Using std::ranges::for_each() with a Member Function
How do I use std::ranges::for_each() with a member function of a class?
To use std::ranges::for_each() with a member function of a class, you'll need to use a std::bind() or a lambda function to bind the member function to an instance of the class. Here's a simple example to illustrate this process:
First, let's define a class Player with a member function Log():
#include <iostream>
#include <vector>
#include <algorithm>
class Player {
public:
Player(int id) : id{id} {}
void Log() const {
std::cout << "Player ID: " << id << "\n";
}
private:
int id;
};Now, you can create a vector of Player objects and use std::ranges::for_each() to call the Log() member function on each Player object:
#include <algorithm>
#include <iostream>
#include <ranges>
#include <vector>
class Player {
public:
Player(int id) : id{id} {}
void Log() const {
std::cout << "Player ID: " << id << "\n";
}
private:
int id;
};
int main() {
std::vector<Player> players{
Player{1}, Player{2}, Player{3}};
std::ranges::for_each(players, [](Player& p) {
p.Log();
});
}Player ID: 1
Player ID: 2
Player ID: 3In this example, we use a lambda function to call the Log() member function on each Player object. The lambda captures each Player object by reference and calls the Log() method.
Alternatively, you can use std::bind() if you prefer:
#include <algorithm>
#include <functional>
#include <iostream>
#include <ranges>
#include <vector>
class Player {
public:
Player(int id) : id{id} {}
void Log() const {
std::cout << "Player ID: " << id << "\n";
}
private:
int id;
};
int main() {
std::vector<Player> players{
Player{1}, Player{2}, Player{3}};
std::ranges::for_each(players,
std::bind(&Player::Log, std::placeholders::_1)
);
}Player ID: 1
Player ID: 2
Player ID: 3In this second example, std::bind() is used to bind the Log() member function to each Player object.
Both approaches allow you to effectively use std::ranges::for_each() with member functions of a class.
8 Key Standard Library Algorithms
An introduction to 8 more useful algorithms from the standard library, and how we can use them alongside views, projections, and other techniques