可以将#defines的列表转换为字符串 [英] Possible to convert list of #defines into strings

问题描述

假设我在外部库的头文件中有一个 #define 的列表。这些 #define 表示从函数返回的错误代码。我想写一个转换函数，它可以作为输入一个错误代码，并返回一个字符串文字表示实际的 #define 名称。

Suppose I have a list of #defines in a header file for an external library. These #defines represent error codes returned from functions. I want to write a conversion function that can take as an input an error code and return as an output a string literal representing the actual #define name.

例如，如果我有

#define NO_ERROR 0
#define ONE_KIND_OF_ERROR 1
#define ANOTHER_KIND_OF_ERROR 2

我想要一个函数能够调用

I would like a function to be able to called like

int errorCode = doSomeLibraryFunction();
if (errorCode)
    writeToLog(convertToString(errorCode));

并且拥有 convertToString（）自动转换该错误代码，而不是一个巨大的开关情况下看起来像

And have convertToString() be able to auto-convert that error code without being a giant switch-case looking like

const char* convertToString(int errorCode)
{
    switch (errorCode)
    {
        case NO_ERROR:
           return "NO_ERROR";
        case ONE_KIND_OF_ERROR:
           return "ONE_KIND_OF_ERROR";
        ...
     ...
...

我有一个感觉，如果这是可能的，可能使用模板和元编程，但只有工作的错误代码实际上是一个类型，而不是一堆处理器宏。

I have a feeling that if this is possible, it would be possible using templates and metaprogramming, but that would only work the error codes were actually a type and not a bunch of processor macros.

推荐答案

我通常做巨大的开关case方式，虽然我使它有点更容易：

I normally do it the giant switch case way, although I make it somewhat easier with:

#define STR(code) case code: return #code
switch (errorCode)
{
    STR(NO_ERROR);
    STR(ONE_KIND_OF_ERROR);
}

这是一个很好的问题，有

This is a good question, I'm interested to see what better ways people have

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