std::experi...ce_location(3)

💅 NAME 💅

std::experimental::source_location — bestie, it's literally std::experimental::source_location, that's the whole name, no notes ✨ (and yes, this page lives in the C++ Standard Libary man page, we're all friends here 🫶)

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✨ SYNOPSIS ✨

So first things first, the vibe check on where this lil guy lives:

Defined in header <experimental/source_location>
struct source_location;                           (library fundamentals TS v2)

The source_location class represents certain information about the source code, such as file names, line numbers, and function names. Like, it's giving "who am I, where do I come from" but for code 🔥

Now for the backstory, because it's iconic 👑: previously, functions that desire to obtain this information about the call site (for logging, testing, or debugging purposes) must use macros so that predefined macros like __LINE__ and __FILE__ are expanded in the context of the caller. The source_location class provides a better alternative. Periodt. No more macro spaghetti, we're classy now 💅

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🎀 MEMBER FUNCTIONS 🎀

🌸 Creation

• constructor — constructs a new source_location with implementation-defined values (public member function). Ngl, the values are implementation-defined, so don't come for me if yours look different 🙈
• current [static] — constructs a new source_location (public static member function). This is the main character energy one right here ⭐

🦋 Other special member functions

• destructor (implicitly declared) — destructs a source_location (public member function). It's giving "my time has come" 💀
• operator= (implicitly declared) — implicitly declared copy/move assignment operators (public member function). Free of charge, we love a no-effort slay ✨

💜 Field access

• line — return the line number represented by this object (public member function)
• 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). Note the "if any" — sometimes it just doesn't know, and that's okay 😭

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🌈 EXAMPLE 🌈

Okay so here's the code, run it, it ate fr fr 🔥

// Run this code

#include <experimental/source_location>
#include <iostream>
#include <string_view>

void log(const std::string_view message,
         const std::experimental::source_location location =
               std::experimental::source_location::current())
{
    std::cout << "info:"
              << location.file_name() << ':'
              << location.line() << ' '
              << message << '\n';
}

int main()
{
    log("Hello world!");
}

Look at that default argument doing the absolute most — it's grabbing the call site like a little detective 🕵️‍♀️ obsessed.

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💖 POSSIBLE OUTPUT 💖

Possible output:

info:main.cpp:15 Hello world!

The way it just knows it was main.cpp, line 15... iykyk 🧚

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Okay that's the whole page bestie, hope this was helpful, mwah 🍓

Sign-off szn: this iconic little page came from http://cppreference.com, version 2024.06.10, and it's the std::experi...ce_location(3) page — slay, bye 👋💖