ex2102.cpp

teach yourself C++ in 21 days 第五版

#include <iostream>
        
using namespace std;
#ifndef DEBUG
#define ASSERT(x)
#elif DEBUG == 1
#define ASSERT(x) \
             if (! (x)) \
              { \
       cout << "ERROR!! Assert " << #x << " failed" << endl; \
             }
#elif DEBUG == 2
#define ASSERT(x) \
             if (! (x) ) \
             { \
      cout << "ERROR!! Assert " << #x << " failed" << endl; \
      cout << " on line " << __LINE__  << endl; \
      cout << " in file " << __FILE__ << endl;  \
              }
#endif