Structs
- An I/O port, representing a specific address in the I/O address of x86.
 - An access marker type indicating that a port is only allowed to read values.
 - An access marker type indicating that a port is allowed to read or write values.
 - An access marker type indicating that a port is only allowed to write values.
 
Traits
- A marker trait for access types which allow reading port values.
 - A marker trait for access types which allow writing port values.
 - A helper trait that implements the read port operation.
 - A helper trait that implements the write port operation.