Deriving error: this field does not implement `Copy`

[Voronar]

Hello.
I have the code:

enum Things { A, B, C };

enum sumtype {
  one = 0,
  two = 1
};

struct Baz {
	int x;
	int y;
	//Things things<>; // if uncomment then works
	sumtype *e;
};

Error is:

#[derive( Copy , Clone , Debug , Eq , PartialEq )] pub enum sumtype { one = 0isize , two = 1isize , }

11 | #[derive( Copy , Clone , Debug , Eq , PartialEq )] pub struct Baz { pub x : i32 , pub y : i32 , pub e : Option < Box < sumtype >> , }
   |           ^^^^                                                                                  --------------------------------- this field does not implement `Copy`

If uncomment //Things things<>; then it is ok (Copy attribute has gone from Baz):

#[derive( Copy , Clone , Debug , Eq , PartialEq )] pub enum sumtype { one = 0isize , two = 1isize , }
#[derive( Clone , Debug , Eq , PartialEq )] pub struct Baz { pub x : i32 , pub y : i32 , pub thing : Vec < Things > , pub e : Option < Box < sumtype >> , }

[Voronar]

Box type can not be copied, but it used in code generator (Option case) to make recursive types possible.

[Voronar]

Adding & !COPY to return value here https://github.com/jsgf/rust-xdr/blob/master/xdrgen/src/spec/mod.rs#L254 makes it working and all test passes.

[Voronar]

Fixed #36