Skip to content

Commit

Permalink
Use a const ParamEnv when in default_method_body_is_const
Browse files Browse the repository at this point in the history
  • Loading branch information
fee1-dead committed Dec 17, 2021
1 parent 9b45f04 commit a1f91aa
Show file tree
Hide file tree
Showing 3 changed files with 43 additions and 1 deletion.
8 changes: 7 additions & 1 deletion compiler/rustc_ty_utils/src/ty.rs
Original file line number Diff line number Diff line change
Expand Up @@ -3,7 +3,7 @@ use rustc_hir as hir;
use rustc_hir::def_id::{DefId, LocalDefId};
use rustc_middle::ty::subst::Subst;
use rustc_middle::ty::{self, Binder, Predicate, PredicateKind, ToPredicate, Ty, TyCtxt};
use rustc_span::Span;
use rustc_span::{sym, Span};
use rustc_trait_selection::traits;

fn sized_constraint_for_ty<'tcx>(
Expand Down Expand Up @@ -285,6 +285,12 @@ fn param_env(tcx: TyCtxt<'_>, def_id: DefId) -> ty::ParamEnv<'_> {

let constness = match hir_id {
Some(hir_id) => match tcx.hir().get(hir_id) {
hir::Node::TraitItem(hir::TraitItem { kind: hir::TraitItemKind::Fn(..), .. })
if tcx.has_attr(def_id, sym::default_method_body_is_const) =>
{
hir::Constness::Const
}

hir::Node::Item(hir::Item { kind: hir::ItemKind::Const(..), .. })
| hir::Node::Item(hir::Item { kind: hir::ItemKind::Static(..), .. })
| hir::Node::TraitItem(hir::TraitItem {
Expand Down
Original file line number Diff line number Diff line change
@@ -0,0 +1,17 @@
#![feature(const_fn_trait_bound)]
#![feature(const_trait_impl)]

trait Tr {}
impl Tr for () {}

const fn foo<T>() where T: ~const Tr {}

pub trait Foo {
#[default_method_body_is_const]
fn foo() {
foo::<()>();
//~^ ERROR the trait bound `(): Tr` is not satisfied
}
}

fn main() {}
Original file line number Diff line number Diff line change
@@ -0,0 +1,19 @@
error[E0277]: the trait bound `(): Tr` is not satisfied
--> $DIR/default-method-body-is-const-body-checking.rs:12:15
|
LL | foo::<()>();
| ^^ the trait `Tr` is not implemented for `()`
|
note: required by a bound in `foo`
--> $DIR/default-method-body-is-const-body-checking.rs:7:28
|
LL | const fn foo<T>() where T: ~const Tr {}
| ^^^^^^^^^ required by this bound in `foo`
help: consider introducing a `where` bound, but there might be an alternative better way to express this requirement
|
LL | pub trait Foo where (): Tr {
| ++++++++++++

error: aborting due to previous error

For more information about this error, try `rustc --explain E0277`.

0 comments on commit a1f91aa

Please sign in to comment.