C++ member initializer lists


Not to be confused with std::initializer_list
```typestruct S {    int n;    S(int); // constructor declaration    S() : n(7) {} // constructor definition.                  // ": n(7)" is the initializer list                  // ": n(7) {}" is the function body};S::S(int x) : n{x} {} // constructor definition. ": n{x}" is the initializer listint main(){    S s; // calls S::S()    S s2(10); // calls S::S(int)}```

> [Constructors and member initializer lists](https://en.cppreference.com/w/cpp/language/constructor)
