What the compiler actually generates when you write a C++ lambda expression:

int multiplier = 5;
auto lambda = [multiplier](int x) { return x * multiplier; };

The compiler generates an anonymous unique class (closure type):

class __Lambda_123 {
    int multiplier; // Captured member variable
public:
    __Lambda_123(int m) : multiplier(m) {}
    int operator()(int x) const { return x * multiplier; }
};

A stateless lambda ([](){}) also synthesizes a conversion operator to a plain C function pointer (+lambda), allowing it to be passed directly to legacy C callbacks!

Understanding that lambdas are just standard structs with an operator() method makes lifetime management and capture-by-reference risks so much clearer.

Capturing [&] (by reference) inside a lambda that outlives the enclosing function frame is one of the easiest ways to create dangling stack pointers.