cerr
The object cerr controls output to a stream buffer associated with the object stderr, declared in <cstdio>.
Syntax
extern ostream cerr;
Return Value
An ostream object.
Remarks
The object controls unbuffered insertions to the standard error output as a byte stream. Once the object is constructed, the expression cerr.flags & unitbuf is nonzero, and cerr.tie() == &cout.
Example
// iostream_cerr.cpp
// compile with: /EHsc
#include <iostream>
#include <fstream>
using namespace std;
void TestWide( )
{
int i = 0;
wcout << L"Enter a number: ";
wcin >> i;
wcerr << L"test for wcerr" << endl;
wclog << L"test for wclog" << endl;
}
int main( )
{
int i = 0;
cout << "Enter a number: ";
cin >> i;
cerr << "test for cerr" << endl;
clog << "test for clog" << endl;
TestWide( );
}
Input
3
1
Sample Output
Enter a number: 3
test for cerr
test for clog
Enter a number: 1
test for wcerr
test for wclog
Requirements
Header: <iostream>
Namespace: std