Usage automatic duration storage-class specifier with no linkage. type inference (since C23)
The auto keyword can be used as either a storage class specifier or for type inference(since C23).
Notes The constructor and the copy assignment operator from auto_ptr_ref is provided to allow copy-constructing and assigning std::auto_ptr from nameless temporaries. Since its copy constructor and copy assignment operator take the argument as non-const reference, they cannot bind rvalue arguments directly. However, a user-defined conversion can be executed (which releases the original auto ...