Update default_delete.cpp

c++2.0/c++11/default_delete.cpp

@@ -2,8 +2,7 @@
 // Created by light on 19-11-3.
 //
 
-#include <iostream>
-#include <complex>
+#include<bits/stdc++.h>
 
 using namespace std;
 
@@ -104,4 +103,4 @@ int main() {
     Foo foo1;
 //    foo = foo1;   // 继承了的都拥有PrivateCopy性质
     return 0;
-}
+}