使用预处理器的字符串连接 [英] String concatenation using preprocessor

问题描述

是否可以在预处理期间连接字符串？

is it possible to concatenate strings during preprocessing?

我发现此示例

#define H "Hello "
#define W "World!"
#define HW H W

printf(HW); // Prints "Hello World!"

但是它不适用于我 - 当我使用 gcc -std = c99

However it does not work for me - prints out "Hello" when I use gcc -std=c99

UPD 此示例看起来像现在工作。

UPD This example looks like working now. However, is it a normal feature of c preprocessor?

推荐答案

邻接字符串乱序的连接不是预处理器的一个特性，它是核心语言（C和C ++）的一个特性。您可以写：

Concatenation of adjacent string litterals isn't a feature of the preprocessor, it is a feature of the core languages (both C and C++). You could write:

printf("Hello "
       " world\n");

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