std::setiosflags(3)

💖 NAME 💖

std::setiosflags - std::setiosflags

okay bestie, you're on the std::setiosflags(3) page from the C++ Standard Libary (that's the header's spelling, iykyk 💀). This is the thing that sets format flags on a stream, and we're gonna get you through it without missing a single detail ✨💅

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✨ Synopsis ✨

Defined in header <iomanip> 🎀

/*unspecified*/ setiosflags( std::ios_base::fmtflags mask );

When used in an expression out << setiosflags(mask) or in the expression in >> setiosflags(mask), it sets all format flags of the stream out or in as specified by the mask ⭐

bestie, the return type is literally /*unspecified*/ — that's the whole vibe the page gives us 💀

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🌸 Parameters 🌸

• mask — bitmask of the flags to set. That's your little bundle of flag bits 🎀

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🦋 Return value 🦋

An object of unspecified type such that:

• if out is an object of type std::basic_ostream<CharT, Traits>, the expression out << setiosflags(mask)
  • has type std::basic_ostream<CharT, Traits>&
  • has value out
  • behaves as if it called f(out, mask)
• if in is an object of type std::basic_istream<CharT, Traits>, the expression in >> setiosflags(mask)
  • has type std::basic_istream<CharT, Traits>&
  • has value in
  • behaves as if it called f(in, mask)

where the function f is defined as:

void f(std::ios_base& str, std::ios_base::fmtflags mask)
{
    // set specified flags
    str.setf(mask);
}

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🎀 Example 🎀

Run this code 👇

#include <iomanip>
#include <iostream>

int main()
{
    std::cout << std::resetiosflags(std::ios_base::dec)
              << std::setiosflags(  std::ios_base::hex
                                  | std::ios_base::uppercase
                                  | std::ios_base::showbase) << 42 <<
'\n';
}

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⭐ Output ⭐

0X2A

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💀 Defect reports 💀

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

• DR LWG 183 — applied to C++98. Behavior as published: setiosflags could only be used with streams of type std::ostream or std::istream. Correct behavior: usable with any character stream.

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🌈 See also 🌈

• setf — sets specific format flag (public member function of std::ios_base)
• resetiosflags — clears the specified ios_base flags (function)

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that's the whole page, bestie 🫶 source: http://cppreference.com; version/date: 2024.06.10 — and yes, this was the std::setiosflags(3) manual tea ☕💅