wip with boxy

Author: tiif

compiler/rustc_hir/src/lang_items.rs

@@ -369,7 +369,6 @@ language_item_table! {
     CoercePointeeValidated, sym::coerce_pointee_validated, coerce_pointee_validated_trait, Target::Trait,     GenericRequirement::Exact(0);
 
     ConstParamTy,            sym::const_param_ty,      const_param_ty_trait,       Target::Trait,          GenericRequirement::Exact(0);
-    UnsizedConstParamTy,     sym::unsized_const_param_ty, unsized_const_param_ty_trait, Target::Trait, GenericRequirement::Exact(0);
 
     Poll,                    sym::Poll,                poll,                       Target::Enum,           GenericRequirement::None;
     PollReady,               sym::Ready,               poll_ready_variant,         Target::Variant,        GenericRequirement::None;

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -819,7 +819,7 @@ fn check_param_wf(tcx: TyCtxt<'_>, param: &ty::GenericParamDef) -> Result<(), Er
             let span = tcx.def_span(param.def_id);
             let def_id = param.def_id.expect_local();
 
-            if tcx.features().adt_const_params() || tcx.features().unsized_const_params() {
+            if tcx.features().adt_const_params() {
                 // fixme: should we get rid of the check for LangItem::ConstParamTy? If yes, how should we check
                 // if the trait is implemented.
                 enter_wf_checking_ctxt(tcx, tcx.local_parent(def_id), |wfcx| {

library/core/src/marker.rs

@@ -1078,12 +1078,13 @@ pub trait Tuple {}
 /// that all fields are also `ConstParamTy`, which implies that recursively, all fields
 /// are `StructuralPartialEq`.
 #[lang = "const_param_ty"]
+#[unstable(feature = "unsized_const_params", issue = "95174")]
 #[diagnostic::on_unimplemented(message = "`{Self}` can't be used as a const parameter type")]
 #[allow(multiple_supertrait_upcastable)]
 // We name this differently than the derive macro so that the `adt_const_params` can
 // be used independently of `unsized_const_params` without requiring a full path
 // to the derive macro every time it is used. This should be renamed on stabilization.
-pub trait ConstParamTy: StructuralPartialEq + Eq {}
+pub trait ConstParamTy_: StructuralPartialEq + Eq {}
 
 /// Derive macro generating an impl of the trait `ConstParamTy`.
 #[rustc_builtin_macro]
@@ -1096,7 +1097,6 @@ pub macro ConstParamTy($item:item) {
 // FIXME(adt_const_params): handle `ty::FnDef`/`ty::Closure`
 marker_impls! {
     #[unstable(feature = "adt_const_params", issue = "95174")]
-    #[unstable_feature_bound(adt_const_params)]
     ConstParamTy for
         usize, u8, u16, u32, u64, u128,
         isize, i8, i16, i32, i64, i128,

tests/ui/const-generics/adt_const_params/auxiliary/unsized_const_param.rs

@@ -1,6 +1,6 @@
 #![feature(adt_const_params, unsized_const_params)]
 
-#[derive(std::marker::UnsizedConstParamTy, Eq, PartialEq)]
+#[derive(std::marker::ConstParamTy, Eq, PartialEq)]
 pub struct Foo([u8]);
 
 #[derive(std::marker::ConstParamTy, Eq, PartialEq)]

tests/ui/const-generics/adt_const_params/unsized_field-1.rs

@@ -17,4 +17,8 @@ struct B(&'static [u8]);
 //~^ ERROR: the trait `ConstParamTy_` cannot be implemented for this type
 struct C(unsized_const_param::Foo);
 
+#[derive(std::marker::ConstParamTy, Eq, PartialEq)]
+//~^ ERROR: the trait `ConstParamTy_` cannot be implemented for this type
+struct D(unsized_const_param::GenericNotUnsizedParam<&'static [u8]>);
+
 fn main() {}

tests/ui/const-generics/adt_const_params/unsized_field-2.rs

@@ -2,13 +2,13 @@
 #![feature(adt_const_params, unsized_const_params)]
 //~^ WARN: the feature `unsized_const_params` is incomplete
 
+
+// TODO: remove test
+
 extern crate unsized_const_param;
 
-#[derive(std::marker::ConstParamTy, Eq, PartialEq)]
-//~^ ERROR: the trait `ConstParamTy_` cannot be implemented for this type
-struct A(unsized_const_param::GenericNotUnsizedParam<&'static [u8]>);
 
-#[derive(std::marker::UnsizedConstParamTy, Eq, PartialEq)]
+#[derive(std::marker::ConstParamTy, Eq, PartialEq)]
 struct B(unsized_const_param::GenericNotUnsizedParam<&'static [u8]>);
 
 fn main() {}