Minimum and Maximum Algorithms

# clamp() with custom types

## How can I use clamp() with custom types?

To use std::ranges::clamp() with custom types, you need to define the appropriate comparison operators for your type. The spaceship operator (<=>) provides a concise way to implement all the necessary comparison operators.

### Step 1: Define the Custom Type

First, create your custom type and manually implement the spaceship operator (<=>). This will automatically provide the required comparison operators.

#include <algorithm>
#include <iostream>
#include <compare>

struct Player {
int Health;

// Spaceship operator for three-way comparison
std::strong_ordering operator<=>(const Player& other) const {
return Health <=> other.Health;
}

// Equality operator
bool operator==(const Player& other) const {
return Health == other.Health;
}
};

### Step 2: Use std::ranges::clamp()

With the comparison operators defined, you can now use std::ranges::clamp() with instances of your custom type:

#include <algorithm>
#include <iostream>

struct Player {/*...*/};

int main() {
Player p1{50};
Player p2{100};
Player p3{150};

Player clampedPlayer =
std::ranges::clamp(p2, p1, p3);

std::cout << "Clamped Player Health: "
<< clampedPlayer.Health;
}
Clamped Player Health: 100

In this example, std::ranges::clamp() ensures that the Health of p2 stays within the bounds set by p1 and p3. Since p2's Health is already within the range, it remains unchanged.

### Explanation

• Define the Spaceship Operator: The Player struct has the <=> operator defined, which compares Health values using std::strong_ordering. This operator provides functionality for determining the relative ordering of Player objects.
• Define the Equality Operator: The equality operator (==) is explicitly defined to determine whether two Player objects are equal, by comparing their Health values.
• Use std::ranges::clamp(): The std::ranges::clamp() function ensures that p2's Health is clamped between p1's and p3's Health.

By implementing the necessary comparison operators, you enable std::ranges::clamp() to work with your custom types, making your code more flexible and powerful.

This Question is from the Lesson:

### Minimum and Maximum Algorithms

An introduction to the seven minimum and maximum algorithms in the C++ standard library: clamp(), min(), min_element(), max(), max_element(), minmax(), and minmax_element().

Answers to questions are automatically generated and may not have been reviewed.

This Question is from the Lesson:

### Minimum and Maximum Algorithms

An introduction to the seven minimum and maximum algorithms in the C++ standard library: clamp(), min(), min_element(), max(), max_element(), minmax(), and minmax_element().

Part of the course:

## Professional C++

Comprehensive course covering advanced concepts, and how to use them on large-scale projects.

Free, unlimited access

### This course includes:

• 124 Lessons
• 550+ Code Samples
• 96% Positive Reviews
• Regularly Updated
• Help and FAQ
Free, Unlimited Access

### Professional C++

Comprehensive course covering advanced concepts, and how to use them on large-scale projects.