std::error_...erator==,!=,(3)

💖 std::error_...erator==,!=,(3) 💖

okay so real talk, bestie: this page is from the <cyan>C++ Standard Libary</cyan> manual — yes, spelled exactly like that in the manual name, “Libary” and all, I’m not fixing it — and it’s the whole group-chat saga of comparing std::error_category objects. 💅

🌸 NAME 🌸

std::error_category::operator==,!=, — std::error_category::operator==,!=,

(yes, the description is literally the same truncated string, iconic behavior, no notes 💀)

✨ Synopsis ✨

the overload lineup, with all the version labels kept exactly as they are:

• (1) (since C++11) — bool operator==( const error_category& rhs ) const noexcept;
• (2) (since C++11) (until C++20) — bool operator!=( const error_category& rhs ) const noexcept;
• (3) (since C++11) (until C++20) — bool operator<( const error_category& rhs ) const noexcept;
• (4) (since C++20) — std::strong_ordering operator<=>( const error_category& rhs ) const noexcept;

Compares to another error category. that’s the whole main character job. here’s the breakdown:

1. Checks whether *this and rhs refer to the same object. 💖
2. Checks whether *this and rhs do not refer to the same object. 🙈
3. Orders *this and rhs by the order of this and &rhs. Equivalent to std::less<const error_category*>()(this, &rhs). 🔥
4. Orders *this and rhs by the order of this and &rhs. Equivalent to std::compare_three_way()(this, &rhs). ⭐

and the synthesized-operator tea: the <, <=, >, >=, and != operators are synthesized from operator<=> (since C++20) and operator== respectively. periodt. 💅

🎀 Parameters 🎀

• rhs — specifies the error_category to compare. 💖

🍓 Return value 🍓

1. true if *this and rhs refer to the same object, false otherwise.
2. true if *this and rhs do not refer to the same object, false otherwise.
3. true if *this is less than rhs as defined by the order of this and &rhs.
4. std::strong_order::less if *this is less than rhs as defined by the order of this and &rhs, otherwise std::strong_order::greater if rhs is less than *this in the order, otherwise std::strong_order::equal.

xoxo, your Unix bestie 💅 — source/version: http://cppreference.com, 2024.06.10, page: std::error_...erator==,!=,(3). 🫶✨