Explanation:
Closures bind late: each lambda looks up i when it is called, and by then i is 2. Writing lambda i=i: i would capture the value at creation instead.

ALSO KNOW (related points):
• What is the value of an uninitialized local (automatic) int variable in C++? → Indeterminate (garbage); reading it is undefined behavior
• Which keyword lets a Python function assign a new value to a module-level variable? → global
• What happens if a const int variable is declared in C++ without an initializer (const int k;)? → Compilation error