21.4 Enum values and operations

最新推荐文章于 2021-05-13 11:37:59 发布

最新推荐文章于 2021-05-13 11:37:59 发布 · 83 阅读

本文详细介绍了枚举类型的定义及其与其他整数类型之间的显式转换需求。文中解释了枚举类型可以采用的值不仅限于其成员，并且任何底层类型的值都可以转换为该枚举类型。此外还列举了可以在枚举类型上使用的操作符，并指出每个枚举类型都自动继承自System.Enum类。

Each enum type defines a distinct type; an explicit enumeration conversion (
§13.2.2) is required to convert
between an enum type and an integral type, or between two enum types. The
set of values that an enum type
can take on is not limited by its enum members. In particular, any value of
the underlying type of an enum
can be cast to the enum type, and is a distinct valid value of that enum
type.
Enum members have the type of their containing enum type (except within
other enum member initializers:
see §21.3). The value of an enum member declared in enum type E with
associated value v is (E)v.
The following operators can be used on values of enum types: ==, !=, <, >,
<=, >= (§14.9.5), + (§14.7.4),
- (§14.7.5), ^, &, | (§14.10.2), ~ (§14.6.4), ++, -- (§14.5.9 and §14.6.
5), and sizeof (§25.5.4).
Every enum type automatically derives from the class System.Enum (which, in
turn, derives from
System.ValueType and object). Thus, inherited methods and properties of
this class can be used on
values of an enum type.