The code below warns for the use of the deprecated field:

enum A {
    X{
        #[deprecated(
            since = "0.0.1",
            note = "Don't use this")]
        x: u32
      }
}

fn takeA(a: A) {
    match a {
        A::X{x} => (),
    }
}

warning: use of deprecated field `A::X::x`: Don't use this
  --> src/lib.rs:13:14
   |
13 |         A::X{x} => (),
   |              ^
   |
   = note: `#[warn(deprecated)]` on by default

But I don't see a good way to avoid the warning. I tried matching with A::X{x: _}, but that emits the same warning. If I omit the field entirely, I get an error because the pattern fails to mention field 'x'. If I use A::X{..}, that works, but it applies to all remaining fields, not just x. I want to get an error if, in the future, a new field is added to the enum and I need to consider adding that field to my case.

My suggestion would be to make matching with A::X{x: _} suppress the warning.