在C ++预处理器中组合两个#defined符号 [英] Combining two #defined symbols in C++ preprocessor

问题描述

我想做的事

#define VERSION XY123
#define PRODUCT MyApplication_VERSION

，因此PRODUCT实际上是MyApplication_XY123。我曾尝试与合并运算符##一起玩，但是成功有限。

so that PRODUCT is actually MyApplication_XY123. I have tried playing with the merge operator ## but with limited success...

#define VERSION XY123
#define PRODUCT MyApplication_##VERSION

=> MyApplication_VERSION

=> MyApplication_VERSION

#define VERSION XY123
#define PRODUCT MyApplication_##(VERSION)

=> MyApplication_（XY123）-关闭但不完全

=> MyApplication_(XY123) - close but not quite

我想要什么？

推荐答案

令牌粘贴与宏参数一起使用。所以试试这个

Token pasting works with arguments to macros. So try this

#define VERSION XY123
#define PASTE(x) MyApplication_ ## x
#define PRODUCT PASTE(VERSION)

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