C++ 枚举是有符号的还是无符号的? [英] Are C++ enums signed or unsigned?

问题描述

C++ 枚举是有符号的还是无符号的?通过扩展，通过检查输入是否<=您的最大值，并忽略>=您的最小值(假设您从 0 开始并以 1 递增)来验证输入是否安全?

Are C++ enums signed or unsigned? And by extension is it safe to validate an input by checking that it is <= your max value, and leave out >= your min value (assuming you started at 0 and incremented by 1)?

推荐答案

您不应该依赖任何特定的表示.阅读以下链接.此外，该标准还规定，使用哪种整数类型作为枚举的基础类型是实现定义的，但它不得大于 int，除非某些值不能放入 int 或无符号 int.

You shouldn't rely on any specific representation. Read the following link. Also, the standard says that it is implementation-defined which integral type is used as the underlying type for an enum, except that it shall not be larger than int, unless some value cannot fit into int or an unsigned int.

简而言之:你不能依赖一个有符号或无符号的枚举.

In short: you cannot rely on an enum being either signed or unsigned.

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