C++的流复位操作

#include
#include
using namespace std;

#include
#include

/**

回复流状态之后要清空缓冲区，不然还是读取你最近一次输入的错误数据，在cin >> n之前加入如下代码：

C/C++ code

if(!cin.good()) { cin.clear(); cin.sync();//清空缓冲区 }

*/

 

 

    
int main()
{
    int ival;
    while(cin>>ival,!cin.eof()) {
       if (cin.bad())
          throw runtime_error("io stream corrupted");
       if(cin.fail()) {
          cerr<<"bwd data,try again\n";
          //cin.clear(iostream::failbit);
          cin.clear();   //流复位
          cin.sync();    //清空缓冲区
         
          continue;
       
       }
    }
    cin.clear();

    cout<<"输入一个数:";
    int a;
    cin>>a;
    cout<    
   getchar();
   getchar();
   
}

 

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练习1

         编写一个函数，其唯一的形参和返回值都是istream&类型。该函数一直读取流直到文件结束符为止，还应将读取的内容输出到标准输出中。最后，重设流使其有效，并返回该流。

#include

#include

using namespace std;

 

#include

#include

 

istream& get(istream &in)

{

         int ival;

         while(in>>ival,!in.eof())  {

            if(in.bad() )

               throw runtime_error("io stream error\n");

            if (in.fail()) {

               cerr<<"bad data, try again\n";

               in.clear();

               in.ignor(200,' ');

               continue;

            }

            cout<

         }

         in.clear();

         return in;

}

  

  

    

int main()

{

   get(cin); 

   getchar();

   getchar();

   

}