What are some examples of lambda expressions in C++?

What are some examples of lambda expressions in C++?

Lambda expressions in C++ allow you to create anonymous functions. For example, here's a simple one:

auto add = [](int a, int b) { return a + b; };
int result = add(5, 3); // result is 8

Would you like to see more complex examples?

Yes, can you show me a lambda expression used with STL algorithms?

Certainly! Here's an example using std::sort with a lambda to sort a vector in descending order:

std::vector<int> vec = {1, 4, 2, 8, 5};
std::sort(vec.begin(), vec.end(), [](int a, int b) { return a > b; });

This will sort the vector from highest to lowest. Do you want to explore more about lambda captures?

What are lambda captures?

Lambda captures allow you to use variables from the surrounding scope inside the lambda. For example:

int x = 10;
auto addX = [x](int a) { return a + x; };
int result = addX(5); // result is 15

Here, x is captured by value. Would you like to learn about capturing by reference?

Yes, how do I capture by reference?

To capture by reference, you can use the & symbol. For example:

int x = 10;
auto increment = [&x]() { x++; };
increment(); // x is now 11

This allows the lambda to modify x directly. Do you have any other questions about lambda expressions?