NAME¶

std::left,std::right,std::internal - std::left,std::right,std::internal

Synopsis¶

Defined in header <ios>
std::ios_base& left( std::ios_base& str ); (1)
std::ios_base& right( std::ios_base& str ); (2)
std::ios_base& internal( std::ios_base& str ); (3)

Modifies the positioning of the fill characters in an output stream. left and right
apply to any type being output, internal applies to integer, floating-point, and
monetary output. Has no effect on input.

1) sets the adjustfield of the stream str to left as if by calling
str.setf(std::ios_base::left, std::ios_base::adjustfield)

2) sets the adjustfield of the stream str to right as if by calling
str.setf(std::ios_base::right, std::ios_base::adjustfield)

3) sets the adjustfield of the stream str to internal as if by calling
str.setf(std::ios_base::internal, std::ios_base::adjustfield)

The initial default for standard streams is equivalent to right.

This is an I/O manipulator. It may be called with an expression such as out <<
std::left for any out of type std::basic_ostream or with an expression such as in >>
std::left for any in of type std::basic_istream.

Parameters¶

str - reference to I/O stream

Return value¶

str (reference to the stream after manipulation)

Example¶

// Run this code

#include <iostream>
#include <iomanip>
#include <locale>

int main()
{
std::cout.imbue(std::locale("en_US.utf8"));

std::cout << "Default positioning:\n" << std::setfill('*')
<< std::setw(12) << -1.23 << '\n'
<< std::setw(12) << std::hex << std::showbase << 42 << '\n'
<< std::setw(12) << std::put_money(123, true) << "\n\n";

std::cout << "Left positioning:\n" << std::left
<< std::setw(12) << -1.23 << '\n'
<< std::setw(12) << 42 << '\n'
<< std::setw(12) << std::put_money(123, true) << "\n\n";

std::cout << "Internal positioning:\n" << std::internal
<< std::setw(12) << -1.23 << '\n'
<< std::setw(12) << 42 << '\n'
<< std::setw(12) << std::put_money(123, true) << "\n\n";

std::cout << "Right positioning:\n" << std::right
<< std::setw(12) << -1.23 << '\n'
<< std::setw(12) << 42 << '\n'
<< std::setw(12) << std::put_money(123, true) << '\n';
}

Output:¶

Default positioning:
*******-1.23
********0x2a
***USD *1.23

Left positioning:
-1.23*******
0x2a********
USD *1.23***

Internal positioning:
-*******1.23
0x********2a
USD ****1.23

Right positioning:
*******-1.23
********0x2a
***USD *1.23

See also¶

setw changes the width of the next input/output field
(function)
setfill changes the fill character
(function template)
showbase controls whether prefix is used to indicate numeric base
noshowbase (function)