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#pragma预处理实例
1.#include <stdio.h>
#if defined(ANDROID20)
#pragma message("Compile Android SDK 2.0...")
#define VERSION "Android 2.0"
#elif defined(ANDROID23)
#pragma message("Compile Android SDK 2.3...")
#define VERSION "Android 2.3"
#elif defined(ANDROID40)
#pragma message("Compile Android SDK 4.0...")
#define VERSION "Android 4.0"
#else
#error Compile Version is not provided!
#endif
int main()
{
printf("%s\n", VERSION);
return 0;
}
2.#include <stdio.h>
#pragma pack(8)
struct S1
{
short a;
long b;
};
struct S2
{
char c;
struct S1 d;
double e;
};
#pragma pack()
int main()
{
struct S2 s2;
printf("%d\n", sizeof(struct S1));
printf("%d\n", sizeof(struct S2));
printf("%d\n", (int)&(s2.d) - (int)&(s2.c));
return 0;
}
#pragma预处理实例