c++函数名地址验证

#include <stdio.h>

typedef void ( *callback_fun )( void );

void fun1( void )
{
 printf( "fun1/r/n" );
}

void fun2( void )
{
 printf( "fun2/r/n" );
}

int main(int argc, char* argv[])
{
 unsigned long addr;
 callback_fun fun;

 printf( "合法的函数地址为%d %d/r/n", ( int )fun1, ( int )fun2 );
 printf( "请输入上面两个中的某一个/r/n" );

 scanf( "%u", &addr );
 fun = ( callback_fun )addr;

 fun();

 return 0;
}