Avoid ambiguity

The existence of multiple data conversion routines performing the similar operations, places the compiler in an ambiguous state. That does not know which one to select for conversion. For example, existence of a one-argument constructor in the destination object's class and operator function also in the source object's class performing the similar as conversion function that confuses the compiler; it does not know that one to select and issues and error messages. Thus, prevent defining multiple routines performing the similar operation that become ambiguous during compilation.