Extending base types to conform to custom protocols

Now, we want to be able to use any of the integer types as types in our MutableVector3D<T> and ImmutableVector3D<T> classes. We just need to extend the desired types to make them conform to the previously created NumericForVector protocol.

We want to make the two classes capable of working with elements of any integer type supported in Swift—that is, any of the following types:

• Int

• Int16

• Int32

• Int64

• Int8

• UInt

• UInt16

• UInt32

• UInt64

• UInt8

The following lines extend the previously enumerated types to conform to the NumericForVector protocol:

// Signed integers
extension Int: NumericForVector { }
extension UInt: NumericForVector { }
extension Int16: NumericForVector { }
extension Int32: NumericForVector { }
extension Int64: NumericForVector { }
extension Int8: NumericForVector { }

// Unsigned integers
extension UInt16: NumericForVector { }
extension UInt32: NumericForVector { }
extension UInt64: NumericForVector { }
extension...