object
<iostream>
std::cerr
Standard output stream for errors
Object of class ostream that represents the standard error stream oriented to narrow characters (of type char). It corresponds to the C stream stderr.
The standard error stream is a destination of characters determined by the environment. This destination may be shared by more than one standard object (such as cout or clog).
As an object of class ostream, characters can be written to it either as formatted data using the insertion operator (operator<<) or as unformatted data, using member functions such as write.
The object is declared in header <iostream> with external linkage and static duration: it lasts the entire duration of the program.
In terms of
static initialization order,
cerr is guaranteed to be properly constructed and initialized no later than the first time an object of type
ios_base::Init is constructed.
cerr is not
tied to any other output stream (see
ios::tie).
In terms of
static initialization order,
cerr is guaranteed to be properly constructed and initialized no later than the first time an object of type
ios_base::Init is constructed, with the inclusion of
<iostream> counting as at least one initialization of such objects with
static duration.
cerr is
tied to the standard output stream
cout (see
ios::tie), which indicates that
cout's buffer is
flushed (see
ostream::flush) before each i/o operation performed on
cerr.
By default, cerr is synchronized with stderr (see ios_base::sync_with_stdio).
A program should not mix output operations on cerr with output operations on wcerr or wclog (or with other wide-oriented output operations on stderr): Once an output operation has been performed on either, the standard error stream acquires an orientation (either narrow or wide) that can only be safely changed by calling freopen on stderr.
For more information on the operations supported by cerr, see the reference for its type: ostream.
See also
- ostream
- Output Stream (class)
- cout
- Standard output stream (object)
- clog
- Standard output stream for logging (object)
- cin
- Standard input stream (object)
- wcerr
- Standard output stream for errors (wide-oriented) (object)