std::showbase, std::noshowbase

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Defined in header `<ios>`

std::ios_base& showbase( std::ios_base& str );	(1)

std::ios_base& noshowbase( std::ios_base& str );	(2)

1) enables the showbase flag in the stream str as if by calling str.setf(std::ios_base::showbase)

2) disables the showbase flag in the stream str as if by calling str.unsetf(std::ios_base::showbase)

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

#include <sstream>
#include <locale>
#include <iostream>
#include <iomanip>
int main()
{
    // showbase affects the output of octals and hexadecimals
    std::cout << std::hex
              << "showbase: " << std::showbase << 42 << '\n'
              << "noshowbase: " << std::noshowbase << 42 << '\n';
 
    // and both input and output of monetary values
    std::locale::global(std::locale("en_US.utf8"));
    long double val = 0;
    std::istringstream is("3.14");
    is >> std::showbase >> std::get_money(val);
    std::cout << "With showbase, parsing 3.14 as money gives " << val << '\n';
    is.seekg(0);
    is >> std::noshowbase >> std::get_money(val);
    std::cout << "Without showbase, parsing 3.14 as money gives " << val << '\n';
}

Output:

showbase: 0x2a
noshowbase: 2a
With showbase, parsing 3.14 as money gives 0
Without showbase, parsing 3.14 as money gives 314

[edit] See also


resetiosflags	clears the specified ios_base flags (function)

setiosflags	sets the specified ios_base flags (function)

Language
Standard library headers
Concepts
Utilities library
Strings library
Containers library
Algorithms library
Iterators library
Numerics library
Input/output library
Localizations library
Regular expressions library (C++11)
Atomic operations library (C++11)
Thread support library (C++11)

std::showbase, std::noshowbase

Contents

[edit] Parameters

[edit] Return value

[edit] Example

[edit] See also