Knowledge Base

BUG: ios::internal Adds No Fill Characters for int and long

Article ID: 123161

Article Last Modified on 7/5/2005

Microsoft Visual C++ 1.5 Professional Edition
Microsoft Visual C++ 1.51
Microsoft Visual C++ 5.0 Enterprise Edition
Microsoft Visual C++ 5.0 Professional Edition
Microsoft Visual C++ 1.0 Professional Edition
Microsoft Visual C++ 2.0 Professional Edition
Microsoft Visual C++ 2.1
Microsoft Visual C++ 4.0 Standard Edition
Microsoft Visual C++ 4.1 Subscription
Microsoft Visual C++ 4.2 Professional Edition

This article was previously published under Q123161

SYMPTOMS

Using member function ios::flags() with flag ios::internal fails to add fill characters after the leading sign but before the value. This only occurs for negative integers or negative long integers. For other data types and positive integers or positive long integers, the flag works correctly.

The following is output from the sample program given under "MORE INFORMATION":

   --- Output Starts ---

+          1234      // Correct, positive integer with space between
                        + and 1234.

+          1234      // Correct, positive long integer.
+      1234.000      // Correct, positive float.
+      1234.000      // Correct, positive double.
          -1234      // Incorrect, negative integer with no space
                        between - and 1234.
          -1234      // Incorrect, negative long integer.
-     1.23e+003      // Correct, negative float in scientific notation.
-     1.23e+003      // Correct, negative double.

   --- Output Ends ---

RESOLUTION

Cast the integer or long integer values to float or double values, and use manipulator setprecision(0) and ios flag ios::fixed. See the sample code in the "More Information" section of this article.

STATUS

Microsoft has confirmed that this is a bug in the Microsoft products that are listed at the beginning of this article.

MORE INFORMATION

Sample Code to Reproduce Problem

/* Compile options needed: none
*/ 

#include        <IOSTREAM.H>
#include        <IOMANIP.H>

#pragma         warning( disable : 4270 )
#define         WIDTH   20

void main( void )
{
  int i = 1234;

  cout.flags( ios::showpos | ios::internal );
  cout << setw(WIDTH) << (int) i << endl;
  cout << setw(WIDTH) << (long) i << endl;

  cout.precision(3);
  cout.flags( ios::showpos | ios::internal | ios::fixed );
  cout << setw(WIDTH) << (float) i << endl;
  cout << setw(WIDTH) << (double) i << endl;

  cout << setw(WIDTH) << (int)-i << endl;  // Problem
  cout << setw(WIDTH) << (long)-i << endl; // Problem

  // The following two lines show how to work around the problem.
  // cout << setprecision(0) << setw(WIDTH) <<  (float)-i << endl;
  // cout << setprecision(0) << setw(WIDTH) <<  (float)-i << endl;

  cout.precision(3);
  cout.flags( ios::showpos | ios::internal | ios::scientific );
  cout << setw(WIDTH) << (float)-i << endl;
  cout << setw(WIDTH) << (double)-i << endl;
}

Additional query words: kbVC400bug buglist1.50 buglist1.00 buglist2.00

Keywords: kbbug kbcodegen KB123161