Capturing Class Members in Lambdas

When defining a lambda inside a member function of a class, capturing member variables works a bit differently than capturing local variables. To capture member variables, you need to explicitly use the this pointer.

Here's an example:

1#include <iostream>
2
3class Player {
4  int health{100};
5
6public:
7  void TakeDamage(int amount) {
8    auto PrintHealth{[this] {
9      std::cout << "Remaining Health: "
10        << this->health << '\n';
11    }};
12
13    health -= amount;
14    PrintHealth();
15  }
16};

In this case, we capture this by value in the lambda. This gives us access to all the member variables and functions of the Player class inside the lambda.

Note that we need to use this-> to access the health member inside the lambda.

Alternatively, we could capture this by reference:

1auto PrintHealth{[&] {
2  // No "this->" needed
3  std::cout << health << '\n';
4}};

When capturing this by reference, we can directly access the members without using this->.