Converting to Reference Types
Any object whose address can be converted to a given pointer type can also be converted to the analogous reference type. For example, any object whose address can be converted to type char * can also be converted to type char &. No constructors or class conversion functions are called to make a conversion to a reference type.
Objects or values can be converted to class-type objects only if a constructor or conversion operator has been provided specifically for this purpose. For more information about these user-defined functions, see Conversion Constructors.
Conversion of a reference to a base class, to a reference to a derived class (and vice versa) is done the same way as for pointers.
A cast to a reference type results in an l-value. The results of casts to other types are not l-values. Operations performed on the result of a pointer or reference cast are still performed on the original object.