Hi every body, i have a problem with r-value reference and l-value reference issue. i write this sample code

class MemoryBlock
{
public: 
      MemoryBlock(){};
      MemoryBlock(int a){};

};

void g(const MemoryBlock&)
{
   cout << "l-value " << endl;
}

void g(MemoryBlock&&)
{
   cout << "r-value" << endl;
}

void fn(MemoryBlock&& block)
{
   g(block);
}

int main()
{
   fn(MemoryBlock());
   fn(5);
}

i get following output:

   l-value
   r-value 

i think that compiler treats a named rvalue reference as an lvalue and an unnamed rvalue reference as an rvalue. So in both calling modes, the unnamed parameter passed to fn, so why do we have a different response?

what is difference between two constructor of MemoryBlock class?