formatting the following code with space_after_colon=false will generate invalid code

struct SomeStruct {
    some_field: ::some_crate::Thing,
}

since it removes the space between the field colon and the :: prefix on some_crate
i cant see this as very high priority because i dont know anyone who prefixes things with :: asides from maybe alloc or std, and space_after_colon=false isnt widely used, but this should probably be looked into