What are some advanced examples of lambda capture in C++?

What are some advanced examples of lambda capture in C++?

Lambda capture in C++ allows you to access variables from the surrounding scope. An advanced example is capturing by reference and value simultaneously. Would you like to see a code snippet?

Yes, please provide a code snippet.

Here's an example:

#include <iostream>
#include <vector>

int main() {
    int x = 10;
    std::vector<int> vec = {1, 2, 3};
    auto lambda = [&x, vec]() {
        x += 5;
        for (int n : vec) {
            std::cout << n + x << " ";
        }
    };
    lambda(); // Outputs: 16 17 18 
    std::cout << "\n" << x; // Outputs: 15
}

This captures x by reference and vec by value.

What happens if I modify x inside the lambda?

If you modify x inside the lambda, it will change the value of x in the outer scope since it's captured by reference. In the example, x becomes 15 after the lambda is executed.

Can you explain the difference between capturing by value and by reference?

Sure! Capturing by value creates a copy of the variable, so changes inside the lambda won't affect the original variable. Capturing by reference allows the lambda to modify the original variable directly.