std::showbase, std::noshowbase

Header: <ios>

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

# Declarations

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

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

# Parameters

# Return value

str (reference to the stream after manipulation).

# Notes

As specifed in std::num_put::put, the showbase flag in integer output acts like the # format specifier in std::printf, which means the numeric base prefix is not added when outputting the value zero.

# Example

#include <iomanip>
#include <iostream>
#include <locale>
#include <sstream>
 
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("3.14") >> std::showbase >> std::get_money(val);
    std::cout << "With showbase, parsing 3.14 as money gives " << val << '\n';
    std::istringstream("3.14") >> std::noshowbase >> std::get_money(val);
    std::cout << "Without showbase, parsing 3.14 as money gives " << val << '\n';
}

# See also