C中实现require 和ensure

// 检查输入条件。

#include<stdio.h>

#include<stdbool.h>

#define require(expression)  do {if( expression != true ) {printf("%s,%d:require check failed.\n",__FILE__,__LINE__);return -1;}}while(0)

int test_require(char * path, int len)

{

    require(path != NULL);

    require(len > 0); 

}

int main()

{

    test_require("a",3);

    test_require(NULL,3);

    test_require("a",0);

}

运行结果：

a.c,7:require check failed.

a.c,8:require check failed.