lst-0902-book.cpp
// https://godbolt.org/z/vdT7TTjWK
#include <iostream>
#include <string>
#include <tuple>
#include <map>
#include <unordered_set>
using std::tuple; using std::tie; using std::cout; using std::string;
struct Point {
int x,y,z;
bool operator<(const Point &b) {
return tie(x,y,z) < tie(b.x, b.y, b.z);
}
};
int main() {
Point a{ 11, 22, 33 };
Point b{ 11, 33, 0 };
cout << std::boolalpha << (a < b) << "\n"; // Ausgabe: true
}