lst-0031-book.cpp
// https://godbolt.org/z/8h93f64Yj
#include <string>
#include <string_view>
using std::string; using sview = std::string_view;
struct Person {
string name_;
int age_;
string city_;
Person(sview n, int a, sview c) // delegated constructor
: name_(n), age_(a), city_(c) { } // … implemented
Person() : Person{"no name",-1,"no city"} { } // delegating
Person(sview n, int a) : Person{n, a, "no city"} { } // delegating
Person(sview n) : Person{n, -1, "no city"} { } // delegating
};