Yes, the <=>
(spaceship) operator can be used for sorting algorithms in C++20. The spaceship operator allows you to define a single comparison function that can be used by sorting algorithms to determine the order of elements.
When you define the <=>
operator for your custom type, you provide a way to compare two instances of that type. Sorting algorithms, like std::sort()
, can then use this comparison logic to sort a collection of your custom objects.
Let’s consider a Player
class where we want to sort players by their scores using the spaceship operator:
#include <iostream>
#include <vector>
#include <algorithm>
#include <compare>
#include <string>
class Player {
public:
Player(std::string name, int score)
: Name{name}, Score{score} {}
std::strong_ordering operator<=>(
const Player& Other) const {
return Score <=> Other.Score;
}
std::string Name;
int Score;
};
int main() {
std::vector<Player> players{
{"Alice", 20}, {"Bob", 15}, {"Charlie", 25}
};
std::sort(players.begin(), players.end());
for (const auto& player : players) {
std::cout << player.Name
<< " - " << player.Score << "\n";
}
}
Bob - 15
Alice - 20
Charlie - 25
In this example, we define the <=>
operator for the Player
class to compare players by their scores. When we call std::sort()
, it uses this comparison logic to sort the players in ascending order of their scores.
<=>
operator ensures that all comparisons are consistent across your program.Using the <=>
operator with sorting algorithms in C++20 simplifies your code and ensures consistency in how your custom types are compared. It leverages the power of the spaceship operator to provide a clear and concise way to define sorting logic.
Answers to questions are automatically generated and may not have been reviewed.
A guide to simplifying our comparison operators using C++20 features