif
+         m_sign = o.m_sign;
+      }
+   }
+   BOOST_MP_FORCEINLINE void negate() BOOST_NOEXCEPT
+   {
+      m_sign = !m_sign;
+      // Check for zero value:
+      if(m_sign && (m_limbs == 1))
+      {
+         if(limbs()[0] == 0)
+            m_sign = false;
+      }
+   }
+   BOOST_MP_FORCEINLINE bool isneg()const BOOST_NOEXCEPT
+   {
+      return m_sign;
+   }
+   BOOST_MP_FORCEINLINE void do_swap(cpp_int_base& o) BOOST_NOEXCEPT
+   {
+      std::swap(m_data, o.m_data);
+      std::swap(m_sign, o.m_sign);
+      std::swap(m_internal, o.m_internal);
+      std::swap(m_limbs, o.m_limbs);
+   }
+};
+
+#ifndef BOOST_NO_INCLASS_MEMBER_INITIALIZATION
+
+template <unsigned MinBits, unsigned MaxBits, cpp_int_check_type Checked, class Allocator>
+const unsigned cpp_int_base<MinBits, MaxBits, signed_magnitude, Checked, Allocator, false>::limb_bits;
+template <unsigned MinBits, unsigned MaxBits, cpp_int_check_type Checked, class Allocator>
+const limb_type cpp_int_base<MinBits, MaxBits, signed_magnitude, Checked, Allocator, false>::max_limb_value;
+template <unsigned MinBits, unsigned MaxBits, cpp_int_check_type Checked, class Allocator>
+const limb_type cpp_int_base<MinBits, MaxBits, signed_magnitude, Checked, Allocator, false>::sign_bit_mask;
+template <unsigned MinBits, unsigned MaxBits, cpp_int_check_type Checked, class Allocator>
+const unsigned cpp_int_base<MinBits, MaxBits, signed_magnitude, Checked, Allocator, false>::internal_limb_count;
+template <unsigned MinBits, unsigned MaxBits, cpp_int_check_type Checked, class Allocator>
+const bool cpp_int_base<MinBits, MaxBits, signed_magnitude, Checked, Allocator, false>::variable;
+
+#endif
+
+template <unsigned MinBits, unsigned MaxBits, cpp_int_check_type Checked, class Allocator>
+struct cpp_int_base<MinBits, MaxBits, unsigned_magnitude, Checked, Allocator, false> : private Allocator::template rebind<limb_type>::other
+{
+   //
+   // There is currently no support for unsigned arbitrary precision arithmetic, largely
+   // because it's not clear what subtraction should do:
+   //
+   BOOST_STATIC_ASSERT_MSG(((sizeof(Allocator) == 0) && !is_void<Allocator>::value), "There is curently no support for unsigned arbitrary precision integers.");
+};
+//
+// Fixed precision (i.e. no allocator), signed-magnitude type with limb-usage count:
+//
+template <unsigned MinBits, cpp_int_check_type Checked>
+struct cpp_int_base<MinBits, MinBits, signed_magnitude, Checked, void, false>
+{
+   typedef limb_type*                      limb_pointer;
+   typedef const limb_type*                const_limb_pointer;
+   typedef mpl::int_<Checked>              checked_type;
+
+   //
+   // Interface invariants:
+   //
+   BOOST_STATIC_ASSERT_MSG(MinBits > sizeof(double_limb_type) * CHAR_BIT, "Template parameter MinBits is inconsistent with the parameter trivial - did you mistakingly try to override the trivial parameter?");
+
+public:
+   BOOST_STATIC_CONSTANT(unsigned, limb_bits = sizeof(limb_type) * CHAR_BIT);
+   BOOST_STATIC_CONSTANT(limb_type, max_limb_value = ~static_cast<limb_type>(0u));
+   BOOST_STATIC_CONSTANT(limb_type, sign_bit_mask = 1u << (limb_bits - 1));
+   BOOST_STATIC_CONSTANT(unsigned, internal_limb_count = MinBits / limb_bits + (MinBits % limb_bits ? 1 : 0));
+   BOOST_STATIC_CONSTANT(bool, variable = false);
+   BOOST_STATIC_CONSTANT(limb_type, upper_limb_mask = MinBits % limb_bits ? (limb_type(1) << (MinBits % limb_bits)) -1 : (~limb_type(0)));
+   BOOST_STATIC_ASSERT_MSG(internal_limb_count >= 2, "A fixed precision integer type must have at least 2 limbs");
+
+private:
+   union data_type{
+      limb_type          m_data[internal_limb_count];
+      limb_type          m_first_limb;
+      double_limb_type   m_double_first_limb;
+
+      BOOST_CONSTEXPR data_type() : m_first_limb(0) {}
+      BOOST_CONSTEXPR data_type(limb_type i) : m_first_limb(i) {}
+      BOOST_CONSTEXPR data_type(double_limb_type i) : m_double_first_limb(i) {}
+#if defined(BOOST_MP_USER_DEFINED_LITERALS)
+      template <limb_type...VALUES>
+      BOOST_CONSTEXPR data_type(literals::detail::value_pack<VALUES...>) : m_data{ VALUES... } {}
+#endif
+   } m_wrapper;
+   boost::uint16_t    m_limbs;
+   bool               m_sign;
+
+public:
+   //
+   // Direct construction:
+   //
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base(limb_type i)BOOST_NOEXCEPT
+      : m_wrapper(i), m_limbs(1), m_sign(false) {}
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base(signed_limb_type i)BOOST_NOEXCEPT
+      : m_wrapper(limb_type(i < 0 ? -i : i)), m_limbs(1), m_sign(i < 0) {}
+#if defined(BOOST_LITTLE_ENDIAN)
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base(double_limb_type i)BOOST_NOEXCEPT
+      : m_wrapper(i), m_limbs(i > max_limb_value ? 2 : 1), m_sign(false) {}
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base(signed_double_limb_type i)BOOST_NOEXCEPT
+      : m_wrapper(double_limb_type(i < 0 ? -i : i)),
+        m_limbs(i < 0 ? (static_cast<double_limb_type>(-i) > max_limb_value ? 2 : 1) : (i > max_limb_value ? 2 : 1)),
+        m_sign(i < 0) {}
+#endif
+#if defined(BOOST_MP_USER_DEFINED_LITERALS)
+      template <limb_type...VALUES>
+      BOOST_CONSTEXPR cpp_int_base(literals::detail::value_pack<VALUES...> i)
+         : m_wrapper(i), m_limbs(sizeof...(VALUES)), m_sign(false) {}
+      BOOST_CONSTEXPR cpp_int_base(literals::detail::value_pack<> i)
+         : m_wrapper(i), m_limbs(1), m_sign(false) {}
+      BOOST_CONSTEXPR cpp_int_base(const cpp_int_base& a, const literals::detail::negate_tag&)
+         : m_wrapper(a.m_wrapper), m_limbs(a.m_limbs), m_sign((a.m_limbs == 1) && (*a.limbs() == 0) ? false : !a.m_sign) {}
+#endif
+   //
+   // Helper functions for getting at our internal data, and manipulating storage:
+   //
+   BOOST_MP_FORCEINLINE unsigned size()const BOOST_NOEXCEPT { return m_limbs; }
+   BOOST_MP_FORCEINLINE limb_pointer limbs() BOOST_NOEXCEPT { return m_wrapper.m_data; }
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR const_limb_pointer limbs()const BOOST_NOEXCEPT { return m_wrapper.m_data; }
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR bool sign()const BOOST_NOEXCEPT { return m_sign; }
+   BOOST_MP_FORCEINLINE void sign(bool b) BOOST_NOEXCEPT
+   {
+      m_sign = b;
+      // Check for zero value:
+      if(m_sign && (m_limbs == 1))
+      {
+         if(limbs()[0] == 0)
+            m_sign = false;
+      }
+   }
+   BOOST_MP_FORCEINLINE void resize(unsigned new_size, unsigned min_size) BOOST_NOEXCEPT_IF((Checked == unchecked))
+   {
+      m_limbs = static_cast<boost::uint16_t>((std::min)(new_size, internal_limb_count));
+      detail::verify_new_size(m_limbs, min_size, checked_type());
+   }
+   BOOST_MP_FORCEINLINE void normalize() BOOST_NOEXCEPT_IF((Checked == unchecked))
+   {
+      limb_pointer p = limbs();
+      detail::verify_limb_mask(m_limbs == internal_limb_count, p[internal_limb_count-1], upper_limb_mask, checked_type());
+      p[internal_limb_count-1] &= upper_limb_mask;
+      while((m_limbs-1) && !p[m_limbs - 1])--m_limbs;
+      if((m_limbs == 1) && (!*p)) m_sign = false; // zero is always unsigned
+   }
+
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base() : m_wrapper(limb_type(0u)), m_limbs(1), m_sign(false) {}
+   // Defaulted functions:
+   //BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base(const cpp_int_base& i)BOOST_NOEXCEPT;
+   //~cpp_int_base() BOOST_NOEXCEPT {}
+
+   void assign(const cpp_int_base& o) BOOST_NOEXCEPT
+   {
+      if(this != &o)
+      {
+         resize(o.size(), o.size());
+#if BOOST_WORKAROUND(BOOST_MSVC, >= 1600)
+         std::copy(o.limbs(), o.limbs() + o.size(), stdext::checked_array_iterator<limb_pointer>(limbs(), size()));
+#else
+         std::copy(o.limbs(), o.limbs() + o.size(), limbs());
+#endif
+         m_sign = o.m_sign;
+      }
+   }
+   BOOST_MP_FORCEINLINE void negate() BOOST_NOEXCEPT
+   {
+      m_sign = !m_sign;
+      // Check for zero value:
+      if(m_sign && (m_limbs == 1))
+      {
+         if(limbs()[0] == 0)
+            m_sign = false;
+      }
+   }
+   BOOST_MP_FORCEINLINE bool isneg()const BOOST_NOEXCEPT
+   {
+      return m_sign;
+   }
+   BOOST_MP_FORCEINLINE void do_swap(cpp_int_base& o) BOOST_NOEXCEPT
+   {
+      for(unsigned i = 0; i < (std::max)(size(), o.size()); ++i)
+         std::swap(m_wrapper.m_data[i], o.m_wrapper.m_data[i]);
+      std::swap(m_sign, o.m_sign);
+      std::swap(m_limbs, o.m_limbs);
+   }
+};
+#ifndef BOOST_NO_INCLASS_MEMBER_INITIALIZATION
+
+template <unsigned MinBits, cpp_int_check_type Checked>
+const unsigned cpp_int_base<MinBits, MinBits, signed_magnitude, Checked, void, false>::limb_bits;
+template <unsigned MinBits, cpp_int_check_type Checked>
+const limb_type cpp_int_base<MinBits, MinBits, signed_magnitude, Checked, void, false>::max_limb_value;
+template <unsigned MinBits, cpp_int_check_type Checked>
+const limb_type cpp_int_base<MinBits, MinBits, signed_magnitude, Checked, void, false>::sign_bit_mask;
+template <unsigned MinBits, cpp_int_check_type Checked>
+const unsigned cpp_int_base<MinBits, MinBits, signed_magnitude, Checked, void, false>::internal_limb_count;
+template <unsigned MinBits, cpp_int_check_type Checked>
+const bool cpp_int_base<MinBits, MinBits, signed_magnitude, Checked, void, false>::variable;
+
+#endif
+//
+// Fixed precision (i.e. no allocator), unsigned type with limb-usage count:
+//
+template <unsigned MinBits, cpp_int_check_type Checked>
+struct cpp_int_base<MinBits, MinBits, unsigned_magnitude, Checked, void, false>
+{
+   typedef limb_type*                      limb_pointer;
+   typedef const limb_type*                const_limb_pointer;
+   typedef mpl::int_<Checked>              checked_type;
+
+   //
+   // Interface invariants:
+   //
+   BOOST_STATIC_ASSERT_MSG(MinBits > sizeof(double_limb_type) * CHAR_BIT, "Template parameter MinBits is inconsistent with the parameter trivial - did you mistakingly try to override the trivial parameter?");
+
+public:
+   BOOST_STATIC_CONSTANT(unsigned, limb_bits = sizeof(limb_type) * CHAR_BIT);
+   BOOST_STATIC_CONSTANT(limb_type, max_limb_value = ~static_cast<limb_type>(0u));
+   BOOST_STATIC_CONSTANT(limb_type, sign_bit_mask = 1u << (limb_bits - 1));
+   BOOST_STATIC_CONSTANT(unsigned, internal_limb_count = MinBits / limb_bits + (MinBits % limb_bits ? 1 : 0));
+   BOOST_STATIC_CONSTANT(bool, variable = false);
+   BOOST_STATIC_CONSTANT(limb_type, upper_limb_mask = MinBits % limb_bits ? (limb_type(1) << (MinBits % limb_bits)) -1 : (~limb_type(0)));
+   BOOST_STATIC_ASSERT_MSG(internal_limb_count >= 2, "A fixed precision integer type must have at least 2 limbs");
+
+private:
+   union data_type{
+      limb_type          m_data[internal_limb_count];
+      limb_type          m_first_limb;
+      double_limb_type   m_double_first_limb;
+
+      BOOST_CONSTEXPR data_type() : m_first_limb(0) {}
+      BOOST_CONSTEXPR data_type(limb_type i) : m_first_limb(i) {}
+      BOOST_CONSTEXPR data_type(double_limb_type i) : m_double_first_limb(i) {}
+#if defined(BOOST_MP_USER_DEFINED_LITERALS)
+      template <limb_type...VALUES>
+      BOOST_CONSTEXPR data_type(literals::detail::value_pack<VALUES...>) : m_data{ VALUES... } {}
+#endif
+   } m_wrapper;
+   limb_type          m_limbs;
+
+public:
+   //
+   // Direct construction:
+   //
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base(limb_type i)BOOST_NOEXCEPT
+      : m_wrapper(i), m_limbs(1) {}
+   BOOST_MP_FORCEINLINE cpp_int_base(signed_limb_type i)BOOST_NOEXCEPT_IF((Checked == unchecked))
+      : m_wrapper(limb_type(i < 0 ? -i : i)), m_limbs(1) { if(i < 0) negate(); }
+#ifdef BOOST_LITTLE_ENDIAN
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base(double_limb_type i)BOOST_NOEXCEPT
+      : m_wrapper(i), m_limbs(i > max_limb_value ? 2 : 1) {}
+   BOOST_MP_FORCEINLINE cpp_int_base(signed_double_limb_type i)BOOST_NOEXCEPT_IF((Checked == unchecked))
+      : m_wrapper(double_limb_type(i < 0 ? -i : i)), m_limbs(i < 0 ? (-i > max_limb_value ? 2 : 1) : (i > max_limb_value ? 2 : 1)) { if(i < 0) negate(); }
+#endif
+#if defined(BOOST_MP_USER_DEFINED_LITERALS)
+      template <limb_type...VALUES>
+      BOOST_CONSTEXPR cpp_int_base(literals::detail::value_pack<VALUES...> i)
+         : m_wrapper(i), m_limbs(sizeof...(VALUES)) {}
+      BOOST_CONSTEXPR cpp_int_base(literals::detail::value_pack<>)
+         : m_wrapper(static_cast<limb_type>(0u)), m_limbs(1) {}
+#endif
+   //
+   // Helper functions for getting at our internal data, and manipulating storage:
+   //
+   BOOST_MP_FORCEINLINE unsigned size()const BOOST_NOEXCEPT { return m_limbs; }
+   BOOST_MP_FORCEINLINE limb_pointer limbs() BOOST_NOEXCEPT { return m_wrapper.m_data; }
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR const_limb_pointer limbs()const BOOST_NOEXCEPT { return m_wrapper.m_data; }
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR bool sign()const BOOST_NOEXCEPT { return false; }
+   BOOST_MP_FORCEINLINE void sign(bool b) BOOST_NOEXCEPT_IF((Checked == unchecked)) {  if(b) negate(); }
+   BOOST_MP_FORCEINLINE void resize(unsigned new_size, unsigned min_size) BOOST_NOEXCEPT_IF((Checked == unchecked))
+   {
+      m_limbs = (std::min)(new_size, internal_limb_count);
+      detail::verify_new_size(m_limbs, min_size, checked_type());
+   }
+   BOOST_MP_FORCEINLINE void normalize() BOOST_NOEXCEPT_IF((Checked == unchecked))
+   {
+      limb_pointer p = limbs();
+      detail::verify_limb_mask(m_limbs == internal_limb_count, p[internal_limb_count-1], upper_limb_mask, checked_type());
+      p[internal_limb_count-1] &= upper_limb_mask;
+      while((m_limbs-1) && !p[m_limbs - 1])--m_limbs;
+   }
+
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base() BOOST_NOEXCEPT
+      : m_wrapper(limb_type(0u)), m_limbs(1) {}
+   // Defaulted functions:
+   //BOOST_MP_FORCEINLINE cpp_int_base(const cpp_int_base& o) BOOST_NOEXCEPT;
+   //~cpp_int_base() BOOST_NOEXCEPT {}
+
+   BOOST_MP_FORCEINLINE void assign(const cpp_int_base& o) BOOST_NOEXCEPT
+   {
+      if(this != &o)
+      {
+         resize(o.size(), o.size());
+#if BOOST_WORKAROUND(BOOST_MSVC, >= 1600)
+         std::copy(o.limbs(), o.limbs() + o.size(), stdext::checked_array_iterator<limb_pointer>(limbs(), size()));
+#else
+         std::copy(o.limbs(), o.limbs() + o.size(), limbs());
+#endif
+      }
+   }
+private:
+   void check_negate(const mpl::int_<checked>&)
+   {
+      BOOST_THROW_EXCEPTION(std::range_error("Attempt to negate an unsigned number."));
+   }
+   void check_negate(const mpl::int_<unchecked>&){}
+public:
+   void negate() BOOST_NOEXCEPT_IF((Checked == unchecked))
+   {
+      // Not so much a negate as a complement - this gets called when subtraction
+      // would result in a "negative" number:
+      unsigned i;
+      if((m_limbs == 1) && (m_wrapper.m_data[0] == 0))
+         return; // negating zero is always zero, and always OK.
+      check_negate(checked_type());
+      for(i = m_limbs; i < internal_limb_count; ++i)
+         m_wrapper.m_data[i] = 0;
+      m_limbs = internal_limb_count;
+      for(i = 0; i < internal_limb_count; ++i)
+         m_wrapper.m_data[i] = ~m_wrapper.m_data[i];
+      normalize();
+      eval_increment(static_cast<cpp_int_backend<MinBits, MinBits, unsigned_magnitude, Checked, void>& >(*this));
+   }
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR bool isneg()const BOOST_NOEXCEPT
+   {
+      return false;
+   }
+   BOOST_MP_FORCEINLINE void do_swap(cpp_int_base& o) BOOST_NOEXCEPT
+   {
+      for(unsigned i = 0; i < (std::max)(size(), o.size()); ++i)
+         std::swap(m_wrapper.m_data[i], o.m_wrapper.m_data[i]);
+      std::swap(m_limbs, o.m_limbs);
+   }
+};
+#ifndef BOOST_NO_INCLASS_MEMBER_INITIALIZATION
+
+template <unsigned MinBits, cpp_int_check_type Checked>
+const unsigned cpp_int_base<MinBits, MinBits, unsigned_magnitude, Checked, void, false>::limb_bits;
+template <unsigned MinBits, cpp_int_check_type Checked>
+const limb_type cpp_int_base<MinBits, MinBits, unsigned_magnitude, Checked, void, false>::max_limb_value;
+template <unsigned MinBits, cpp_int_check_type Checked>
+const limb_type cpp_int_base<MinBits, MinBits, unsigned_magnitude, Checked, void, false>::sign_bit_mask;
+template <unsigned MinBits, cpp_int_check_type Checked>
+const unsigned cpp_int_base<MinBits, MinBits, unsigned_magnitude, Checked, void, false>::internal_limb_count;
+template <unsigned MinBits, cpp_int_check_type Checked>
+const bool cpp_int_base<MinBits, MinBits, unsigned_magnitude, Checked, void, false>::variable;
+
+#endif
+//
+// Traits classes to figure out a native type with N bits, these vary from boost::uint_t<N> only
+// because some platforms have native integer types longer than long long, "really long long" anyone??
+//
+template <unsigned N, bool s>
+struct trivial_limb_type_imp
+{
+   typedef double_limb_type type;
+};
+
+template <unsigned N>
+struct trivial_limb_type_imp<N, true>
+{
+   typedef typename boost::uint_t<N>::least type;
+};
+
+template <unsigned N>
+struct trivial_limb_type : public trivial_limb_type_imp<N, N <= sizeof(long long) * CHAR_BIT> {};
+//
+// Backend for fixed precision signed-magnitude type which will fit entirely inside a "double_limb_type":
+//
+template <unsigned MinBits, cpp_int_check_type Checked>
+struct cpp_int_base<MinBits, MinBits, signed_magnitude, Checked, void, true>
+{
+   typedef typename trivial_limb_type<MinBits>::type  local_limb_type;
+   typedef local_limb_type*                           limb_pointer;
+   typedef const local_limb_type*                     const_limb_pointer;
+   typedef mpl::int_<Checked>                         checked_type;
+protected:
+   BOOST_STATIC_CONSTANT(unsigned, limb_bits = sizeof(local_limb_type) * CHAR_BIT);
+   BOOST_STATIC_CONSTANT(local_limb_type, limb_mask = (MinBits < limb_bits) ? local_limb_type((local_limb_type(~local_limb_type(0))) >> (limb_bits - MinBits)) : local_limb_type(~local_limb_type(0)));
+private:
+   local_limb_type    m_data;
+   bool               m_sign;
+
+   //
+   // Interface invariants:
+   //
+   BOOST_STATIC_ASSERT_MSG(MinBits <= sizeof(double_limb_type) * CHAR_BIT, "Template parameter MinBits is inconsistent with the parameter trivial - did you mistakingly try to override the trivial parameter?");
+protected:
+   template <class T>
+   typename boost::disable_if_c<std::numeric_limits<T>::is_specialized && (std::numeric_limits<T>::digits <= (int)MinBits)>::type
+      check_in_range(T val, const mpl::int_<checked>&)
+   {
+      BOOST_MP_USING_ABS
+      typedef typename common_type<T, local_limb_type>::type common_type;
+
+      if(static_cast<common_type>(abs(val)) > static_cast<common_type>(limb_mask))
+         BOOST_THROW_EXCEPTION(std::range_error("The argument to a cpp_int constructor exceeded the largest value it can represent."));
+   }
+   template <class T, int C>
+   void check_in_range(T, const mpl::int_<C>&){}
+
+   template <class T>
+   void check_in_range(T val)
+   {
+      check_in_range(val, checked_type());
+   }
+
+public:
+   //
+   // Direct construction:
+   //
+   template <class SI>
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base(SI i, typename boost::enable_if_c<is_signed<SI>::value && (Checked == unchecked) >::type const* = 0) BOOST_NOEXCEPT_IF((Checked == unchecked))
+      : m_data(i < 0 ? static_cast<local_limb_type>(static_cast<typename make_unsigned<SI>::type>(-i)) & limb_mask : static_cast<local_limb_type>(i) & limb_mask), m_sign(i < 0) {}
+   template <class SI>
+   BOOST_MP_FORCEINLINE cpp_int_base(SI i, typename boost::enable_if_c<is_signed<SI>::value && (Checked == checked) >::type const* = 0) BOOST_NOEXCEPT_IF((Checked == unchecked))
+      : m_data(i < 0 ? static_cast<local_limb_type>(static_cast<typename make_unsigned<SI>::type>(-i) & limb_mask) : static_cast<local_limb_type>(i) & limb_mask), m_sign(i < 0) { check_in_range(i); }
+   template <class UI>
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base(UI i, typename boost::enable_if_c<is_unsigned<UI>::value && (Checked == unchecked)>::type const* = 0) BOOST_NOEXCEPT_IF((Checked == unchecked))
+      : m_data(static_cast<local_limb_type>(i) & limb_mask), m_sign(false) {}
+   template <class UI>
+   BOOST_MP_FORCEINLINE cpp_int_base(UI i, typename boost::enable_if_c<is_unsigned<UI>::value && (Checked == checked)>::type const* = 0) BOOST_NOEXCEPT_IF((Checked == unchecked))
+      : m_data(static_cast<local_limb_type>(i) & limb_mask), m_sign(false) { check_in_range(i); }
+   template <class F>
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base(F i, typename boost::enable_if_c<is_floating_point<F>::value && (Checked == unchecked)>::type const* = 0) BOOST_NOEXCEPT_IF((Checked == unchecked))
+      : m_data(static_cast<local_limb_type>(std::fabs(i)) & limb_mask), m_sign(i < 0) {}
+   template <class F>
+   BOOST_MP_FORCEINLINE cpp_int_base(F i, typename boost::enable_if_c<is_floating_point<F>::value && (Checked == checked)>::type const* = 0) BOOST_NOEXCEPT_IF((Checked == unchecked))
+      : m_data(static_cast<local_limb_type>(std::fabs(i)) & limb_mask), m_sign(i < 0) { check_in_range(i); }
+#if defined(BOOST_MP_USER_DEFINED_LITERALS)
+      BOOST_CONSTEXPR cpp_int_base(literals::detail::value_pack<>)
+         : m_data(static_cast<local_limb_type>(0u)), m_sign(false) {}
+      template <limb_type a>
+      BOOST_CONSTEXPR cpp_int_base(literals::detail::value_pack<a>)
+         : m_data(static_cast<local_limb_type>(a)), m_sign(false) {}
+      template <limb_type a, limb_type b>
+      BOOST_CONSTEXPR cpp_int_base(literals::detail::value_pack<a, b>)
+         : m_data(static_cast<local_limb_type>(a) | (static_cast<local_limb_type>(b) << bits_per_limb)), m_sign(false) {}
+      BOOST_CONSTEXPR cpp_int_base(const cpp_int_base& a, const literals::detail::negate_tag&)
+         : m_data(a.m_data), m_sign(a.m_data ? !a.m_sign : false) {}
+#endif
+   //
+   // Helper functions for getting at our internal data, and manipulating storage:
+   //
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR unsigned size()const BOOST_NOEXCEPT { return 1; }
+   BOOST_MP_FORCEINLINE limb_pointer limbs() BOOST_NOEXCEPT { return &m_data; }
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR const_limb_pointer limbs()const BOOST_NOEXCEPT { return &m_data; }
+   BOOST_MP_FORCEINLINE bool sign()const BOOST_NOEXCEPT { return m_sign; }
+   BOOST_MP_FORCEINLINE void sign(bool b) BOOST_NOEXCEPT
+   {
+      m_sign = b;
+      // Check for zero value:
+      if(m_sign && !m_data)
+      {
+         m_sign = false;
+      }
+   }
+   BOOST_MP_FORCEINLINE void resize(unsigned new_size, unsigned min_size)
+   {
+      detail::verify_new_size(2, min_size, checked_type());
+   }
+   BOOST_MP_FORCEINLINE void normalize() BOOST_NOEXCEPT_IF((Checked == unchecked))
+   {
+      if(!m_data)
+         m_sign = false; // zero is always unsigned
+      detail::verify_limb_mask(true, m_data, limb_mask, checked_type());
+      m_data &= limb_mask;
+   }
+
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base() : m_data(0), m_sign(false) {}
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base(const cpp_int_base& o) BOOST_NOEXCEPT
+      : m_data(o.m_data), m_sign(o.m_sign) {}
+   //~cpp_int_base() BOOST_NOEXCEPT {}
+   BOOST_MP_FORCEINLINE void assign(const cpp_int_base& o) BOOST_NOEXCEPT
+   {
+      m_data = o.m_data;
+      m_sign = o.m_sign;
+   }
+   BOOST_MP_FORCEINLINE void negate() BOOST_NOEXCEPT
+   {
+      m_sign = !m_sign;
+      // Check for zero value:
+      if(m_data == 0)
+      {
+         m_sign = false;
+      }
+   }
+   BOOST_MP_FORCEINLINE bool isneg()const BOOST_NOEXCEPT
+   {
+      return m_sign;
+   }
+   BOOST_MP_FORCEINLINE void do_swap(cpp_int_base& o) BOOST_NOEXCEPT
+   {
+      std::swap(m_sign, o.m_sign);
+      std::swap(m_data, o.m_data);
+   }
+};
+//
+// Backend for unsigned fixed precision (i.e. no allocator) type which will fit entirely inside a "double_limb_type":
+//
+template <unsigned MinBits, cpp_int_check_type Checked>
+struct cpp_int_base<MinBits, MinBits, unsigned_magnitude, Checked, void, true>
+{
+   typedef typename trivial_limb_type<MinBits>::type  local_limb_type;
+   typedef local_limb_type*                           limb_pointer;
+   typedef const local_limb_type*                     const_limb_pointer;
+private:
+   BOOST_STATIC_CONSTANT(unsigned, limb_bits = sizeof(local_limb_type) * CHAR_BIT);
+   BOOST_STATIC_CONSTANT(local_limb_type, limb_mask = limb_bits != MinBits ? 
+      static_cast<local_limb_type>(static_cast<local_limb_type>(~local_limb_type(0)) >> (limb_bits - MinBits))
+      : static_cast<local_limb_type>(~local_limb_type(0)));
+
+   local_limb_type    m_data;
+
+   typedef mpl::int_<Checked>                          checked_type;
+
+   //
+   // Interface invariants:
+   //
+   BOOST_STATIC_ASSERT_MSG(MinBits <= sizeof(double_limb_type) * CHAR_BIT, "Template parameter MinBits is inconsistent with the parameter trivial - did you mistakingly try to override the trivial parameter?");
+protected:
+   template <class T>
+   typename boost::disable_if_c<std::numeric_limits<T>::is_specialized && (std::numeric_limits<T>::digits <= (int)MinBits)>::type
+      check_in_range(T val, const mpl::int_<checked>&, const mpl::false_&)
+   {
+      typedef typename common_type<T, local_limb_type>::type common_type;
+
+      if(static_cast<common_type>(val) > limb_mask)
+         BOOST_THROW_EXCEPTION(std::range_error("The argument to a cpp_int constructor exceeded the largest value it can represent."));
+   }
+   template <class T>
+   void check_in_range(T val, const mpl::int_<checked>&, const mpl::true_&)
+   {
+      typedef typename common_type<T, local_limb_type>::type common_type;
+
+      if(static_cast<common_type>(val) > limb_mask)
+         BOOST_THROW_EXCEPTION(std::range_error("The argument to a cpp_int constructor exceeded the largest value it can represent."));
+      if(val < 0)
+         BOOST_THROW_EXCEPTION(std::range_error("The argument to an unsigned cpp_int constructor was negative."));
+   }
+   template <class T, int C, bool B>
+   BOOST_MP_FORCEINLINE void check_in_range(T, const mpl::int_<C>&, const mpl::bool_<B>&){}
+
+   template <class T>
+   BOOST_MP_FORCEINLINE void check_in_range(T val)
+   {
+      check_in_range(val, checked_type(), is_signed<T>());
+   }
+
+public:
+   //
+   // Direct construction:
+   //
+   template <class SI>
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base(SI i, typename boost::enable_if_c<is_signed<SI>::value && (Checked == unchecked) >::type const* = 0) BOOST_NOEXCEPT_IF((Checked == unchecked))
+      : m_data(i < 0 ? (1 + ~static_cast<local_limb_type>(-i)) & limb_mask : static_cast<local_limb_type>(i) & limb_mask) {}
+   template <class SI>
+   BOOST_MP_FORCEINLINE cpp_int_base(SI i, typename boost::enable_if_c<is_signed<SI>::value && (Checked == checked) >::type const* = 0) BOOST_NOEXCEPT_IF((Checked == unchecked))
+      : m_data(i < 0 ? 1 + ~static_cast<local_limb_type>(-i) : static_cast<local_limb_type>(i)) { check_in_range(i); }
+   template <class UI>
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base(UI i, typename boost::enable_if_c<is_unsigned<UI>::value && (Checked == unchecked) >::type const* = 0) BOOST_NOEXCEPT_IF((Checked == unchecked))
+      : m_data(static_cast<local_limb_type>(i) & limb_mask) {}
+   template <class UI>
+   BOOST_MP_FORCEINLINE cpp_int_base(UI i, typename boost::enable_if_c<is_unsigned<UI>::value && (Checked == checked) >::type const* = 0) BOOST_NOEXCEPT_IF((Checked == unchecked))
+      : m_data(static_cast<local_limb_type>(i)) { check_in_range(i); }
+   template <class F>
+   BOOST_MP_FORCEINLINE cpp_int_base(F i, typename boost::enable_if<is_floating_point<F> >::type const* = 0) BOOST_NOEXCEPT_IF((Checked == unchecked))
+      : m_data(static_cast<local_limb_type>(std::fabs(i)) & limb_mask)
+   {
+      check_in_range(i);
+      if(i < 0)
+         negate();
+   }
+#if defined(BOOST_MP_USER_DEFINED_LITERALS)
+      BOOST_CONSTEXPR cpp_int_base(literals::detail::value_pack<>)
+         : m_data(static_cast<local_limb_type>(0u)) {}
+      template <limb_type a>
+      BOOST_CONSTEXPR cpp_int_base(literals::detail::value_pack<a>)
+         : m_data(static_cast<local_limb_type>(a)) {}
+      template <limb_type a, limb_type b>
+      BOOST_CONSTEXPR cpp_int_base(literals::detail::value_pack<a, b>)
+         : m_data(static_cast<local_limb_type>(a) | (static_cast<local_limb_type>(b) << bits_per_limb)) {}
+#endif
+   //
+   // Helper functions for getting at our internal data, and manipulating storage:
+   //
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR unsigned size()const BOOST_NOEXCEPT { return 1; }
+   BOOST_MP_FORCEINLINE limb_pointer limbs() BOOST_NOEXCEPT { return &m_data; }
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR const_limb_pointer limbs()const BOOST_NOEXCEPT { return &m_data; }
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR bool sign()const BOOST_NOEXCEPT { return false; }
+   BOOST_MP_FORCEINLINE void sign(bool b) BOOST_NOEXCEPT_IF((Checked == unchecked))
+   {
+      if(b)
+         negate();
+   }
+   BOOST_MP_FORCEINLINE void resize(unsigned new_size, unsigned min_size)
+   {
+      detail::verify_new_size(2, min_size, checked_type());
+   }
+   BOOST_MP_FORCEINLINE void normalize() BOOST_NOEXCEPT_IF((Checked == unchecked))
+   {
+      detail::verify_limb_mask(true, m_data, limb_mask, checked_type());
+      m_data &= limb_mask;
+   }
+
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base() : m_data(0) {}
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_base(const cpp_int_base& o) BOOST_NOEXCEPT
+      : m_data(o.m_data) {}
+   //~cpp_int_base() BOOST_NOEXCEPT {}
+   BOOST_MP_FORCEINLINE void assign(const cpp_int_base& o) BOOST_NOEXCEPT
+   {
+      m_data = o.m_data;
+   }
+   BOOST_MP_FORCEINLINE void negate() BOOST_NOEXCEPT_IF((Checked == unchecked))
+   {
+      if(Checked == checked)
+      {
+         BOOST_THROW_EXCEPTION(std::range_error("Attempt to negate an unsigned type."));
+      }
+      m_data = ~m_data;
+      ++m_data;
+   }
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR bool isneg()const BOOST_NOEXCEPT
+   {
+      return false;
+   }
+   BOOST_MP_FORCEINLINE void do_swap(cpp_int_base& o) BOOST_NOEXCEPT
+   {
+      std::swap(m_data, o.m_data);
+   }
+};
+//
+// Traits class, lets us know whether type T can be directly converted to the base type,
+// used to enable/disable constructors etc:
+//
+template <class Arg, class Base>
+struct is_allowed_cpp_int_base_conversion : public mpl::if_c<
+      is_same<Arg, limb_type>::value || is_same<Arg, signed_limb_type>::value
+#ifdef BOOST_LITTLE_ENDIAN
+      || is_same<Arg, double_limb_type>::value || is_same<Arg, signed_double_limb_type>::value
+#endif
+#if defined(BOOST_MP_USER_DEFINED_LITERALS)
+      || literals::detail::is_value_pack<Arg>::value
+#endif
+      || (is_trivial_cpp_int<Base>::value && is_arithmetic<Arg>::value),
+      mpl::true_,
+      mpl::false_
+   >::type
+{};
+//
+// Now the actual backend, normalising parameters passed to the base class:
+//
+template <unsigned MinBits, unsigned MaxBits, cpp_integer_type SignType, cpp_int_check_type Checked, class Allocator>
+struct cpp_int_backend
+   : public cpp_int_base<
+               min_precision<cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator> >::value,
+               max_precision<cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator> >::value,
+               SignType,
+               Checked,
+               Allocator,
+               is_trivial_cpp_int<cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator> >::value>
+{
+   typedef cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator>    self_type;
+   typedef cpp_int_base<
+               min_precision<self_type>::value,
+               max_precision<self_type>::value,
+               SignType,
+               Checked,
+               Allocator,
+               is_trivial_cpp_int<self_type>::value>                 base_type;
+   typedef mpl::bool_<is_trivial_cpp_int<self_type>::value>          trivial_tag;
+public:
+   typedef typename mpl::if_<
+      trivial_tag,
+      mpl::list<
+      signed char, short, int, long,
+      long long, signed_double_limb_type>,
+      mpl::list<signed_limb_type, signed_double_limb_type>
+   >::type                                                           signed_types;
+   typedef typename mpl::if_<
+      trivial_tag,
+      mpl::list<unsigned char, unsigned short, unsigned,
+      unsigned long long, double_limb_type>,
+      mpl::list<limb_type, double_limb_type>
+   >::type                                                           unsigned_types;
+   typedef typename mpl::if_<
+      trivial_tag,
+      mpl::list<float, double, long double>,
+      mpl::list<long double>
+   >::type                                                           float_types;
+   typedef mpl::int_<Checked>                                        checked_type;
+
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_backend() BOOST_NOEXCEPT{}
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_backend(const cpp_int_backend& o) BOOST_NOEXCEPT_IF(boost::is_void<Allocator>::value) : base_type(o) {}
+#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_backend(cpp_int_backend&& o) BOOST_NOEXCEPT
+      : base_type(static_cast<base_type&&>(o)) {}
+#endif
+   //
+   // Direct construction from arithmetic type:
+   //
+   template <class Arg>
+   BOOST_MP_FORCEINLINE BOOST_CONSTEXPR cpp_int_backend(Arg i, typename boost::enable_if_c<is_allowed_cpp_int_base_conversion<Arg, base_type>::value >::type const* = 0)BOOST_NOEXCEPT_IF((Checked == unchecked) && boost::is_void<Allocator>::value)
+      : base_type(i) {}
+
+private:
+   template <unsigned MinBits2, unsigned MaxBits2, cpp_integer_type SignType2, cpp_int_check_type Checked2, class Allocator2>
+   void do_assign(const cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2>& other, mpl::true_ const&, mpl::true_ const &)
+   {
+      // Assigning trivial type to trivial type:
+      this->check_in_range(*other.limbs());
+      *this->limbs() = static_cast<typename self_type::local_limb_type>(*other.limbs());
+      this->sign(other.sign());
+      this->normalize();
+   }
+   template <unsigned MinBits2, unsigned MaxBits2, cpp_integer_type SignType2, cpp_int_check_type Checked2, class Allocator2>
+   void do_assign(const cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2>& other, mpl::true_ const&, mpl::false_ const &)
+   {
+      // non-trivial to trivial narrowing conversion:
+      double_limb_type v = *other.limbs();
+      if(other.size() > 1)
+      {
+         v |= static_cast<double_limb_type>(other.limbs()[1]) << bits_per_limb;
+         if((Checked == checked) && (other.size() > 2))
+         {
+            BOOST_THROW_EXCEPTION(std::range_error("Assignment of a cpp_int that is out of range for the target type."));
+         }
+      }
+      *this = v;
+      this->sign(other.sign());
+      this->normalize();
+   }
+   template <unsigned MinBits2, unsigned MaxBits2, cpp_integer_type SignType2, cpp_int_check_type Checked2, class Allocator2>
+   void do_assign(const cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2>& other, mpl::false_ const&, mpl::true_ const &)
+   {
+      // trivial to non-trivial, treat the trivial argument as if it were an unsigned arithmetic type, then set the sign afterwards:
+       *this = static_cast<
+            typename boost::multiprecision::detail::canonical<
+               typename cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2>::local_limb_type,
+               cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator>
+            >::type
+         >(*other.limbs());
+       this->sign(other.sign());
+   }
+   template <unsigned MinBits2, unsigned MaxBits2, cpp_integer_type SignType2, cpp_int_check_type Checked2, class Allocator2>
+   void do_assign(const cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2>& other, mpl::false_ const&, mpl::false_ const &)
+   {
+      // regular non-trivial to non-trivial assign:
+      this->resize(other.size(), other.size());
+#if BOOST_WORKAROUND(BOOST_MSVC, >= 1600)
+      std::copy(other.limbs(), other.limbs() + (std::min)(other.size(), this->size()), stdext::checked_array_iterator<limb_pointer>(this->limbs(), this->size()));
+#else
+      std::copy(other.limbs(), other.limbs() + (std::min)(other.size(), this->size()), this->limbs());
+#endif
+      this->sign(other.sign());
+      this->normalize();
+   }
+public:
+   template <unsigned MinBits2, unsigned MaxBits2, cpp_integer_type SignType2, cpp_int_check_type Checked2, class Allocator2>
+   cpp_int_backend(
+      const cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2>& other,
+      typename boost::enable_if_c<is_implicit_cpp_int_conversion<cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2>, self_type>::value>::type* = 0)
+      : base_type()
+   {
+      do_assign(
+         other,
+         mpl::bool_<is_trivial_cpp_int<self_type>::value>(),
+         mpl::bool_<is_trivial_cpp_int<cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2> >::value>());
+   }
+   template <unsigned MinBits2, unsigned MaxBits2, cpp_integer_type SignType2, cpp_int_check_type Checked2, class Allocator2>
+   explicit cpp_int_backend(
+      const cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2>& other,
+      typename boost::disable_if_c<is_implicit_cpp_int_conversion<cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2>, self_type>::value>::type* = 0)
+      : base_type()
+   {
+      do_assign(
+         other,
+         mpl::bool_<is_trivial_cpp_int<self_type>::value>(),
+         mpl::bool_<is_trivial_cpp_int<cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2> >::value>());
+   }
+   template <unsigned MinBits2, unsigned MaxBits2, cpp_integer_type SignType2, cpp_int_check_type Checked2, class Allocator2>
+   cpp_int_backend& operator=(
+      const cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2>& other)
+   {
+      do_assign(
+         other,
+         mpl::bool_<is_trivial_cpp_int<self_type>::value>(),
+         mpl::bool_<is_trivial_cpp_int<cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2> >::value>());
+      return *this;
+   }
+#ifdef BOOST_MP_USER_DEFINED_LITERALS
+   BOOST_CONSTEXPR cpp_int_backend(const cpp_int_backend& a, const literals::detail::negate_tag& tag)
+      : base_type(static_cast<const base_type&>(a), tag){}
+#endif
+
+   BOOST_MP_FORCEINLINE cpp_int_backend& operator = (const cpp_int_backend& o) BOOST_NOEXCEPT_IF((Checked == unchecked) && boost::is_void<Allocator>::value)
+   {
+      this->assign(o);
+      return *this;
+   }
+#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
+   BOOST_MP_FORCEINLINE cpp_int_backend& operator = (cpp_int_backend&& o) BOOST_NOEXCEPT_IF(boost::is_void<Allocator>::value)
+   {
+      *static_cast<base_type*>(this) = static_cast<base_type&&>(o);
+      return *this;
+   }
+#endif
+private:
+   template <class A>
+   typename boost::enable_if<is_unsigned<A> >::type do_assign_arithmetic(A val, const mpl::true_&)
+   {
+      this->check_in_range(val);
+      *this->limbs() = static_cast<typename self_type::local_limb_type>(val);
+      this->normalize();
+   }
+   template <class A>
+   typename boost::disable_if<is_unsigned<A> >::type do_assign_arithmetic(A val, const mpl::true_&)
+   {
+      typedef typename make_signed<typename self_type::local_limb_type>::type signed_limb_type;
+      this->check_in_range(val);
+      *this->limbs() = (val < 0) ? static_cast<typename self_type::local_limb_type>(-static_cast<signed_limb_type>(val)) : static_cast<typename self_type::local_limb_type>(val);
+      this->sign(val < 0);
+      this->normalize();
+   }
+   BOOST_MP_FORCEINLINE void do_assign_arithmetic(limb_type i, const mpl::false_&) BOOST_NOEXCEPT
+   {
+      this->resize(1, 1);
+      *this->limbs() = i;
+      this->sign(false);
+   }
+   BOOST_MP_FORCEINLINE void do_assign_arithmetic(signed_limb_type i, const mpl::false_&) BOOST_NOEXCEPT_IF((Checked == unchecked))
+   {
+      this->resize(1, 1);
+      *this->limbs() = static_cast<limb_type>(std::abs(i));
+      this->sign(i < 0);
+   }
+   void do_assign_arithmetic(double_limb_type i, const mpl::false_&)
+   {
+      BOOST_STATIC_ASSERT(sizeof(i) == 2 * sizeof(limb_type));
+      BOOST_STATIC_ASSERT(base_type::internal_limb_count >= 2);
+      typename base_type::limb_pointer p = this->limbs();
+      *p = static_cast<limb_type>(i);
+      p[1] = static_cast<limb_type>(i >> base_type::limb_bits);
+      this->resize(p[1] ? 2 : 1, p[1] ? 2 : 1);
+      this->sign(false);
+   }
+   void do_assign_arithmetic(signed_double_limb_type i, const mpl::false_&)
+   {
+      BOOST_STATIC_ASSERT(sizeof(i) == 2 * sizeof(limb_type));
+      BOOST_STATIC_ASSERT(base_type::internal_limb_count >= 2);
+      bool s = false;
+      if(i < 0)
+      {
+         s = true;
+         i = -i;
+      }
+      else
+         this->sign(false);
+      typename base_type::limb_pointer p = this->limbs();
+      *p = static_cast<limb_type>(i);
+      p[1] = static_cast<limb_type>(i >> base_type::limb_bits);
+      this->resize(p[1] ? 2 : 1, p[1] ? 2 : 1);
+      this->sign(s);
+   }
+
+   void do_assign_arithmetic(long double a, const mpl::false_&)
+   {
+      using default_ops::eval_add;
+      using default_ops::eval_subtract;
+      using std::frexp;
+      using std::ldexp;
+      using std::floor;
+
+      if (a == 0) {
+         *this = static_cast<limb_type>(0u);
+      }
+
+      if (a == 1) {
+         *this = static_cast<limb_type>(1u);
+      }
+
+      BOOST_ASSERT(!(boost::math::isinf)(a));
+      BOOST_ASSERT(!(boost::math::isnan)(a));
+
+      int e;
+      long double f, term;
+      *this = static_cast<limb_type>(0u);
+
+      f = frexp(a, &e);
+
+      static const limb_type shift = std::numeric_limits<limb_type>::digits;
+
+      while(f)
+      {
+         // extract int sized bits from f:
+         f = ldexp(f, shift);
+         term = floor(f);
+         e -= shift;
+         eval_left_shift(*this, shift);
+         if(term > 0)
+            eval_add(*this, static_cast<limb_type>(term));
+         else
+            eval_subtract(*this, static_cast<limb_type>(-term));
+         f -= term;
+      }
+      if(e > 0)
+         eval_left_shift(*this, e);
+      else if(e < 0)
+         eval_right_shift(*this, -e);
+   }
+public:
+   template <class Arithmetic>
+   BOOST_MP_FORCEINLINE cpp_int_backend& operator = (Arithmetic val)
+   {
+      do_assign_arithmetic(val, trivial_tag());
+      return *this;
+   }
+private:
+   void do_assign_string(const char* s, const mpl::true_&)
+   {
+      std::size_t n = s ? std::strlen(s) : 0;
+      *this->limbs() = 0;
+      unsigned radix = 10;
+      bool isneg = false;
+      if(n && (*s == '-'))
+      {
+         --n;
+         ++s;
+         isneg = true;
+      }
+      if(n && (*s == '0'))
+      {
+         if((n > 1) && ((s[1] == 'x') || (s[1] == 'X')))
+         {
+            radix = 16;
+            s +=2;
+            n -= 2;
+         }
+         else
+         {
+            radix = 8;
+            n -= 1;
+         }
+      }
+      if(n)
+      {
+         unsigned val;
+         while(*s)
+         {
+            if(*s >= '0' && *s <= '9')
+               val = *s - '0';
+            else if(*s >= 'a' && *s <= 'f')
+               val = 10 + *s - 'a';
+            else if(*s >= 'A' && *s <= 'F')
+               val = 10 + *s - 'A';
+            else
+               val = radix + 1;
+            if(val >= radix)
+            {
+               BOOST_THROW_EXCEPTION(std::runtime_error("Unexpected content found while parsing character string."));
+            }
+            *this->limbs() = detail::checked_multiply(*this->limbs(), static_cast<typename base_type::local_limb_type>(radix), checked_type());
+            *this->limbs() = detail::checked_add(*this->limbs(), static_cast<typename base_type::local_limb_type>(val), checked_type());
+            ++s;
+         }
+      }
+      if(isneg)
+         this->negate();
+   }
+   void do_assign_string(const char* s, const mpl::false_&)
+   {
+      using default_ops::eval_multiply;
+      using default_ops::eval_add;
+      std::size_t n = s ? std::strlen(s) : 0;
+      *this = static_cast<limb_type>(0u);
+      unsigned radix = 10;
+      bool isneg = false;
+      if(n && (*s == '-'))
+      {
+         --n;
+         ++s;
+         isneg = true;
+      }
+      if(n && (*s == '0'))
+      {
+         if((n > 1) && ((s[1] == 'x') || (s[1] == 'X')))
+         {
+            radix = 16;
+            s +=2;
+            n -= 2;
+         }
+         else
+         {
+            radix = 8;
+            n -= 1;
+         }
+      }
+      if(n)
+      {
+         if(radix == 8 || radix == 16)
+         {
+            unsigned shift = radix == 8 ? 3 : 4;
+            unsigned block_count = base_type::limb_bits / shift;
+            unsigned block_shift = shift * block_count;
+            limb_type val, block;
+            while(*s)
+            {
+               block = 0;
+               for(unsigned i = 0; (i < block_count); ++i)
+               {
+                  if(*s >= '0' && *s <= '9')
+                     val = *s - '0';
+                  else if(*s >= 'a' && *s <= 'f')
+                     val = 10 + *s - 'a';
+                  else if(*s >= 'A' && *s <= 'F')
+                     val = 10 + *s - 'A';
+                  else
+                     val = base_type::max_limb_value;
+                  if(val >= radix)
+                  {
+                     BOOST_THROW_EXCEPTION(std::runtime_error("Unexpected content found while parsing character string."));
+                  }
+                  block <<= shift;
+                  block |= val;
+                  if(!*++s)
+                  {
+                     // final shift is different:
+                     block_shift = (i + 1) * shift;
+                     break;
+                  }
+               }
+               eval_left_shift(*this, block_shift);
+               this->limbs()[0] |= block;
+            }
+         }
+         else
+         {
+            // Base 10, we extract blocks of size 10^9 at a time, that way
+            // the number of multiplications is kept to a minimum:
+            limb_type block_mult = max_block_10;
+            while(*s)
+            {
+               limb_type block = 0;
+               for(unsigned i = 0; i < digits_per_block_10; ++i)
+               {
+                  limb_type val;
+                  if(*s >= '0' && *s <= '9')
+                     val = *s - '0';
+                  else
+                     BOOST_THROW_EXCEPTION(std::runtime_error("Unexpected character encountered in input."));
+                  block *= 10;
+                  block += val;
+                  if(!*++s)
+                  {
+                     block_mult = block_multiplier(i);
+                     break;
+                  }
+               }
+               eval_multiply(*this, block_mult);
+               eval_add(*this, block);
+            }
+         }
+      }
+      if(isneg)
+         this->negate();
+   }
+public:
+   cpp_int_backend& operator = (const char* s)
+   {
+      do_assign_string(s, trivial_tag());
+      return *this;
+   }
+   BOOST_MP_FORCEINLINE void swap(cpp_int_backend& o) BOOST_NOEXCEPT
+   {
+      this->do_swap(o);
+   }
+private:
+   std::string do_get_trivial_string(std::ios_base::fmtflags f, const mpl::false_&)const
+   {
+      typedef typename mpl::if_c<sizeof(*this->limbs()) == 1, unsigned, typename base_type::local_limb_type>::type io_type;
+      if(this->sign() && (((f & std::ios_base::hex) == std::ios_base::hex) || ((f & std::ios_base::oct) == std::ios_base::oct)))
+         BOOST_THROW_EXCEPTION(std::runtime_error("Base 8 or 16 printing of negative numbers is not supported."));
+      std::stringstream ss;
+      ss.flags(f & ~std::ios_base::showpos);
+      ss << static_cast<io_type>(*this->limbs());
+      std::string result;
+      if(this->sign())
+         result += '-';
+      else if(f & std::ios_base::showpos)
+         result += '+';
+      result += ss.str();
+      return result;
+   }
+   std::string do_get_trivial_string(std::ios_base::fmtflags f, const mpl::true_&)const
+   {
+      // Even though we have only one limb, we can't do IO on it :-(
+      int base = 10;
+      if((f & std::ios_base::oct) == std::ios_base::oct)
+         base = 8;
+      else if((f & std::ios_base::hex) == std::ios_base::hex)
+         base = 16;
+      std::string result;
+
+      unsigned Bits = sizeof(typename base_type::local_limb_type) * CHAR_BIT;
+
+      if(base == 8 || base == 16)
+      {
+         if(this->sign())
+            BOOST_THROW_EXCEPTION(std::runtime_error("Base 8 or 16 printing of negative numbers is not supported."));
+         limb_type shift = base == 8 ? 3 : 4;
+         limb_type mask = static_cast<limb_type>((1u << shift) - 1);
+         typename base_type::local_limb_type v = *this->limbs();
+         result.assign(Bits / shift + (Bits % shift ? 1 : 0), '0');
+         std::string::difference_type pos = result.size() - 1;
+         for(unsigned i = 0; i < Bits / shift; ++i)
+         {
+            char c = '0' + static_cast<char>(v & mask);
+            if(c > '9')
+               c += 'A' - '9' - 1;
+            result[pos--] = c;
+            v >>= shift;
+         }
+         if(Bits % shift)
+         {
+            mask = static_cast<limb_type>((1u << (Bits % shift)) - 1);
+            char c = '0' + static_cast<char>(v & mask);
+            if(c > '9')
+               c += 'A' - '9';
+            result[pos] = c;
+         }
+         //
+         // Get rid of leading zeros:
+         //
+         std::string::size_type n = result.find_first_not_of('0');
+         if(!result.empty() && (n == std::string::npos))
+            n = result.size() - 1;
+         result.erase(0, n);
+         if(f & std::ios_base::showbase)
+         {
+            const char* pp = base == 8 ? "0" : "0x";
+            result.insert(0, pp);
+         }
+      }
+      else
+      {
+         result.assign(Bits / 3 + 1, '0');
+         std::string::difference_type pos = result.size() - 1;
+         typename base_type::local_limb_type v(*this->limbs());
+         bool neg = false;
+         if(this->sign())
+         {
+            neg = true;
+         }
+         while(v)
+         {
+            result[pos] = (v % 10) + '0';
+            --pos;
+            v /= 10;
+         }
+         std::string::size_type n = result.find_first_not_of('0');
+         result.erase(0, n);
+         if(result.empty())
+            result = "0";
+         if(neg)
+            result.insert(0, 1, '-');
+         else if(f & std::ios_base::showpos)
+            result.insert(0, 1, '+');
+      }
+      return result;
+   }
+   std::string do_get_string(std::ios_base::fmtflags f, const mpl::true_&)const
+   {
+#ifdef BOOST_MP_NO_DOUBLE_LIMB_TYPE_IO
+      return do_get_trivial_string(f, mpl::bool_<is_same<typename base_type::local_limb_type, double_limb_type>::value>());
+#else
+      return do_get_trivial_string(f, mpl::bool_<false>());
+#endif
+   }
+   std::string do_get_string(std::ios_base::fmtflags f, const mpl::false_&)const
+   {
+      using default_ops::eval_get_sign;
+      int base = 10;
+      if((f & std::ios_base::oct) == std::ios_base::oct)
+         base = 8;
+      else if((f & std::ios_base::hex) == std::ios_base::hex)
+         base = 16;
+      std::string result;
+
+      unsigned Bits = this->size() * base_type::limb_bits;
+
+      if(base == 8 || base == 16)
+      {
+         if(this->sign())
+            BOOST_THROW_EXCEPTION(std::runtime_error("Base 8 or 16 printing of negative numbers is not supported."));
+         limb_type shift = base == 8 ? 3 : 4;
+         limb_type mask = static_cast<limb_type>((1u << shift) - 1);
+         cpp_int_backend t(*this);
+         result.assign(Bits / shift + (Bits % shift ? 1 : 0), '0');
+         std::string::difference_type pos = result.size() - 1;
+         for(unsigned i = 0; i < Bits / shift; ++i)
+         {
+            char c = '0' + static_cast<char>(t.limbs()[0] & mask);
+            if(c > '9')
+               c += 'A' - '9' - 1;
+            result[pos--] = c;
+            eval_right_shift(t, shift);
+         }
+         if(Bits % shift)
+         {
+            mask = static_cast<limb_type>((1u << (Bits % shift)) - 1);
+            char c = '0' + static_cast<char>(t.limbs()[0] & mask);
+            if(c > '9')
+               c += 'A' - '9';
+            result[pos] = c;
+         }
+         //
+         // Get rid of leading zeros:
+         //
+         std::string::size_type n = result.find_first_not_of('0');
+         if(!result.empty() && (n == std::string::npos))
+            n = result.size() - 1;
+         result.erase(0, n);
+         if(f & std::ios_base::showbase)
+         {
+            const char* pp = base == 8 ? "0" : "0x";
+            result.insert(0, pp);
+         }
+      }
+      else
+      {
+         result.assign(Bits / 3 + 1, '0');
+         std::string::difference_type pos = result.size() - 1;
+         cpp_int_backend t(*this);
+         cpp_int_backend r;
+         bool neg = false;
+         if(t.sign())
+         {
+            t.negate();
+            neg = true;
+         }
+         if(this->size() == 1)
+         {
+            result = boost::lexical_cast<std::string>(t.limbs()[0]);
+         }
+         else
+         {
+            cpp_int_backend block10;
+            block10 = max_block_10;
+            while(eval_get_sign(t) != 0)
+            {
+               cpp_int_backend t2;
+               divide_unsigned_helper(&t2, t, block10, r);
+               t = t2;
+               limb_type v = r.limbs()[0];
+               for(unsigned i = 0; i < digits_per_block_10; ++i)
+               {
+                  char c = '0' + v % 10;
+                  v /= 10;
+                  result[pos] = c;
+                  if(pos-- == 0)
+                     break;
+               }
+            }
+         }
+         std::string::size_type n = result.find_first_not_of('0');
+         result.erase(0, n);
+         if(result.empty())
+            result = "0";
+         if(neg)
+            result.insert(0, 1, '-');
+         else if(f & std::ios_base::showpos)
+            result.insert(0, 1, '+');
+      }
+      return result;
+   }
+public:
+   std::string str(std::streamsize /*digits*/, std::ios_base::fmtflags f)const
+   {
+      return do_get_string(f, trivial_tag());
+   }
+   template <unsigned MinBits2, unsigned MaxBits2, cpp_integer_type SignType2, cpp_int_check_type Checked2, class Allocator2>
+   int compare_imp(const cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2>& o, const mpl::false_&, const mpl::false_&)const BOOST_NOEXCEPT
+   {
+      if(this->sign() != o.sign())
+         return this->sign() ? -1 : 1;
+
+      // Only do the compare if the same sign:
+      int result = compare_unsigned(o);
+
+      if(this->sign())
+         result = -result;
+      return result;
+   }
+   template <unsigned MinBits2, unsigned MaxBits2, cpp_integer_type SignType2, cpp_int_check_type Checked2, class Allocator2>
+   int compare_imp(const cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2>& o, const mpl::true_&, const mpl::false_&)const
+   {
+      cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2> t(*this);
+      return t.compare(o);
+   }
+   template <unsigned MinBits2, unsigned MaxBits2, cpp_integer_type SignType2, cpp_int_check_type Checked2, class Allocator2>
+   int compare_imp(const cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2>& o, const mpl::false_&, const mpl::true_&)const
+   {
+      cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator> t(o);
+      return compare(t);
+   }
+   template <unsigned MinBits2, unsigned MaxBits2, cpp_integer_type SignType2, cpp_int_check_type Checked2, class Allocator2>
+   int compare_imp(const cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2>& o, const mpl::true_&, const mpl::true_&)const BOOST_NOEXCEPT
+   {
+      if(this->sign())
+      {
+         if(o.sign())
+         {
+            return *this->limbs() < *o.limbs() ? 1 : (*this->limbs() > *o.limbs() ? -1 : 0);
+         }
+         else
+            return -1;
+      }
+      else
+      {
+         if(o.sign())
+            return 1;
+         return *this->limbs() < *o.limbs() ? -1 : (*this->limbs() > *o.limbs() ? 1 : 0);
+      }
+   }
+   template <unsigned MinBits2, unsigned MaxBits2, cpp_integer_type SignType2, cpp_int_check_type Checked2, class Allocator2>
+   int compare(const cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2>& o)const BOOST_NOEXCEPT
+   {
+      typedef mpl::bool_<is_trivial_cpp_int<cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator> >::value> t1;
+      typedef mpl::bool_<is_trivial_cpp_int<cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2> >::value> t2;
+      return compare_imp(o, t1(), t2());
+   }
+   template <unsigned MinBits2, unsigned MaxBits2, cpp_integer_type SignType2, cpp_int_check_type Checked2, class Allocator2>
+   int compare_unsigned(const cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2>& o)const BOOST_NOEXCEPT
+   {
+      if(this->size() != o.size())
+      {
+         return this->size() > o.size() ? 1 : -1;
+      }
+      typename base_type::const_limb_pointer pa = this->limbs();
+      typename base_type::const_limb_pointer pb = o.limbs();
+      for(int i = this->size() - 1; i >= 0; --i)
+      {
+         if(pa[i] != pb[i])
+            return pa[i] > pb[i] ? 1 : -1;
+      }
+      return 0;
+   }
+   template <class Arithmetic>
+   BOOST_MP_FORCEINLINE typename boost::enable_if<is_arithmetic<Arithmetic>, int>::type compare(Arithmetic i)const
+   {
+      // braindead version:
+      cpp_int_backend t;
+      t = i;
+      return compare(t);
+   }
+};
+
+} // namespace backends
+
+namespace default_ops{
+
+template <class Backend>
+struct double_precision_type;
+
+template <unsigned MinBits, unsigned MaxBits, cpp_integer_type SignType, cpp_int_check_type Checked, class Allocator>
+struct double_precision_type<backends::cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator> >
+{
+   typedef typename mpl::if_c<
+      backends::is_fixed_precision<backends::cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator> >::value,
+      backends::cpp_int_backend<
+         (is_void<Allocator>::value ?
+            2 * backends::max_precision<backends::cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator> >::value
+            : MinBits),
+         2 * backends::max_precision<backends::cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator> >::value,
+         SignType,
+         Checked,
+         Allocator>,
+      backends::cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator>
+   >::type type;
+};
+
+
+}
+
+template <unsigned MinBits, unsigned MaxBits, cpp_integer_type SignType, cpp_int_check_type Checked>
+struct expression_template_default<backends::cpp_int_backend<MinBits, MaxBits, SignType, Checked, void> >
+{
+   static const expression_template_option value = et_off;
+};
+
+using boost::multiprecision::backends::cpp_int_backend;
+
+template <unsigned MinBits, unsigned MaxBits, cpp_integer_type SignType, cpp_int_check_type Checked, class Allocator>
+struct number_category<cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator> > : public mpl::int_<number_kind_integer>{};
+
+typedef number<cpp_int_backend<> >                   cpp_int;
+typedef rational_adaptor<cpp_int_backend<> >         cpp_rational_backend;
+typedef number<cpp_rational_backend>                 cpp_rational;
+
+// Fixed precision unsigned types:
+typedef number<cpp_int_backend<128, 128, unsigned_magnitude, unchecked, void> >   uint128_t;
+typedef number<cpp_int_backend<256, 256, unsigned_magnitude, unchecked, void> >   uint256_t;
+typedef number<cpp_int_backend<512, 512, unsigned_magnitude, unchecked, void> >   uint512_t;
+typedef number<cpp_int_backend<1024, 1024, unsigned_magnitude, unchecked, void> > uint1024_t;
+
+// Fixed precision signed types:
+typedef number<cpp_int_backend<128, 128, signed_magnitude, unchecked, void> >    int128_t;
+typedef number<cpp_int_backend<256, 256, signed_magnitude, unchecked, void> >    int256_t;
+typedef number<cpp_int_backend<512, 512, signed_magnitude, unchecked, void> >    int512_t;
+typedef number<cpp_int_backend<1024, 1024, signed_magnitude, unchecked, void> >  int1024_t;
+
+// Over again, but with checking enabled this time:
+typedef number<cpp_int_backend<0, 0, signed_magnitude, checked> >  checked_cpp_int;
+typedef rational_adaptor<cpp_int_backend<0, 0, signed_magnitude, checked> >  checked_cpp_rational_backend;
+typedef number<cpp_rational_backend>                 checked_cpp_rational;
+// Fixed precision unsigned types:
+typedef number<cpp_int_backend<128, 128, unsigned_magnitude, checked, void> >   checked_uint128_t;
+typedef number<cpp_int_backend<256, 256, unsigned_magnitude, checked, void> >   checked_uint256_t;
+typedef number<cpp_int_backend<512, 512, unsigned_magnitude, checked, void> >   checked_uint512_t;
+typedef number<cpp_int_backend<1024, 1024, unsigned_magnitude, checked, void> > checked_uint1024_t;
+
+// Fixed precision signed types:
+typedef number<cpp_int_backend<128, 128, signed_magnitude, checked, void> >    checked_int128_t;
+typedef number<cpp_int_backend<256, 256, signed_magnitude, checked, void> >    checked_int256_t;
+typedef number<cpp_int_backend<512, 512, signed_magnitude, checked, void> >    checked_int512_t;
+typedef number<cpp_int_backend<1024, 1024, signed_magnitude, checked, void> >  checked_int1024_t;
+
+#ifdef BOOST_NO_SFINAE_EXPR
+
+namespace detail{
+
+template<unsigned MinBits, unsigned MaxBits, cpp_integer_type SignType, cpp_int_check_type Checked, class Allocator, unsigned MinBits2, unsigned MaxBits2, cpp_integer_type SignType2, cpp_int_check_type Checked2, class Allocator2>
+struct is_explicitly_convertible<cpp_int_backend<MinBits, MaxBits, SignType, Checked, Allocator>, cpp_int_backend<MinBits2, MaxBits2, SignType2, Checked2, Allocator2> > : public mpl::true_ {};
+
+}
+#endif
+
+}} // namespaces
+
+//
+// Last of all we include the implementations of all the eval_* non member functions:
+//
+#include <boost/multiprecision/cpp_int/comparison.hpp>
+#include <boost/multiprecision/cpp_int/add.hpp>
+#include <boost/multiprecision/cpp_int/multiply.hpp>
+#include <boost/multiprecision/cpp_int/divide.hpp>
+#include <boost/multiprecision/cpp_int/bitwise.hpp>
+#include <boost/multiprecision/cpp_int/misc.hpp>
+#include <boost/multiprecision/cpp_int/limits.hpp>
+#ifdef BOOST_MP_USER_DEFINED_LITERALS
+#include <boost/multiprecision/cpp_int/literals.hpp>
+#endif
+#include <boost/multiprecision/cpp_int/serialize.hpp>
+
+#endif