C++核心准则Enum.8:只在必要时指定枚举值
共 592字,需浏览 2分钟
·
2020-03-19 23:21
Enum.8: Specify enumerator values only when necessary
Enum.8: 只在必要时指定枚举值
Reason(原因)
It's the simplest. It avoids duplicate enumerator values. The default gives a consecutive set of values that is good for switch-statement implementations.
这样最简单。可以避免重复的枚举值。默认的情况会分配一组容易被switch语句使用的连续值。
Example(示例)
enum class Col1 { red, yellow, blue };
enum class Col2 { red = 1, yellow = 2, blue = 2 }; // typo
enum class Month { jan = 1, feb, mar, apr, may, jun,
jul, august, sep, oct, nov, dec }; // starting with 1 is conventional
enum class Base_flag { dec = 1, oct = dec << 1, hex = dec << 2 }; // set of bits
Specifying values is necessary to match conventional values (e.g., Month) and where consecutive values are undesirable (e.g., to get separate bits as in Base_flag).
为了符合日常习惯(例如月)或者不希望连续值(例如用于获取标志变量中的特定标志位)时有必要定义枚举值。
Enforcement(实施建议)
Flag duplicate enumerator values
标记重复的枚举值
Flag explicitly specified all-consecutive enumerator values
标记显式定义所有枚举值为连续值情况。
原文链接:
https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#enum8-specify-enumerator-values-only-when-necessary
觉得本文有帮助?请分享给更多人。
关注【面向对象思考】轻松学习每一天!
面向对象开发,面向对象思考!