list2103.cpp

teach yourself C++ in 21 days 第五版

// Listing 21.3 ASSERTS
#define DEBUG
#include <iostream>
using namespace std;
  
#ifndef DEBUG
   #define ASSERT(x)
#else
   #define ASSERT(x) \
         if (! (x)) \
         { \
            cout << "ERROR!! Assert " << #x << " failed" << endl; \
            cout << " on line " << __LINE__  << endl; \
            cout << " in file " << __FILE__ << endl;  \
         }
#endif
  
int main()
{
   int x = 5;
   cout << "First assert: " << endl;
   ASSERT(x==5);
   cout << "\nSecond assert: " << endl;
   ASSERT(x != 5);
   cout << "\nDone." << endl;
   return 0;
}