std::source...unction_name(3)

🎀 NAME 🎀

std::source_location::function_name — std::source_location::function_name 🫶

Okay so this is the std::source...unction_name(3) page from the C++ Standard Library, and it’s all about std::source_location::function_name. It’s giving “bestie, what function are we even in?” energy. ✨

✨ Synopsis ✨

constexpr const char* function_name() const noexcept;  (since C++20)

This one is available since C++20. It returns the name of the function associated with the position represented by this object — if there even is one. No cap. 💅

🫶 Parameters 🫶

(none) — literally none. No arguments, no sneaky extras. 😌

💖 Return value 💖

If this object represents a position in a body of a function, you get an implementation-defined null-terminated byte string corresponding to the name of the function. Otherwise? An empty string is returned. That’s the whole vibe check. 🦋

🧚 Example 🧚

std::source_location::function_name may help to obtain the names of functions — including the special functions — alongside with their signatures. Obsessed. 💅

Run this code, bestie:

// Run this code

#include <cstdio>
#include <utility>
#include <source_location>

inline void print_function_name(
    const std::source_location& location = std::source_location::current())
{
    std::puts(location.function_name()); // prints the name of the caller
}

void foo(double &&) { print_function_name(); }

namespace bar { void baz() { print_function_name(); } }

template <typename T> auto pub(T) { print_function_name(); return 42; }

struct S {
    S() { print_function_name(); }
    S(int) { print_function_name(); }
    ~S() { print_function_name(); }
    S& operator=(S const&) { print_function_name(); return *this; }
    S& operator=(S&&) { print_function_name(); return *this; }
};

int main(int, char const* const[])
{
    print_function_name();
    foo(3.14);
    bar::baz();
    pub(0xFULL);
    S p;
    S q{42};
    p = q;
    p = std::move(q);
    [] { print_function_name(); }();
}

🌈 Possible output 🌈

int main(int, const char* const*)
void foo(double&&)
void bar::baz()
auto pub(T) [with T = long long unsigned int]
S::S()
S::S(int)
S& S::operator=(const S&)
S& S::operator=(S&&)
main(int, const char* const*)::<lambda()>
S::~S()
S::~S()

👑 See also 👑

• 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)

Mwah 💋 — source: http://cppreference.com, version/date: 2024.06.10, page: std::source...unction_name(3). Byeee bestie 🫶