★23.小窍门收集

输出1-100

模板元编程

// 利用递归继承实现输出0-100
#include 

template 
class X : public X {
public:
    X() { std::cout << N << std::endl; }
};

template <> class X<0> {};

int main() {
    X <100> x;
    return system("pause");
}

宏展开

// 利用宏展开实现输出0-100
#include 
#include 

#define STEP1 ++n <= MAX ? printf("%d\n", n) : 0;
#define STEP2 STEP1 STEP1
#define STEP4 STEP2 STEP2
#define STEP8 STEP4 STEP4
#define STEP16 STEP8 STEP8
#define STEP32 STEP16 STEP16
#define STEP64 STEP32 STEP32
#define STEP128 STEP64 STEP64
#define STEP256 STEP128 STEP128

int n = 0;
const int MAX = 100;

int main() {
    STEP128;
    return system("pause");
}