从 C++ 宏创建字符串列表和枚举列表

问题描述

为了使我的代码更短更容易更改，我想替换类似的东西

In order to make my code shorter and easier to change I want to replace something like

enum{ E_AAA, E_BBB, E_CCC };
static const char *strings{"AAA", "BBB", "CCC" };

使用宏，例如 INIT(AAA, BBB, CCC);但是当我尝试使用可变参数和字符串化做一个宏时，我得到一个错误，因为没有声明参数.

With a macro, like INIT(AAA, BBB, CCC); but when I try doing a macro with variable arguments, and stringification I get an error as the arguments are not declared.

你知道怎么做吗?

推荐答案

这是我前几天学到的一个解决方案.处理您的问题的简化版是:

Here a solution I learned a few days ago. The simplified version that attends your question is:

#define ENUM_MACRO(name, v1, v2, v3, v4, v5, v6, v7)
    enum name { v1, v2, v3, v4, v5, v6, v7};
    const char *name##Strings[] = { #v1, #v2, #v3, #v4, #v5, #v6, #v7};

ENUM_MACRO(Week, Sun, Mon, Tue, Wed, Thu, Fri, Sat);

但您可以使用函数调用的改进版本，如下所示:

But you can have an improved version, with a function call, like this:

#define ENUM_MACRO(name, v1, v2, v3, v4, v5, v6, v7)
    enum name { v1, v2, v3, v4, v5, v6, v7};
    const char *name##Strings[] = { #v1, #v2, #v3, #v4, #v5, #v6, #v7};
    const char *name##ToString(value) { return name##Strings[value]; }

ENUM_MACRO(Week, Sun, Mon, Tue, Wed, Thu, Fri, Sat);

这将变成:

  enum Week { Sun, Mon, Tue, Wed, Thu, Fri, Sat};
  const char *WeekStrings[] = { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
  const char *WeekToString(value) { return WeekStrings[value]; };

您甚至可以对第一个元素使用 偏移量，如下所示:

You can even use an offset for the first element, like this one:

#define ENUM_MACRO(name, offset, v1, v2, v3, v4, v5, v6, v7)
    enum name { v1 =  offset, v2, v3, v4, v5, v6, v7};
    const char *name##Strings[] = { #v1, #v2, #v3, #v4, #v5, #v6, #v7};
    const char *name##ToString(value) { return name##Strings[value - offset ]; }

ENUM_MACRO(Week, 1, Sun, Mon, Tue, Wed, Thu, Fri, Sat);

我希望这会有所帮助.

保重，贝科

参考:

打印月份问题，由 Kush 回答丹尼·瓦罗德

Print the month question, by Kush, answer by Danny Varod

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