Refactor: VariantIdx::from_u32(0) -> FIRST_VARIANT

Since structs are always `VariantIdx(0)`, there's a bunch of files where the only reason they had `VariantIdx` or `vec::Idx` imported at all was to get the first variant.

So this uses a constant for that, and adds some doc-comments to `VariantIdx` while I'm there, since it doesn't have any today.
This commit is contained in:
Scott McMurray 2023-03-25 18:43:03 -07:00
parent 96bd50dd47
commit 0439d13176
25 changed files with 80 additions and 78 deletions

View file

@ -17,7 +17,7 @@ use rustc_middle::ty::{self, InstanceDef, ParamEnv, Ty, TyCtxt, TypeVisitableExt
use rustc_mir_dataflow::impls::MaybeStorageLive;
use rustc_mir_dataflow::storage::always_storage_live_locals;
use rustc_mir_dataflow::{Analysis, ResultsCursor};
use rustc_target::abi::{Size, VariantIdx};
use rustc_target::abi::{Size, FIRST_VARIANT};
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
enum EdgeKind {
@ -359,7 +359,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
check_equal(self, location, *f_ty);
}
ty::Adt(adt_def, substs) => {
let var = parent_ty.variant_index.unwrap_or(VariantIdx::from_u32(0));
let var = parent_ty.variant_index.unwrap_or(FIRST_VARIANT);
let Some(field) = adt_def.variant(var).fields.get(f.as_usize()) else {
fail_out_of_bounds(self, location);
return;