Remove an unused &[Ty] <-> &[GenericArg]

This commit is contained in:
Maybe Waffle 2023-04-20 12:41:46 +00:00
parent 13fc33e3f2
commit 6d4b7fe9ed

View File

@ -21,7 +21,6 @@
use std::mem; use std::mem;
use std::num::NonZeroUsize; use std::num::NonZeroUsize;
use std::ops::{ControlFlow, Deref}; use std::ops::{ControlFlow, Deref};
use std::slice;
/// An entity in the Rust type system, which can be one of /// An entity in the Rust type system, which can be one of
/// several kinds (types, lifetimes, and consts). /// several kinds (types, lifetimes, and consts).
@ -55,18 +54,6 @@ pub enum GenericArgKind<'tcx> {
Const(ty::Const<'tcx>), Const(ty::Const<'tcx>),
} }
/// This function goes from `&'a [Ty<'tcx>]` to `&'a [GenericArg<'tcx>]`
///
/// This is sound as, for types, `GenericArg` is just
/// `NonZeroUsize::new_unchecked(ty as *const _ as usize)` as
/// long as we use `0` for the `TYPE_TAG`.
pub fn ty_slice_as_generic_args<'a, 'tcx>(ts: &'a [Ty<'tcx>]) -> &'a [GenericArg<'tcx>] {
assert_eq!(TYPE_TAG, 0);
// SAFETY: the whole slice is valid and immutable.
// `Ty` and `GenericArg` is explained above.
unsafe { slice::from_raw_parts(ts.as_ptr().cast(), ts.len()) }
}
impl<'tcx> GenericArgKind<'tcx> { impl<'tcx> GenericArgKind<'tcx> {
#[inline] #[inline]
fn pack(self) -> GenericArg<'tcx> { fn pack(self) -> GenericArg<'tcx> {