std::left, std::right, std::
From cppreference.com
Defined in header <ios>
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||
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std::ios_base
& left(
std::ios_base
& str )
;
|
(1) | |
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std::ios_base
& right(
std::ios_base
& str )
;
|
(2) | |
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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
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 <iomanip> #include <iostream> #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
| changes the width of the next input/output field (function) |
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| changes the fill character (function template) |
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| controls whether prefix is used to indicate numeric base (function) |