CONCAT code在C宏 [英] concat code with macro in C

问题描述

事情是这样的：

比方说，我已经用C定义了两个功能：

Let's say I have two function defined in C:

test_1() {};
test_2() {};

我想有一个宏（例如NUM_TEST），将参照测试号。最好的办法是显示它在code：

I would like to have a macro (e.g. NUM_TEST) that will refer to test number. Best way is to show it in code:

#define NUM_TEST 1

test_1() {};
test_2() {};

int main() {
    test_ ## NUM_TEST ## ()
}

我AP preciate，如果有人可以帮助，以找到一个解决方案，如何Concat的函数名宏。

I would appreciate, if someone would help, to find a solution, how to concat name of function with macro.

编辑：

为了使它更清晰。我想仅仅通过不断变化的宏观NUM_TEST改变调用TEST_1之间）和test_2功能（（）

To make it more clear. I would like to just by changing of "macro NUM_TEST" change invoked function between test_1() and test_2().

是的，我知道有更容易的方法来做到这一点，但是这仅仅是一个例子，更一般的问题：如何Concat的宏观与C文本不增加新线路或新的宏功能

Yes I know there are more easier ways to do that, but this is just an example to more general problem: How to concat macro with text in C without adding new lines or new macro functions.

编辑2：

很显然，我现在很清楚。比方说，我写了一个程序。它有两个（或更多）的运行类型。我有一个名为NUM_TEST一个宏。通过设置提到宏观到1或2要选择TEST_1（）之间test_2运行类型或（）

Obviously I was now clear enough. Let's say I wrote a program. It has two (or more) run types. I have one macro called NUM_TEST. By setting mentioned macro to 1 or 2 a want to choose run type between test_1() or test_2()

感谢您！

推荐答案

这是你要找的是什么？

#include <stdio.h>

#define TEST(NUM) test_ ## NUM ()

test_1() { printf ("Hello "); }
test_2() { printf ("World!\n"); }


int main (void)
{
  TEST(1);
  TEST(2);
  // Prints "Hello World!\n"

  return 0;
}

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