Lambda functions are anonymous functions that you can define in-place within your code. They are objects that can be called, stored, and passed as arguments just like regular functions.

Perfect for use as predicates for STL algorithms (like std::sort or std::find_if), and for defining short callback functions without cluttering the global namespace.

• Creation: $O(1)$.
• Call: $O(1)$ (compiler usually inlines them).

cpp Standard
auto add = [](int a, int b) { return a + b; };
std::cout << add(1, 2); // 3

std::vector<int> v = {3, 1, 2};
std::sort(v.begin(), v.end(), [](int a, int b) {
    return a > b; // Descending order
});

• Capture Errors: Forgetting to capture necessary variables ([=] or [&]).
• Dangling References: Capturing local variables by reference and using the lambda after the variables have gone out of scope.
• Over-complicating: Using lambdas for very complex logic that should probably be a regular function for better readability.