这个程序不能通信编译,说明它并不是运行在运行期,它借助编译错误信息报出'指定范围的素数',比如下面程序将会在primes<x>中x是素数的类中发生错误,看错误信息吧... #include <cstdlib>#include <iostream> using namespace std; struct true_type{       private:               true_type(){};};struct false_type{}; template<bool,typename,typename B>struct IfThenElse{       typedef B result_type;}; template<typename A,typename B>struct IfThenElse<true,A,B>{      typedef A result_type;}; template<int d,int i = d/2 >struct is_prime{      typedef typename IfThenElse<d%i==0,false_type,typename is_prime<d,i-1>::result_type>::result_type result_type;}; template<int d>struct is_prime<d,1>{      typedef true_type result_type;}; template<int d>struct primes{       typedef typename is_prime<d>::result_type result_type;       static void show()       {            result_type y;            primes<d-1>::show();       }}; template<>struct primes<1>{       static void show(){}}; int main(int argc, char *argv[]){    primes<10>::show();    system("PAUSE");    return EXIT_SUCCESS;}   g++.exe -c main.cpp -o main.o -I"D:/Dev-Cpp/lib/gcc/mingw32/3.4.2/include"  -I"D:/Dev-Cpp/include/c++/3.4.2/backward"  -I"D:/Dev-Cpp/include/c++/3.4.2/mingw32"  -I"D:/Dev-Cpp/include/c++/3.4.2"  -I"D:/Dev-Cpp/include"   main.cpp: In static member function `static void primes<d>::show() [with int d = 7]':main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 8]'main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 9]'main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 10]'main.cpp:59:   instantiated from heremain.cpp:9: error: `true_type::true_type()' is private main.cpp:46: error: within this context main.cpp: In static member function `static void primes<d>::show() [with int d = 5]':main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 6]'main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 7]'main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 8]' main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 9]'main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 10]'main.cpp:59:   instantiated from heremain.cpp:9: error: `true_type::true_type()' is privatemain.cpp:46: error: within this contextmain.cpp: In static member function `static void primes<d>::show() [with int d = 3]':main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 4]'main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 5]'main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 6]'main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 7]'main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 8]'main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 9]'main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 10]'main.cpp:59:   instantiated from heremain.cpp:9: error: `true_type::true_type()' is privatemain.cpp:46: error: within this context main.cpp: In static member function `static void primes<d>::show() [with int d = 2]':main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 3]'main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 4]'main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 5]' main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 6]'main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 7]'main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 8]'main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 9]'main.cpp:47:   instantiated from `static void primes<d>::show() [with int d = 10]' main.cpp:59:   instantiated from heremain.cpp:9: error: `true_type::true_type()' is privatemain.cpp:46: error: within this context make.exe: *** [main.o] Error 1 执行结束 1994年Erwin Unruh提供了一个类似的程序。这个程序没什么用，甚至不能运行，但是我觉得很酷，因为它是编译期‘工作’的，我的电脑配置低貌似会很慢，编译起来比较慢。

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