std::basic_...f::showmanyc(3)

✨ std::basic_...f::showmanyc(3) ✨

okay so this page comes from the C++ Standard Libary manual (yes, that's the manual name as written 💖), and it's all about std::basic_streambuf::showmanyc. No cap, it's a virtual protected function, and it's lowkey iconic for anyone doing stream buffer stuff.

🌸 NAME 🌸

std::basic_streambuf::showmanyc — std::basic_streambuf::showmanyc

🌀 Synopsis 🌀

          protected:
          virtual std::streamsize showmanyc();

So bestie, this estimates the number of characters available for input in the associated character sequence. underflow() is guaranteed not to return Traits::eof() or throw an exception until at least that many characters are extracted. Periodt.

🎀 Parameters 🎀

• (none) — literally no parameters, bestie.

💖 Return value 💖

• The number of characters that are certainly available in the associated character sequence.
• Or -1 if showmanyc can determine, without blocking, that no characters are available.
• If showmanyc returns -1, underflow() and uflow() will definitely return Traits::eof or throw.

The base class version returns 0, which has the meaning of "unsure if there are characters available in the associated sequence".

🧠 Notes 🧠

The name of this function stands for "stream: how many characters?", so it is pronounced "S how many C", rather than "show many C". iykyk 🫶

🍓 Example 🍓

This section is incomplete.

Reason: no example.

🛠️ Defect reports 🛠️

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

• DR LWG 159 — applied to C++98.
  • Behavior as published: underflow() is guaranteed not to fail until at least showmanyc() characters are supplied.
  • Correct behavior: extended the guarantee to allow at least showmanyc() characters to be extracted.

👀 See also 👀

• in_avail — obtains the number of characters immediately available in the get area (public member function).
• showmanyc — optionally provides the number of characters available for input from the file [virtual] (virtual protected member function of std::basic_filebuf<CharT,Traits>).

📌 Category 📌

• Todo no example

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that's the whole page, bestie ✨ source: http://cppreference.com, version/date: 2024.06.10, page: std::basic_...f::showmanyc(3). slay 💅