text: // Copyright (c) 2009-2010 Satoshi Nakamoto
  // Copyright (c) 2009-2014 The Bitcoin developers
  // Copyright (c) 2017-2018 The PIVX developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #ifndef BITCOIN_AMOUNT_H
  #define BITCOIN_AMOUNT_H
  
  #include "serialize.h"
  
  #include <stdlib.h>
  #include <string>
  
  /** Amount in satoshis (Can be negative) */
  typedef int64_t CAmount;
  
  static const CAmount COIN = 100000000;
  static const CAmount CENT = 1000000;
  
  extern const std::string CURRENCY_UNIT;
  
  /** No amount larger than this (in satoshi) is valid.
   *
   * Note that this constant is *not* the total money supply, which in Bitcoin
   * currently happens to be less than 21,000,000 BTC for various reasons, but
   * rather a sanity check. As this sanity check is used by consensus-critical
   * validation code, the exact value of the MAX_MONEY constant is consensus
   * critical; in unusual circumstances like a(nother) overflow bug that allowed
   * for the creation of coins out of thin air modification could lead to a fork.
   * */
  static const CAmount MAX_MONEY = 21000000 * COIN;
  inline bool MoneyRange(const CAmount& nValue) { return (nValue >= 0 && nValue <= MAX_MONEY); }
  
  /**
   * Fee rate in satoshis per kilobyte: CAmount / kB
   */
  class CFeeRate
  {
  private:
      CAmount nSatoshisPerK; // unit is satoshis-per-1,000-bytes
  public:
      CFeeRate() : nSatoshisPerK(0) {}
      explicit CFeeRate(const CAmount& _nSatoshisPerK) : nSatoshisPerK(_nSatoshisPerK) {}
      CFeeRate(const CAmount& nFeePaid, size_t nSize);
      CFeeRate(const CFeeRate& other) { nSatoshisPerK = other.nSatoshisPerK; }
  
      CAmount GetFee(size_t size) const;                  // unit returned is satoshis
      CAmount GetFeePerK() const { return GetFee(1000); } // satoshis-per-1000-bytes
  
      friend bool operator<(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK < b.nSatoshisPerK; }
      friend bool operator>(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK > b.nSatoshisPerK; }
      friend bool operator==(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK == b.nSatoshisPerK; }
      friend bool operator<=(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK <= b.nSatoshisPerK; }
      friend bool operator>=(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK >= b.nSatoshisPerK; }
      std::string ToString() const;
  
      ADD_SERIALIZE_METHODS;
  
      template <typename Stream, typename Operation>
      inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion)
      {
          READWRITE(nSatoshisPerK);
      }
  };
  
  #endif //  BITCOIN_AMOUNT_H
  