本文介绍了在C ++中迭代通过连续枚举值的最简单的方法的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧! 问题描述 在C ++中使用连续值迭代枚举的首选简单方法是什么?我发现以前的SO这个问题涉及创建自定义操作符++ 等,但这似乎过度。到目前为止,我想出的最好的是:What is the preferred simple method for iterating through an enum with contiguous values in C++? I found previous SO questions on this subject which involved creating custom operator++ etc, but this seems like overkill. So far the best I have come up with is:enum { FOO, BAR, BLECH, NUM_ENUMS} MyEnum;//for (MyEnum m = FOO; m < NUM_ENUMS; ++m) // compile error// ...//for (MyEnum m = FOO; m < NUM_ENUMS; m = m + 1) // compile error// ...for (MyEnum m = FOO; m < NUM_ENUMS; m = MyEnum(m + 1)) // OK ? ...从编码风格的角度来看,这是合理的,警告( g ++ -Wall ... 似乎对此感到满意)?Is this reasonable from a coding style perspective and is it likely to generate warnings (g++ -Wall ... seems happy with this) ?推荐答案 这将是未定义的: MyEnum(int(NUM_ENUMS)+ 1)因为保持(4)的值将大于枚举可以表示的值([0,3]);由于您确保 m 严格低于 NUM_ENUMS ,可以安全地使用 MyEnum + 1)。This would have been undefined: MyEnum(int(NUM_ENUMS) + 1) because the value to hold (4) would be greater than what the enum can represent ([0, 3]); since you ensure that m is strictly lower than NUM_ENUMS it is safe to use MyEnum(m + 1).另一方面,请注意,您会遇到自定义枚举的问题,例如:On the other hand, note that you would have issues with customized enums such as:enum OtherEnum { Foo = -1, Bar = 2, Baz = 8, NUM_OTHERENUM};因此不是通用做法。我建议生成的数组迭代,代替:I would advise a generated array to iterate over instead:MyEnum const Values[] = { FOO, BAR, BLECH };请注意,它很容易从枚举的定义生成,无意义的价值(商业智慧)。Note that it is easily generated from the definition of the enum, and also avoid polluting the interface with a nonsensical value (business-wise). 这篇关于在C ++中迭代通过连续枚举值的最简单的方法的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!
10-27 13:48