DirectiveList::into_iter unexpectedly yields references

[BrynCooke]

DirectiveList::into_iter unexpectedly yields references.
I'd expect a function name into_iter to iterate over owned values.

  let list = DirectiveList::new();
  list.into_iter().map(|d: &Node<Directive>| d  ) // &Node!

Standard Vec:

  let list = vec![1, 2];
  list.into_iter().map(|d: i32| d  ); // Owned

[SimonSapin]

DirectiveList itself does not have into_iter, so in this example code the compiler implicitly adds a reference like (&list).into_iter() to call the trait impl for &'_ DirectiveList:

apollo-rs/crates/apollo-compiler/src/ast/impls.rs

Lines 599 to 607 in 0fa07a8

	impl<'a> IntoIterator for &'a DirectiveList {
	type Item = &'a Node<Directive>;
	type IntoIter = std::slice::Iter<'a, Node<Directive>>;
	fn into_iter(self) -> Self::IntoIter {
	self.0.iter()
	}
	}

This impl exists to make code like for dir in &something.directives work. We can add an owned impl IntoIterator for DirectiveList to make this example behave as expected.

In what kind of situation do you manipulate an owned DirectiveList?

[BrynCooke]

I hadn't realized that into_iter may yeild reference, owned or mut ref depending on context.

I think implementing IntoIterator would still be a nice thing, the exact usecase I don't remember as the code was a conversion of some apollo-smith logic that eventually got deleted anyway. It was just an unexpected surprise.