What are advanced lambda expressions in C++?

What are advanced lambda expressions in C++?

Advanced lambda expressions in C++ allow you to create anonymous functions with complex behaviors, including capturing variables by value or reference, specifying return types, and using mutable lambdas.

Can you give me an example of a lambda that captures variables?

Sure! Here's an example:

int x = 10;
auto lambda = [x](int y) { return x + y; };
std::cout << lambda(5); // Outputs 15

This lambda captures x by value.

What about mutable lambdas?

A mutable lambda allows you to modify captured variables. Here's an example:

int x = 10;
auto lambda = [x]() mutable { x += 5; return x; };
std::cout << lambda(); // Outputs 15
std::cout << x; // Outputs 10, x outside remains unchanged

How do I specify a return type for a lambda?

You can specify a return type using the trailing return type syntax. For example:

auto lambda = [](int a, int b) -> int { return a + b; };