A Simple C++ template

#include <stdio.h>

//#define FILE
//#define DEBUG

#ifdef DEBUG
#define LOG_PRINTF(format, ...) \
    printf("<"__FILE__">(%05d): "format"", __LINE__, ##__VA_ARGS__)
#else
#define LOG_PRINTF(format, ...)
#endif

int main()
{
#ifdef FILE
    freopen("data.in", "r", stdin);
    freopen("data.out", "w", stdout);
#endif

    LOG_PRINTF("Hello world!\n");

    return 0;
}