std::strstream::str(3)

okay so bestie, welcome to std::strstream::str(3) — straight from the C++ Standard Libary manual, section 3. this page is short but it has lore 💅

💖 NAME 💖

std::strstream::str — yep, that’s the name, and it’s literally std::strstream::str again. no plot twist. 🎀

✨ Synopsis ✨

char* str();  (deprecated in C++98)
              (removed in C++26)

It returns the pointer to the beginning of the buffer, after freezing it. Effectively, it calls rdbuf()->str().

heads up: deprecated in C++98 and removed in C++26, so this is vintage behavior, bestie. 💀

🌸 Parameters 🌸

(none) — no arguments, no params, nothing to pass. 🫶

🦋 Return value 🦋

Pointer to the beginning of the buffer in the associated std::strstreambuf, or a null pointer if no buffer is available. That’s the whole return vibe. ✨

🎀 Notes 🎀

• Before a call to str() that uses the result as a C-string, the stream buffer must be null-terminated. like, actually terminated.
• Regular output such as with stream << 1.2 does not store a null terminator. It must be appended explicitly, typically with the manipulator std::ends.
• After a call to str(), dynamic streams become frozen. 🧊
• A call to freeze(false) is required before exiting the scope in which this strstream object was created. Otherwise the destructor will leak memory. no cap, that’s a leak.
• Also, additional output to a frozen stream may be truncated once it reaches the end of the allocated buffer, which may leave the buffer not null-terminated. so watch out for that.

🧪 Example 🧪

// Run this code — here’s the whole flex:

#include <iostream>
#include <strstream>

int main()
{
    std::strstream dyn; // dynamically-allocated output buffer
    dyn << "Test: " << 1.23; // not adding std::ends to demonstrate append behavior
    std::cout << "The output stream holds \"";
    std::cout.write(dyn.str(), dyn.pcount()) << "\"\n";
    // the stream is now frozen due to str()
    dyn << " More text" << std::ends;
    std::cout << "The output stream holds \"";
    std::cout.write(dyn.str(), dyn.pcount()) << "\"\n";
    dyn.freeze(false);
}

🌈 Possible output: 🌈

The stream holds "Test: 1.23"
The stream holds "Test: 1.23 More "

👀 See also 👀

• str — marks the buffer frozen and returns the beginning pointer of the input sequence (public member function of std::strstreambuf). 💜

okay that’s the page, bestie. source: http://cppreference.com; date on this one: 2024.06.10. periodt 💖✨