text: //  Copyright John Maddock 2007.
  //  Use, modification and distribution are subject to 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)
  
  #ifndef BOOST_MATH_TRUNC_HPP
  #define BOOST_MATH_TRUNC_HPP
  
  #ifdef _MSC_VER
  #pragma once
  #endif
  
  #include <boost/math/special_functions/math_fwd.hpp>
  #include <boost/math/tools/config.hpp>
  #include <boost/math/policies/error_handling.hpp>
  #include <boost/math/special_functions/fpclassify.hpp>
  #include <boost/type_traits/is_constructible.hpp>
  #include <boost/core/enable_if.hpp>
  
  namespace boost{ namespace math{ namespace detail{
  
  template <class T, class Policy>
  inline typename tools::promote_args<T>::type trunc(const T& v, const Policy& pol, const boost::false_type&)
  {
     BOOST_MATH_STD_USING
     typedef typename tools::promote_args<T>::type result_type;
     if(!(boost::math::isfinite)(v))
        return policies::raise_rounding_error("boost::math::trunc<%1%>(%1%)", 0, static_cast<result_type>(v), static_cast<result_type>(v), pol);
     return (v >= 0) ? static_cast<result_type>(floor(v)) : static_cast<result_type>(ceil(v));
  }
  
  template <class T, class Policy>
  inline typename tools::promote_args<T>::type trunc(const T& v, const Policy&, const boost::true_type&)
  {
     return v;
  }
  
  }
  
  template <class T, class Policy>
  inline typename tools::promote_args<T>::type trunc(const T& v, const Policy& pol)
  {
     return detail::trunc(v, pol, boost::integral_constant<bool, detail::is_integer_for_rounding<T>::value>());
  }
  template <class T>
  inline typename tools::promote_args<T>::type trunc(const T& v)
  {
     return trunc(v, policies::policy<>());
  }
  //
  // The following functions will not compile unless T has an
  // implicit conversion to the integer types.  For user-defined
  // number types this will likely not be the case.  In that case
  // these functions should either be specialized for the UDT in
  // question, or else overloads should be placed in the same
  // namespace as the UDT: these will then be found via argument
  // dependent lookup.  See our concept archetypes for examples.
  //
  template <class T, class Policy>
  inline int itrunc(const T& v, const Policy& pol)
  {
     BOOST_MATH_STD_USING
     typedef typename tools::promote_args<T>::type result_type;
     result_type r = boost::math::trunc(v, pol);
     if((r > (std::numeric_limits<int>::max)()) || (r < (std::numeric_limits<int>::min)()))
        return static_cast<int>(policies::raise_rounding_error("boost::math::itrunc<%1%>(%1%)", 0, static_cast<result_type>(v), 0, pol));
     return static_cast<int>(r);
  }
  template <class T>
  inline int itrunc(const T& v)
  {
     return itrunc(v, policies::policy<>());
  }
  
  template <class T, class Policy>
  inline long ltrunc(const T& v, const Policy& pol)
  {
     BOOST_MATH_STD_USING
     typedef typename tools::promote_args<T>::type result_type;
     result_type r = boost::math::trunc(v, pol);
     if((r > (std::numeric_limits<long>::max)()) || (r < (std::numeric_limits<long>::min)()))
        return static_cast<long>(policies::raise_rounding_error("boost::math::ltrunc<%1%>(%1%)", 0, static_cast<result_type>(v), 0L, pol));
     return static_cast<long>(r);
  }
  template <class T>
  inline long ltrunc(const T& v)
  {
     return ltrunc(v, policies::policy<>());
  }
  
  #ifdef BOOST_HAS_LONG_LONG
  
  template <class T, class Policy>
  inline boost::long_long_type lltrunc(const T& v, const Policy& pol)
  {
     BOOST_MATH_STD_USING
     typedef typename tools::promote_args<T>::type result_type;
     result_type r = boost::math::trunc(v, pol);
     if((r > (std::numeric_limits<boost::long_long_type>::max)()) || (r < (std::numeric_limits<boost::long_long_type>::min)()))
        return static_cast<boost::long_long_type>(policies::raise_rounding_error("boost::math::lltrunc<%1%>(%1%)", 0, v, static_cast<boost::long_long_type>(0), pol));
     return static_cast<boost::long_long_type>(r);
  }
  template <class T>
  inline boost::long_long_type lltrunc(const T& v)
  {
     return lltrunc(v, policies::policy<>());
  }
  
  #endif
  
  template <class T, class Policy>
  inline typename boost::enable_if_c<boost::is_constructible<int, T>::value, int>::type
     iconvert(const T& v, const Policy&) 
  {
     return static_cast<int>(v);
  }
  
  template <class T, class Policy>
  inline typename boost::disable_if_c<boost::is_constructible<int, T>::value, int>::type
     iconvert(const T& v, const Policy& pol) 
  {
     using boost::math::itrunc;
     return itrunc(v, pol);
  }
  
  template <class T, class Policy>
  inline typename boost::enable_if_c<boost::is_constructible<long, T>::value, long>::type
     lconvert(const T& v, const Policy&) 
  {
     return static_cast<long>(v);
  }
  
  template <class T, class Policy>
  inline typename boost::disable_if_c<boost::is_constructible<long, T>::value, long>::type
     lconvert(const T& v, const Policy& pol) 
  {
     using boost::math::ltrunc;
     return ltrunc(v, pol);
  }
  
  #ifdef BOOST_HAS_LONG_LONG
  
  template <class T, class Policy>
  inline typename boost::enable_if_c<boost::is_constructible<boost::long_long_type, T>::value, boost::long_long_type>::type
     llconvertert(const T& v, const Policy&) 
  {
     return static_cast<boost::long_long_type>(v);
  }
  
  template <class T, class Policy>
  inline typename boost::disable_if_c<boost::is_constructible<boost::long_long_type, T>::value, boost::long_long_type>::type
     llconvertert(const T& v, const Policy& pol) 
  {
     using boost::math::lltrunc;
     return lltrunc(v, pol);
  }
  
  #endif
  
  }} // namespaces
  
  #endif // BOOST_MATH_TRUNC_HPP
  