如何重载cin到读取文件 [英] How to overload cin to read file

问题描述

可能重复：

操作输入文件流

C ++如何重载cin到读取文件

我尝试下面的操作符重载。

  struct自己
 {
 string myname; 
} 
 
 istream& operator>> （istream& stream，myself& mm）
 {
 cout< 输入我的名字：; 
 stream>> mm.myname; 
 return stream; 
} 
 
 int main（）
 {
 myself mm; 
 cin>> mm; 
 
 cout<< mm.myname; 
 
} 
  

及其工作，能够回应我实际类型。

现在我想继续使用

  cout< ; 输入要读取的文件名：; 
 
 //假设用户类型为myfile.txt 
 
 cin>> readFile; 
  

如何重载我的cin以使其读取文件。

考虑我的文件是

sometextdocument.txt，其中包含如

的数据

  Map2D，[3,2] 
 Dot3D，[25，-69，-33]，[-2，-41，58] 
 Map3D，[6，9 ，-50] 
 Map2D，[3,2] 
 Dot3D，[7，-12,3]，[9,13,68] 
 Map3D，[6,9,5] 
 Map2D，[3,2] 
 Dot3D，[70，-120，-3]，[-29,1,268] 
 Dot3D，[7,12,3] -9，13，68] 
 Map3D，[1,3,8] 
 Dot2D，[5,7]，[3,8] 
  pre> 
 
 
然后我wanna  cout< 读取的记录数：<数字<< endl;  
然后做一个返回流，我如何重载它工作作为cin读取文件
解决方案
 尝试这样：希望这将是有用的
  istream& ;> （istream& in，char * fname）{
 inFile.open（fname）; 
 char ch1; 
 while（inFile.get（ch1））{
 cout<< ch1; 
} 
} 
  
 

  
Possible Duplicate:

  Manipulate Input File Stream  
C++ How to overload cin to read file

I was trying the following with operator overload..
struct myself
{
string myname;
}

istream &operator>> (istream &stream, myself &mm)
{
cout << "Enter my name:";
stream >> mm.myname;
return stream;
}

int main()
{
myself mm;
cin >> mm;

cout << mm.myname;

}
and its work, able to echo out what i actually type.

Now i trying to proceed with 
cout << "Enter file name to read: ";

//assume user type myfile.txt

cin >> readFile;
How do i overload my cin to make it read file.

Consider my file is something like

sometextdocument.txt that contains data like
Map2D, [3, 2]
Dot3D, [25, -69, -33], [-2, -41, 58]
Map3D, [6, 9, -50]
Map2D, [3, 2]
Dot3D, [7, -12, 3], [9, 13, 68]
Map3D, [6, 9, 5]
Map2D, [3, 2]
Dot3D, [70, -120, -3], [-29, 1, 268]
Dot3D, [7, 12, 3], [-9, 13, 68]
Map3D, [1, 3, 8]
Dot2D, [5, 7], [3, 8]
And then i wanna cout << "Number of records read: " << number << endl;
then do a return stream, how do i overload it to work as cin read a file
解决方案
Try like this: hope it will be helpful 
istream &operator>> (istream &in, char* fname){ 
  inFile.open(fname);
  char ch1;
  while (inFile.get(ch1)) {
       cout<<ch1;
  }
}


                        
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