std::source_location::line(3)

📦 version 2024.07.05, in nixpkgs unstable, opensuse-leap 16.0

💖 std::source_location::line(3) 💖

okay bestie, welcome to the C++ Standard Libary page for std::source_location::line — manual name folded in near the top like a lil’ name tag, because we’re cute AND accurate 🫶

🌸 NAME 🌸

std::source_location::line — std::source_location::line (iconic, no notes 💅)

✨ Synopsis ✨

Here’s the signature, no cap:

constexpr std::uint_least32_t line() const noexcept;  (since C++20)

Returns the line number represented by this object. That’s the whole vibe, fr fr.

🎀 Parameters 🎀

(none) — literally zero parameters, she takes no arguments and still serves 💅

🦋 Return value 🦋

The line number represented by this object. ✨

An implementation is encouraged to return 0 when the line number is unknown. So if you see 0, that’s the “idk” answer — highkey useful to know, iykyk.

💻 Example 💻

Run this code 👇

// Run this code

#include <iostream>
#include <string_view>
#include <source_location>

inline void cur_line(
    const std::string_view message = "",
    const std::source_location& location =
       std::source_location::current())
{
    std::cout
        << location.line() // <- the line # of a call site
        << ") "
        << message;
}

int main()
{
    cur_line("++\n");
    cur_line(); std::cout << "Hello,\n";
    cur_line(); std::cout << "C++20!\n";
    cur_line("--\n");
}

🌈 Output 🌈

17) ++
18) Hello,
19) C++20!
20) --

Ate, periodt. 💖

👀 See also 👀

  • column — return the column number represented by this object (public member function)
  • file_name — return the file name represented by this object (public member function)
  • function_name — return the name of the function represented by this object, if any (public member function)
  • source_line (C++23) — gets the line number that lexically relates the evaluation represented by the stacktrace_entry (public member function of std::stacktrace_entry)
  • Filename and line information

kisses and compiler blessings 💜 — from http://cppreference.com, dated 2024.06.10, for std::source_location::line(3) 🧚

📦 where this page comes from