45 struct Foo {  struct
49   constexpr Foo() noexcept = default;  argument
50   constexpr Foo(int x, double y) noexcept : x(x), y(y) { }  in Foo()  argument
52   bool operator==(const Foo &other) const noexcept { return x == other.x && y == other.y; }  in operator ==()  argument
53   bool operator!=(const Foo &other) const noexcept { return !(*this == other); }  in operator !=()  argument
54 …bool operator<(const Foo &other) const noexcept { return std::tie(x, y) < std::tie(other.x, other.…  in operator <()  argument
63   friend std::ostream &operator<<(std::ostream &oss, const Foo &f) noexcept  in operator <<()  argument
74 MAKE_HASHABLE(Foo, t.x, t.y)
668     const auto foo_printer = [](const Foo &key, std::string &buf) {  in main()
701       auto ret = Foo{make_int(), make_double()};  in main()
720 …PetscCall(make_tester<int, Foo, BadHash>(vwr, "int-foo bad hash map", int_printer, foo_printer, in…  in main()
723 …PetscCall(make_tester<Foo, Bar>(vwr, "foo-bar basic map", foo_printer, bar_printer, foo_bar_genera…  in main()
724 …PetscCall(make_tester<Foo, Bar, BadHash>(vwr, "foo-bar bad hash map", foo_printer, bar_printer, fo…  in main()