What are lambda expressions in C++ and how do they capture variables?

What are lambda expressions in C++ and how do they capture variables?

Lambda expressions in C++ are a way to create anonymous functions. They can capture variables from their surrounding scope.

Can you explain the different ways to capture variables?

Sure! You can capture variables by value, by reference, or by using a mix of both. For example, [=] captures by value, while [&] captures by reference.

What happens if I capture a variable by reference and it goes out of scope?

If the captured variable goes out of scope, accessing it in the lambda will lead to undefined behavior, as the reference will be invalid.

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

Certainly! Here's a simple example: int x = 10; auto lambda = [&]() { return x + 5; }; This lambda captures x by reference and adds 5 to it.