warning: type annotations needed
  --> $DIR/inference-variable-behind-raw-pointer.rs:8:13
   |
LL |     if data.is_null() {}
   |             ^^^^^^^
   |
   = note: `#[warn(tyvar_behind_raw_pointer)]` on by default
   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2018 edition!
   = note: for more information, see issue #46906 <https://github.com/rust-lang/rust/issues/46906>