Allow currently unused tuple struct fields

compiler/rustc_borrowck/src/lib.rs

@@ -110,7 +110,7 @@ struct Upvar<'tcx> {
 }
 
 /// Associate some local constants with the `'tcx` lifetime
-struct TyCtxtConsts<'tcx>(TyCtxt<'tcx>);
+struct TyCtxtConsts<'tcx>(#[allow(unused_tuple_struct_fields)] TyCtxt<'tcx>);
 impl<'tcx> TyCtxtConsts<'tcx> {
     const DEREF_PROJECTION: &'tcx [PlaceElem<'tcx>; 1] = &[ProjectionElem::Deref];
 }

compiler/rustc_infer/src/infer/nll_relate/mod.rs

@@ -114,7 +114,7 @@ pub trait TypeRelatingDelegate<'tcx> {
 }
 
 #[derive(Copy, Clone)]
-struct UniversallyQuantified(bool);
+struct UniversallyQuantified(#[allow(unused_tuple_struct_fields)] bool);
 
 impl<'me, 'tcx, D> TypeRelating<'me, 'tcx, D>
 where

compiler/rustc_mir_transform/src/check_unsafety.rs

@@ -385,7 +385,7 @@ pub(crate) fn provide(providers: &mut Providers) {
 enum Context {
     Safe,
     /// in an `unsafe fn`
-    UnsafeFn(HirId),
+    UnsafeFn(#[allow(unused_tuple_struct_fields)] HirId),
     /// in a *used* `unsafe` block
     /// (i.e. a block without unused-unsafe warning)
     UnsafeBlock(HirId),

compiler/rustc_resolve/src/lib.rs

@@ -175,7 +175,7 @@ impl<'a> ParentScope<'a> {
 #[derive(Copy, Debug, Clone)]
 enum ImplTraitContext {
     Existential,
-    Universal(LocalDefId),
+    Universal(#[allow(unused_tuple_struct_fields)] LocalDefId),
 }
 
 #[derive(Debug)]

library/alloc/src/boxed/thin.rs

@@ -171,7 +171,7 @@ struct WithHeader<H>(NonNull<u8>, PhantomData<H>);
 /// An opaque representation of `WithHeader<H>` to avoid the
 /// projection invariance of `<T as Pointee>::Metadata`.
 #[repr(transparent)]
-struct WithOpaqueHeader(NonNull<u8>);
+struct WithOpaqueHeader(#[allow(unused_tuple_struct_fields)] NonNull<u8>);
 
 impl WithOpaqueHeader {
     #[cfg(not(no_global_oom_handling))]

src/librustdoc/clean/types.rs

@@ -2546,7 +2546,7 @@ pub(crate) enum TypeBindingKind {
 pub(crate) enum SubstParam {
     Type(Type),
     Lifetime(Lifetime),
-    Constant(Constant),
+    Constant(#[allow(unused_tuple_struct_fields)] Constant),
 }
 
 impl SubstParam {