std::basic_ios::bad(3)

💅 std::basic_ios::bad 💅

okay so welcome to the C++ Standard Libary corner of the group chat, bestie — this is std::basic_ios::bad(3), and we’re gonna get you fluent in it, no cap. 💖✨

🌸 NAME 🌸

std::basic_ios::bad — std::basic_ios::bad

✨ Synopsis ✨

bool bad() const;

This absolute icon returns true if a non-recoverable error has occurred on the associated stream. Specifically, it returns true if badbit is set in rdstate(). 👑

See ios_base::iostate for the list of conditions that set badbit. iykyk 💅

🎀 Parameters 🎀

Parameters: (none) — literally zero arguments, she takes none, periodt. 🫶

💖 Return value 💖

true if a non-recoverable error has occurred, false otherwise. That’s the whole vibe check, bestie. 🌈

🧪 Example 🧪

okay so run this code, fr fr:

// Run this code

#include <cstdlib>
#include <fstream>
#include <iostream>

int main()
{
    std::ifstream file("test.txt");
    if (!file) // operator! is used here
    {
        std::cout << "File opening failed\n";
        return EXIT_FAILURE;
    }

    // typical C++ I/O loop uses the return value of the I/O function
    // as the loop controlling condition, operator bool() is used here
    for (int n; file >> n;)
       std::cout << n << ' ';
    std::cout << '\n';

    if (file.bad())
        std::cout << "I/O error while reading\n";
    else if (file.eof())
        std::cout << "End of file reached successfully\n";
    else if (file.fail())
        std::cout << "Non-integer data encountered\n";
}

👀 See also 👀

The following table shows the value of basic_ios accessors (good(), fail(), etc.) for all possible combinations of ios_base::iostate flags:

• eofbit = false, failbit = false, badbit = false → good() = true, fail() = false, bad() = false, eof() = false, operator bool = true, operator! = false
• eofbit = false, failbit = false, badbit = true → good() = false, fail() = true, bad() = true, eof() = false, operator bool = false, operator! = true
• eofbit = false, failbit = true, badbit = false → good() = false, fail() = true, bad() = false, eof() = false, operator bool = false, operator! = true
• eofbit = false, failbit = true, badbit = true → good() = false, fail() = true, bad() = true, eof() = false, operator bool = false, operator! = true
• eofbit = true, failbit = false, badbit = false → good() = false, fail() = false, bad() = false, eof() = true, operator bool = true, operator! = false
• eofbit = true, failbit = false, badbit = true → good() = false, fail() = true, bad() = true, eof() = true, operator bool = false, operator! = true
• eofbit = true, failbit = true, badbit = false → good() = false, fail() = true, bad() = false, eof() = true, operator bool = false, operator! = true
• eofbit = true, failbit = true, badbit = true → good() = false, fail() = true, bad() = true, eof() = true, operator bool = false, operator! = true

shoutout to http://cppreference.com for the source/version, dated 2024.06.10, and this was std::basic_ios::bad(3) — mwah, bye bestie! 💋✨🫶