D语言静态if

import std.stdio;

enum Days { 
   sun, 
   mon, 
   tue, 
   wed, 
   thu, 
   fri, 
   sat 
}; 

void myFunction(T)(T mytemplate) {
   static if (is (T == class)) { 
      writeln("This is a class type"); 
   } else static if (is (T == enum)) { 
      writeln("This is an enum type"); 
   } 
}

void main() { 
   Days day; 
   myFunction(day); 
}