How do I use three-way comparison (<=>) in C++20?

C++20 introduces the three-way comparison operator, also known as the spaceship operator (<=>). This operator allows for a single, concise way to compare two objects in terms of their order, making it easier to implement comparison logic.

To use the three-way comparison operator, you simply need to implement the operator in your class and use it in place of traditional comparison operators such as <, >, ==, etc. Here's a simple example:

#include #include struct Point { int x, y; auto operator<=> (const Point& other) const = default; }; int main() { Point p1{1, 2}; Point p2{2, 3}; if (p1 < p2) { std::cout << "p1 is less than p2" << std::endl; } else { std::cout << "p1 is not less than p2" << std::endl; } return 0; }

C++20 three-way comparison spaceship operator &lt;=&gt; operator C++ comparison operators

Related Questions

How do I avoid rehashing overhead with std::set in multithreaded code?

How do I find elements with custom comparators with std::set for embedded targets?

How do I erase elements while iterating with std::set for embedded targets?

How do I provide stable iteration order with std::unordered_map for large datasets?

How do I reserve capacity ahead of time with std::unordered_map for large datasets?

How do I erase elements while iterating with std::unordered_map in multithreaded code?

How do I provide stable iteration order with std::map for embedded targets?

How do I provide stable iteration order with std::map in multithreaded code?

How do I avoid rehashing overhead with std::map in performance-sensitive code?

How do I merge two containers efficiently with std::map for embedded targets?