lst-0032-book.cpp
// https://godbolt.org/z/Gfrd5cceG
#include <string>
#include <string_view>
using std::string; using sview = std::string_view;
struct Person {
string name_;
int age_;
string city_;
Person(sview n = "N.N.", int a = 18, sview c = "Berlin")
: name_(n), age_(a), city_(c) { }
};