R-value passed to function by reference C++

Question

I have a question about code below, exactly passing r-value arguments to function in C++. Why we can't pass r-value object Rect to function Print(Rect&), but r-value int we can.

I know we can use Print(const int&) or Print(int&&). But the main question is why my own r-value object can be passed?

Thanks in advance for explanation.

#include <iostream>

struct Rect{
    uint32_t a, b;
    Rect(uint32_t a, uint32_t b): a(a), b(b){
        std::cout << "Rect constructor..." << std::endl;
    }
    ~Rect(){
        std::cout << "Rect destructor..." << std::endl;
    }
    Rect( const Rect& rhs ): a(rhs.a), b(rhs.b){
        std::cout << "Rect copy constructor..." << std::endl;
    }
};

void Print(Rect& r){
    std::cout << "a = " << r.a << ", b = " << r.b << std::endl;
}

void Print(int& a){
    std::cout << "a = " << a << std::endl;
}

int main(){
    Print( Rect( 2, 5 ) );

    Print( 5 );

    return 0;
}