visual studio 2008: fstream bug?

The following C++ source code always successfully write in GCC3.4.4, and VC++ 6.0,

but failed in VS2008. The file 0000.txt is already in thedisk.

(1) OUTPUT in GCC 3.4.4 and VC 6.0:

     READ=0 WRITE=0

     READ=41  WRITE=41

     READ=27  WRITE=27

     READ=91  WRITE=91  

    

(2) Output in VS2008:

     READ=0  WRITE=0

    READ=45  WRITE=45

    READ=29  WRITE=29

    READ=-1  WRITE=-1

Looks like VS2008 always failed to write information to fileafter calling

   myFile<<"^^^^^^^^^^^^^^^^^^^------------------------------------^^^^^^^^"; 

What a shit!

=========================================================================================

#include

#include

using namespace std;

#define DBG()   cout<<"READ="<<myFile.tellg()<<" WRITE="<<myFile.tellp()<<endl; 

int main() 

{ 

fstream myFile( "E:\\0000.txt"); // default mode for fstreamis ios::in | ios::out 

myFile.seekp(0,ios::beg); // put pointer

DBG();         

myFile<<"Hel--\nWorld\n============SEU\nWelcome!\n!!!!"; 

DBG();

myFile.seekg(0,ios::beg); // if no this,myFile>>s will fail, andbreak! 

 

 chars[100],s1[100],s2[100]; 

myFile>>s>>s1>>s2; 

DBG();

// 这时 DBG()宏打印出来的读写位置都是29，文件长度是45，理论上应该可以写

// 而下面的seekp()移动到的位置就是当前位置，我发现如果没有这句话，VS2008就是写不进去！

 

//myFile.seekp(29,ios::beg); 

myFile<<"^^^^^^^^^^^^^^^^^^^------------------------------------^^^^^^^^"; 

DBG();

myFile.close(); 

return 0; 

}