可变参数宏__VA_ARGS__
宏定义使用可变参数，使用起来方便多了。具体看msdn例子：
Support for variadic macros was introduced in Visual C++ 2005.
// variadic_macros.cpp#include <stdio.h>#define EMPTY#define CHECK1(x, ...) if (!(x)) { printf(__VA_ARGS__); }#define CHECK2(x, ...) if ((x)) { printf(__VA_ARGS__); }#define CHECK3(...) { printf(__VA_ARGS__); }#define MACRO(s, ...) printf(s, __VA_ARGS__)int main() { CHECK1(0, "here %s %s %s", "are", "some", "varargs1(1)\n"); CHECK1(1, "here %s %s %s", "are", "some", "varargs1(2)\n"); // won't print CHECK2(0, "here %s %s %s", "are", "some", "varargs2(3)\n"); // won't print CHECK2(1, "here %s %s %s", "are", "some", "varargs2(4)\n"); // always invokes printf in the macro CHECK3("here %s %s %s", "are", "some", "varargs3(5)\n"); MACRO("hello, world\n"); // MACRO("error\n", EMPTY); would cause C2059}here are some varargs1(1)here are some varargs2(4)here are some varargs3(5)hello, world