text: #pragma once
  #include <string>
  #include <vector>
  #include "StringOP.h"
  
  class CMBBlock;
  
  class CEnvExchange
  {
  public:
  	CEnvExchange(void);
  	~CEnvExchange(void);
  	CEnvExchange(const CEnvExchange &B);
  	CEnvExchange(string _model);
      CEnvExchange& operator=(const CEnvExchange &BB);
  	CStringOP expression;
  	string model;
  	string constituent;
  	string phase;
  	string solid;
  	vector<double> parameters;
      double calculate(CMBBlock *Block);
      double calculate_star(CMBBlock *Block);
      void set_val(string S, double val);
      void set_val(int i, double val);
  	string name;
  };
  
  