## wcerr

    Pre-defined stream

- Summary
- Data Type and Member Function Indexes
- Synopsis
- Description
- Formatting
- Example
- See Also
- Standards Conformance

### Summary

Controls output to an unbuffered stream buffer associated with the object `stderr` declared in `<cstdio>`.

### Data Type and Member Function Indexes
(exclusive of constructors and destructors)

None

### Synopsis

    #include <iostream>
    extern wostream wcerr;
    wostream wcerr;

### Description

The object `wcerr` controls output to an unbuffered stream buffer associated with the object `stderr` declared in `<cstdio>`. By default the standard C and C++ streams are synchronized, but you can improve performance by using the `ios_base` member function `synch_with_stdio` to desynchronize them.

`wcerr` uses the locale `codecvt` facet to convert the wide characters it receives to the tiny characters it outputs to `stderr`.

### Formatting

The formatting is done through member functions or manipulators. See `cout`, `wcout`, or `basic_ostream` for details.

### Example

    //
    // wcerr example
    //
    #include<iostream>
    #include<fstream>

    void main ( )
    {
      using namespace std;

      // open the file "file_name.txt"
      // for reading
      wifstream in("file_name.txt");

      // output the all file to stdout
      if ( in )
        wcout << in.rdbuf();
      else
        // if the wifstream object is in a bad state
        // output an error message to stderr
        wcerr << L"Error while opening the file" << endl;
    }

### See Also

basic_ostream(3C++), iostream(3C++), basic_filebuf(3C++), cout(3C++), cin(3C++), cerr(3C++), clog(3C++), wcin(3C++), wcout(3C++), wclog(3C++), iomanip(3C++), ios_base(3C++), basic_ios(3C++)

Working Paper for Draft Proposed International Standard for Information Systems--Programming Language C++, Section 27.3.2

### Standards Conformance

ANSI X3J16/ISO WG21 Joint C++ Committee

Copyright (c) 1998, Rogue Wave Software, Inc.
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OEM Release, June 1998