error[E0658]: use of unstable library feature `core_intrinsics`: intrinsics are unlikely to ever be stabilized, instead they should be used through stabilized interfaces in the rest of the standard library
  --> $DIR/unchecked_math_unstable.rs:4:19
   |
LL |         let add = std::intrinsics::unchecked_add(x, y);
   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: add `#![feature(core_intrinsics)]` to the crate attributes to enable
   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date

error[E0658]: use of unstable library feature `core_intrinsics`: intrinsics are unlikely to ever be stabilized, instead they should be used through stabilized interfaces in the rest of the standard library
  --> $DIR/unchecked_math_unstable.rs:5:19
   |
LL |         let sub = std::intrinsics::unchecked_sub(x, y);
   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: add `#![feature(core_intrinsics)]` to the crate attributes to enable
   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date

error[E0658]: use of unstable library feature `core_intrinsics`: intrinsics are unlikely to ever be stabilized, instead they should be used through stabilized interfaces in the rest of the standard library
  --> $DIR/unchecked_math_unstable.rs:6:19
   |
LL |         let mul = std::intrinsics::unchecked_mul(x, y);
   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: add `#![feature(core_intrinsics)]` to the crate attributes to enable
   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date

error: aborting due to 3 previous errors

For more information about this error, try `rustc --explain E0658`.