Array#delete is destructive, String#delete isn't

Hi,

Array has #- for non-destructively removing elements and #delete for
destructively removing them;
Hash only has #delete for destructively removing elements.

String has #delete for non-destructively removing elements and
#delete! for destructively removing them:

a = [1, 2, 3]
a - [2] # => [1, 3]
a # => [1, 2, 3]
a.delete(2)
a # => [1, 3]

s = "hello world"
s.delete("h") # => "ello world"
s # => "hello world"
s.delete!("h")
s # => "ello world"

The different meaning of delete() for String is just confusing.
Fortunately, it isn't used much.
I think it should be made consistent with Array and Hash.

I understand that this can't be changed in 1.8. What about 1.9?

Kind regards,
Florian Gross