<ostream> operators
The latest version of this topic can be found at <ostream> operators.
These are the global template operator functions defined in <ostream>. For member operator functions, see the basic_ostream Class documentation.
operator<<
Writes various types to the stream.
template <class _Elem, class _Tr>
basic_ostream<_Elem, _Tr>& operator<<(
basic_ostream<_Elem, _Tr>& _Ostr,
const Elem* str);
template <class _Elem, class _Tr>
basic_ostream<_Elem, _Tr>& operator<<(
basic_ostream<_Elem, _Tr>& _Ostr,
Elem _Ch);
template <class _Elem, class _Tr>
basic_ostream<_Elem, _Tr>& operator<<(
basic_ostream<_Elem, _Tr>& _Ostr,
const char* str);
template <class _Elem, class _Tr>
basic_ostream<_Elem, _Tr>& operator<<(
basic_ostream<_Elem, _Tr>& _Ostr,
char _Ch);
template <class _Tr>
basic_ostream<char, _Tr>& operator<<(
basic_ostream<char, _Tr>& _Ostr,
const char* str);
template <class _Tr>
basic_ostream<char, _Tr>& operator<<(
basic_ostream<char, _Tr>& _ostr,
char _Ch);
template <class _Tr>
basic_ostream<char, _Tr>& operator<<(
basic_ostream<char, _Tr>& _Ostr,
const signed char* str);
template <class _Tr>
basic_ostream<char, _Tr>& operator<<(
basic_ostream<char, _Tr>& _Ostr,
signed char _Ch);
template <class _Tr>
basic_ostream<char, _Tr>& operator<<(
basic_ostream<char, _Tr>& _Ostr,
const unsigned char* str);
template <class _Tr>
basic_ostream<char, _Tr>& operator<<(
basic_ostream<char, _Tr>& _Ostr,
unsigned char _Ch);
template <class _Elem, class _Tr, class T>
basic_ostream <_Elem, _Tr>& operator<<(
basic_ostream<_Elem, _Tr>&& _Ostr,
Ty val);
Parameters
_Ch
A character.
_Elem
The element type.
_Ostr
A basic_ostream object.
str
A character string.
_Tr
Character traits.
val
The type
Return Value
The stream.
Remarks
The basic_ostream class also defines several insertion operators. For more information, see basic_ostream::operator<<.
The template function
template <class _Elem, class _Tr>
basic_ostream<Elem, _Tr>& operator<<(
basic_ostream<Elem, _Tr>& _ostr,
const Elem *str);
determines the length N = traits_type::length( str) of the sequence beginning at str, and inserts the sequence. If N < _Ostr.width, then the function also inserts a repetition of _Ostr.``width - N fill characters. The repetition precedes the sequence if ( _Ostr. flags & adjustfield != left. Otherwise, the repetition follows the sequence. The function returns _Ostr.
The template function
template <class _Elem, class _Tr>
basic_ostream<Elem, _Tr>& operator<<(
basic_ostream<Elem, _Tr>& _Ostr,
Elem _Ch);
inserts the element _Ch. If 1 < _Ostr.width, then the function also inserts a repetition of _Ostr.width - 1 fill characters. The repetition precedes the sequence if _Ostr.flags & adjustfield != left. Otherwise, the repetition follows the sequence. It returns _Ostr.
The template function
template <class _Elem, class _Tr>
basic_ostream<Elem, _Tr>& operator<<(
basic_ostream<Elem, _Tr>& _Ostr,
const char *str);
behaves the same as
template <class _Elem, class _Tr>
basic_ostream<Elem, _Tr>& operator<<(
basic_ostream<Elem, _Tr>& _Ostr,
const Elem *str);
except that each element _Ch of the sequence beginning at str is converted to an object of type Elem by calling _Ostr.put( _Ostr.widen( _Ch)).
The template function
template <class _Elem, class _Tr>
basic_ostream<Elem, _Tr>& operator<<(
basic_ostream<Elem, _Tr>& _Ostr,
char _Ch);
behaves the same as
template <class _Elem, class _Tr>
basic_ostream<Elem, _Tr>& operator<<(
basic_ostream<Elem, _Tr>& _Ostr,
Elem _Ch);
except that _Ch is converted to an object of type Elem by calling _Ostr.put( _Ostr.widen( _Ch)).
The template function
template <class _Tr>
basic_ostream<char, _Tr>& operator<<(
basic_ostream<char, _Tr>& _Ostr,
const char *str);
behaves the same as
template <class _Elem, class _Tr>
basic_ostream<Elem, _Tr>& operator<<(
basic_ostream<Elem, _Tr>& _Ostr,
const Elem *str);
(It does not have to widen the elements before inserting them.)
The template function
template <class _Tr>
basic_ostream<char, Tr>& operator<<(
basic_ostream<char, _Tr>& _Ostr,
char _Ch);
behaves the same as
template <class _Elem, class _Tr>
basic_ostream<Elem, _Tr>& operator<<(
basic_ostream<Elem, _Tr>& _Ostr,
Elem _Ch);
(It does not have to widen _Ch before inserting it.)
The template function
template <class _Tr>
basic_ostream<char, _Tr>& operator<<(
basic_ostream<char, _Tr>& _Ostr,
const signed char *str);
returns _Ostr << ( const char *) str.
The template function
template <class _Tr>
basic_ostream<char, _Tr>& operator<<(
basic_ostream<char, _Tr>& _Ostr,
signed char _Ch);
returns _Ostr << ( char) _Ch.
The template function:
template <class _Tr>
basic_ostream<char, _Tr>& operator<<(
basic_ostream<char, _Tr>& _Ostr,
const unsigned char *str);
returns _Ostr << ( const char *) str.
The template function:
template <class _Tr>
basic_ostream<char, _Tr>& operator<<(
basic_ostream<char, _Tr>& _Ostr,
unsigned char _Ch);
returns _Ostr << ( char) _Ch.
The template function:
template <class _Elem, class _Tr, class T>
basic_ostream<_Elem, _Tr>& operator<<(
basic_ostream<char, _Tr>&& _Ostr,
T val);
returns _Ostr << val (and converts a RValue Reference to _Ostr to an lvalue in the process).
Example
See flush for an example using operator<<.