std::strstreambuf::str(3)

💅 std::strstreambuf::str — C++ Standard Libary (3) ✨

okay bestie, welcome to the <pink>C++ Standard Libary</pink> page for std::strstreambuf::str(3) — this one is a whole little cursed-but-iconic legacy vibe, and we're gonna read it together. 🫶

---

🌸 NAME 🌸

std::strstreambuf::str — std::strstreambuf::str. yes, that's the name, she's serving "function that is literally named after herself" energy 💅

✨ Synopsis ✨

the signature, preserved with love:

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

so here's what she does: calls freeze(), then returns a copy of the start pointer of the get area, std::streambuf::eback(). 🧚

and for all writeable std::strstreambuf objects constructed through the interface provided by std::strstream, the start of the get area is also the start of the put area. iykyk 💫

🎀 Parameters 🎀

• (none) — literally not a single parameter, zero, nada, the void is empty and slaying 🌈

💖 Return value 💖

a copy of eback(), which may be a null pointer. so yes, bestie, check it before you wreck it — null is on the menu 😭

🔥 Notes 🔥

this function is typically called through the std::strstream interface.

the call to freeze() guarantees that the returned pointer remains valid until the next explicit call to freeze(false): otherwise (on a dynamic buffer) any output operation could trigger buffer reallocation which would invalidate the pointer. that's the whole "don't let the buffer move while you're holding the pointer" situation, fr fr 🫶

🚨 warning bestie: it also causes a memory leak in the destructor of std::strstreambuf, unless freeze(false) is called before the buffer (or, more commonly, the std::strstream that manages it) is destroyed. not me warning you about a leak and then still thinking the example is cute 💀

🦋 Example 🦋

the page gives you a // Run this code moment, and the code is:

        #include <iostream>
        #include <strstream>

        int main()
        {
            std::strstream dyn; // dynamically-allocated read/write buffer
            dyn << "Test: " << 1.23 << std::ends;
            std::strstreambuf* buf = dyn.rdbuf();
            std::cout << "R/W buffer holds [" << buf->str() // or dyn.str()
                      << "]\n";
            dyn.freeze(false); // after calling .str() on a dynamic strstream

            char arr[10];
            std::ostrstream user(arr, 10); // fixed-size write-only buffer
            buf = user.rdbuf();
            user << 1.23 << std::ends;
            std::cout << "Write-only buffer holds [" << buf->str() // or
       user.str()
                      << "]\n";

            std::istrstream lit("1 2 3"); // fixed-size read-only buffer
            buf = lit.rdbuf();
            std::cout << "Read-only buffer holds [" << buf->str() // or
       lit.str()
                      << "]\n";
        }

⭐ Output ⭐

R/W buffer holds [Test: 1.23]
Write-only buffer holds [1.23]
Read-only buffer holds [1 2 31 2 3]

👑 See also 👑

• str accesses the output buffer — public member function of std::strstream
• str accesses the output buffer — public member function of std::ostrstream
• str accesses the output buffer — public member function of std::istrstream

---

mwah 💋 — source: http://cppreference.com, date: 2024.06.10, page: std::strstreambuf::str(3). byeee, go call freeze(false) and hydrate 🍓🫶✨