std::basic_istream::unget(3)

💅 std::basic_istream::unget(3) 💅

okay so bestie, this page is straight out of the C++ Standard Libary manual, and it's all about std::basic_istream::unget. it's giving "put that one character back" energy, and honestly? obsessed. ✨

🌸 NAME 🌸

• std::basic_istream::unget — std::basic_istream::unget (yes, the manual says it twice, iconic 💅)

✨ Synopsis ✨

basic_istream& unget();

it makes the most recently extracted character available again. literally one-character undo, no cap. 🫶

First, it clears eofbit. Then, since C++11, unget behaves as UnformattedInputFunction. After constructing and checking the sentry object, if any ios_base::iostate flags are set, the function sets failbit and returns. Otherwise, it calls rdbuf()->sungetc().

If rdbuf()->sungetc() returns Traits::eof(), it calls setstate(badbit).

In any case, it sets the gcount() counter to zero. periodt. 💅

🎀 Parameters 🎀

• (none) — bestie, it takes no arguments. zero. nada. 🍓

💖 Return value 💖

• *this — yup, it returns the stream itself, main character energy. 👑

🔥 Exceptions 🔥

• failure if an error occurred (the error state flag is not goodbit) and exceptions() is set to throw for that state.
• If an internal operation throws an exception, it is caught and badbit is set. If exceptions() is set for badbit, the exception is rethrown.

🧚 Example 🧚

run this code, bestie:

// Run this code

#include <iostream>
#include <sstream>

int main()
{
    std::istringstream s1("Hello, world.");
    char c1 = s1.get();
    if (s1.unget())
    {
        char c2 = s1.get();
        std::cout << "Got: '" << c1 << "'. Got again: '" << c2 <<
       "'.\n";
    }
}

🌈 Output 🌈

Got: 'H'. Got again: 'H'.

👑 See also 👑

• sungetc — moves the next pointer in the input sequence back by one (public member function of std::basic_streambuf<CharT,Traits>)
• get — extracts characters (public member function)
• peek — reads the next character without extracting it (public member function)
• putback — puts a character into input stream (public member function)

kisses and slay, bestie 💋✨ — source: http://cppreference.com; version/date: 2024.06.10; page: std::basic_istream::unget(3). 🫶💅