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

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< cpp‎ | io‎ | manip
Revision as of 07:35, 16 June 2013 by SuperBoi45 (Talk | contribs)

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

Modifies the default positioning of the fill characters. left and right apply to any 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)

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.

Contents

[edit] Parameters

str - reference to I/O stream

[edit] Return value

str (reference to the stream after manipulation)

[edit] Example

#include <iostream>
#include <iomanip>
#include <locale>
 
int main()
{
    std::cout.imbue(std::locale("en_US.utf8"));
    std::cout << "Left fill:\n" << std::left << 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 << "Internal fill:\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 fill:\n" << std::right
              << std::setw(12) << -1.23  << '\n'
              << std::setw(12) << 42 << '\n'
              << std::setw(12) << std::put_money(123, true) << '\n';
}

Output:

Left fill:
-1.23*******
0x2a********
USD *1.23***
 
Internal fill:
-*******1.23
0x********2a
USD ****1.23
 
Right fill:
*******-1.23
********0x2a
***USD *1.23

[edit] See also

changes the width of the next input/output field
(function) [edit]
changes the fill character
(function template) [edit]