Initializer Lists (std::initializer_list)

When you write std::vector<int> v = {10, 20, 30};, the curly braces aren't a special vector feature. They construct a temporary std::initializer_list<int>, and the vector has a constructor that knows how to consume one. This chapter is about what that type actually is, how the compiler hands it to your constructors and functions, and how to teach your own classes to accept the same brace-list syntax. The next chapter (uniform initialization) covers the broader brace-init story; this one stays focused on std::initializer_list itself.