Functional Programming(Chapter 3 of Programming F#)

　　You can easily create properties and methods in F#, so why use a record? Records offer several distinct advantages over traditional object-oriented data structures:

　　• Type inference can infer a record’s type. No need for superfluous type annotations.

　　• Record fields are immutable by default, whereas class types offer no safety guarantee.

　　• Records cannot be inherited, giving a future guarantee of safety.

　　• Records can be used as part of standard pattern matching; classes cannot without resorting to active patterns or when guards.

　　• Records (and discriminated unions) get structural comparison and equality semantics for free.