From bb5ac03edb1ee162fc6ace8985be98a93ba406f7 Mon Sep 17 00:00:00 2001 From: Scott McMurray Date: Sat, 25 Mar 2023 18:43:03 -0700 Subject: [PATCH] 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. --- src/base.rs | 2 +- src/lib.rs | 2 +- src/unsize.rs | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/src/base.rs b/src/base.rs index 2107ae147e9..1825fb8cb22 100644 --- a/src/base.rs +++ b/src/base.rs @@ -785,7 +785,7 @@ fn is_fat_ptr<'tcx>(fx: &FunctionCx<'_, '_, 'tcx>, ty: Ty<'tcx>) -> bool { let variant_dest = lval.downcast_variant(fx, variant_index); (variant_index, variant_dest, active_field_index) } - _ => (VariantIdx::from_u32(0), lval, None), + _ => (FIRST_VARIANT, lval, None), }; if active_field_index.is_some() { assert_eq!(operands.len(), 1); diff --git a/src/lib.rs b/src/lib.rs index bed79859f51..1bd03403f24 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -86,7 +86,7 @@ mod prelude { self, FloatTy, Instance, InstanceDef, IntTy, ParamEnv, Ty, TyCtxt, TypeAndMut, TypeFoldable, TypeVisitableExt, UintTy, }; - pub(crate) use rustc_target::abi::{Abi, Scalar, Size, VariantIdx}; + pub(crate) use rustc_target::abi::{Abi, Scalar, Size, VariantIdx, FIRST_VARIANT}; pub(crate) use rustc_data_structures::fx::FxHashMap; diff --git a/src/unsize.rs b/src/unsize.rs index ecf187a0b0f..93eefd92342 100644 --- a/src/unsize.rs +++ b/src/unsize.rs @@ -146,7 +146,7 @@ pub(crate) fn coerce_unsized_into<'tcx>( (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) => { assert_eq!(def_a, def_b); - for i in 0..def_a.variant(VariantIdx::new(0)).fields.len() { + for i in 0..def_a.variant(FIRST_VARIANT).fields.len() { let src_f = src.value_field(fx, mir::Field::new(i)); let dst_f = dst.place_field(fx, mir::Field::new(i));