text: //------------------------------------------------------------------------------
  /*
      This file is part of rippled: https://github.com/ripple/rippled
      Copyright (c) 2012, 2013 Ripple Labs Inc.
  
      Permission to use, copy, modify, and/or distribute this software for any
      purpose  with  or without fee is hereby granted, provided that the above
      copyright notice and this permission notice appear in all copies.
  
      THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
      WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
      MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
      ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
      WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
      ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
      OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
  //==============================================================================
  
  #ifndef RIPPLE_PROTOCOL_AMOUNTCONVERSION_H_INCLUDED
  #define RIPPLE_PROTOCOL_AMOUNTCONVERSION_H_INCLUDED
  
  #include <ripple/protocol/IOUAmount.h>
  #include <ripple/protocol/XRPAmount.h>
  #include <ripple/protocol/STAmount.h>
  
  namespace ripple {
  
  inline
  STAmount
  toSTAmount (IOUAmount const& iou, Issue const& iss)
  {
      bool const isNeg = iou.signum() < 0;
      std::uint64_t const umant = isNeg ? - iou.mantissa () : iou.mantissa ();
      return STAmount (iss, umant, iou.exponent (), /*native*/ false, isNeg,
                       STAmount::unchecked ());
  }
  
  inline
  STAmount
  toSTAmount (IOUAmount const& iou)
  {
      return toSTAmount (iou, noIssue ());
  }
  
  inline
  STAmount
  toSTAmount (XRPAmount const& xrp)
  {
      bool const isNeg = xrp.signum() < 0;
      std::uint64_t const umant = isNeg ? - xrp.drops () : xrp.drops ();
      return STAmount (umant, isNeg);
  }
  
  inline
  STAmount
  toSTAmount (XRPAmount const& xrp, Issue const& iss)
  {
      assert (isXRP(iss.account) && isXRP(iss.currency));
      return toSTAmount (xrp);
  }
  
  template <class T>
  T
  toAmount (STAmount const& amt)
  {
      static_assert(sizeof(T) == -1, "Must use specialized function");
      return T(0);
  }
  
  template <>
  inline
  STAmount
  toAmount<STAmount> (STAmount const& amt)
  {
      return amt;
  }
  
  template <>
  inline
  IOUAmount
  toAmount<IOUAmount> (STAmount const& amt)
  {
      assert (amt.mantissa () < std::numeric_limits<std::int64_t>::max ());
      bool const isNeg = amt.negative ();
      std::int64_t const sMant =
              isNeg ? - std::int64_t (amt.mantissa ()) : amt.mantissa ();
  
      assert (! isXRP (amt));
      return IOUAmount (sMant, amt.exponent ());
  }
  
  template <>
  inline
  XRPAmount
  toAmount<XRPAmount> (STAmount const& amt)
  {
      assert (amt.mantissa () < std::numeric_limits<std::int64_t>::max ());
      bool const isNeg = amt.negative ();
      std::int64_t const sMant =
              isNeg ? - std::int64_t (amt.mantissa ()) : amt.mantissa ();
  
      assert (isXRP (amt));
      return XRPAmount (sMant);
  }
  
  
  }
  
  #endif
  