rvalue data member initialization: Aggregate initialization vs constructor

For the code below:

#include <iostream>
#include <memory>
#include <string>
using namespace std;

struct Foo {
    string tag;

    Foo(string t): tag(t){
        cout << "Foo:" << tag << endl;
    }
    ~Foo() {
        cout << "~Foo:" << tag << endl;
    }
};

struct Bar {
    Foo&& foo;
};

struct Baz{
    Foo&& foo;
    Baz(Foo&& f):foo(std::move(f)){

    }
};

int main() {
    Bar bar{Foo("Bar")};
    Baz baz{Foo("Baz")};
    cin.get();
}

result:

Foo:Bar
Foo:Baz
~Foo:Baz

We can see that bar successfully extend the lifetime of a temporary Foo but baz failed to do so. What is the difference between the two? How can I implement the constructor of Baz correctly?

Edit: actually VC++2017 gives:

Foo:Bar
~Foo:Bar
Foo:Baz
~Foo:Baz

So I guess the whole thing is not reliable. Is there any way to make sure that member not destroyed when the holder is alive?