support as _ and add tests

This commit is contained in:
Ellen 2021-06-10 14:53:38 +01:00
parent c318364d48
commit 17cd79090e
6 changed files with 220 additions and 3 deletions

View file

@ -431,7 +431,9 @@ impl<'a, 'tcx> AbstractConstBuilder<'a, 'tcx> {
}
}
// These are not actually relevant for us here, so we can ignore them.
StatementKind::StorageLive(_) | StatementKind::StorageDead(_) => Ok(()),
StatementKind::AscribeUserType(..)
| StatementKind::StorageLive(_)
| StatementKind::StorageDead(_) => Ok(()),
_ => self.error(Some(stmt.source_info.span), "unsupported statement")?,
}
}

View file

@ -6,6 +6,7 @@ struct Foo<const N: u8>([u8; N as usize])
where
[(); N as usize]:;
struct Bar<const N: u8>([u8; (N + 2) as usize]) where [(); (N + 2) as usize]:;
// unifying with subtrees
struct Evaluatable<const N: u16>;
@ -13,6 +14,5 @@ fn foo<const N: u8>() where Evaluatable<{N as usize as u16 }>: {
let _ = Foo::<N>([1; N as usize]);
}
struct Bar<const N: u8>([u8; (N + 2) as usize]) where [(); (N + 2) as usize]:;
fn main() {}

View file

@ -14,7 +14,7 @@ struct Foo2<const N: u8>(Evaluatable::<{N as u128}>) where Evaluatable<{N as usi
//~| help: try adding a `where` bound using this expression: `where [(); {N as u128}]:`
struct Bar<const N: u8>([u8; (N + 2) as usize]) where [(); (N + 1) as usize]:;
//~^ unconstrained generic constant
//~^ Error: unconstrained generic constant
//~| help: try adding a `where` bound using this expression: `where [(); (N + 2) as usize]:`
fn main() {}

View file

@ -0,0 +1,47 @@
#![feature(const_generics, const_evaluatable_checked)]
#![allow(incomplete_features)]
trait Trait {}
pub struct EvaluatableU128<const N: u128>;
struct HasCastInTraitImpl<const N: usize, const M: u128>;
impl<const O: usize> Trait for HasCastInTraitImpl<O, { O as u128 }> {}
pub fn use_trait_impl<const N: usize>()
where
[(); { N + 1}]:,
EvaluatableU128<{N as u128}>:, {
fn assert_impl<T: Trait>() {}
// errors are bad but seems to be pre-existing issue #86198
assert_impl::<HasCastInTraitImpl<{ N + 1 }, { N as u128 }>>();
//~^ Error: mismatched types
//~^^ Error: unconstrained generic constant
assert_impl::<HasCastInTraitImpl<{ N + 1 }, { N as _ }>>();
//~^ Error: mismatched types
//~^^ Error: unconstrained generic constant
assert_impl::<HasCastInTraitImpl<13, { 12 as u128 }>>();
//~^ Error: mismatched types
assert_impl::<HasCastInTraitImpl<14, 13>>();
//~^ Error: mismatched types
}
pub fn use_trait_impl_2<const N: usize>()
where
[(); { N + 1}]:,
EvaluatableU128<{N as _}>:, {
fn assert_impl<T: Trait>() {}
// errors are bad but seems to be pre-existing issue #86198
assert_impl::<HasCastInTraitImpl<{ N + 1 }, { N as u128 }>>();
//~^ Error: mismatched types
//~^^ Error: unconstrained generic constant
assert_impl::<HasCastInTraitImpl<{ N + 1 }, { N as _ }>>();
//~^ Error: mismatched types
//~^^ Error: unconstrained generic constant
assert_impl::<HasCastInTraitImpl<13, { 12 as u128 }>>();
//~^ Error: mismatched types
assert_impl::<HasCastInTraitImpl<14, 13>>();
//~^ Error: mismatched types
}
fn main() {}

View file

@ -0,0 +1,139 @@
error: unconstrained generic constant
--> $DIR/abstract-const-as-cast-3.rs:17:5
|
LL | fn assert_impl<T: Trait>() {}
| ----- required by this bound in `use_trait_impl::assert_impl`
...
LL | assert_impl::<HasCastInTraitImpl<{ N + 1 }, { N as u128 }>>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: try adding a `where` bound using this expression: `where [(); { O as u128 }]:`
note: required because of the requirements on the impl of `Trait` for `HasCastInTraitImpl<{ N + 1 }, { N as u128 }>`
--> $DIR/abstract-const-as-cast-3.rs:8:22
|
LL | impl<const O: usize> Trait for HasCastInTraitImpl<O, { O as u128 }> {}
| ^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error[E0308]: mismatched types
--> $DIR/abstract-const-as-cast-3.rs:17:5
|
LL | assert_impl::<HasCastInTraitImpl<{ N + 1 }, { N as u128 }>>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `{ N as u128 }`, found `{ O as u128 }`
|
= note: expected type `{ N as u128 }`
found type `{ O as u128 }`
error: unconstrained generic constant
--> $DIR/abstract-const-as-cast-3.rs:20:5
|
LL | fn assert_impl<T: Trait>() {}
| ----- required by this bound in `use_trait_impl::assert_impl`
...
LL | assert_impl::<HasCastInTraitImpl<{ N + 1 }, { N as _ }>>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: try adding a `where` bound using this expression: `where [(); { O as u128 }]:`
note: required because of the requirements on the impl of `Trait` for `HasCastInTraitImpl<{ N + 1 }, { N as _ }>`
--> $DIR/abstract-const-as-cast-3.rs:8:22
|
LL | impl<const O: usize> Trait for HasCastInTraitImpl<O, { O as u128 }> {}
| ^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error[E0308]: mismatched types
--> $DIR/abstract-const-as-cast-3.rs:20:5
|
LL | assert_impl::<HasCastInTraitImpl<{ N + 1 }, { N as _ }>>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `{ N as _ }`, found `{ O as u128 }`
|
= note: expected type `{ N as _ }`
found type `{ O as u128 }`
error[E0308]: mismatched types
--> $DIR/abstract-const-as-cast-3.rs:23:5
|
LL | assert_impl::<HasCastInTraitImpl<13, { 12 as u128 }>>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `12_u128`, found `13_u128`
|
= note: expected type `12_u128`
found type `13_u128`
error[E0308]: mismatched types
--> $DIR/abstract-const-as-cast-3.rs:25:5
|
LL | assert_impl::<HasCastInTraitImpl<14, 13>>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `13_u128`, found `14_u128`
|
= note: expected type `13_u128`
found type `14_u128`
error: unconstrained generic constant
--> $DIR/abstract-const-as-cast-3.rs:35:5
|
LL | fn assert_impl<T: Trait>() {}
| ----- required by this bound in `use_trait_impl_2::assert_impl`
...
LL | assert_impl::<HasCastInTraitImpl<{ N + 1 }, { N as u128 }>>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: try adding a `where` bound using this expression: `where [(); { O as u128 }]:`
note: required because of the requirements on the impl of `Trait` for `HasCastInTraitImpl<{ N + 1 }, { N as u128 }>`
--> $DIR/abstract-const-as-cast-3.rs:8:22
|
LL | impl<const O: usize> Trait for HasCastInTraitImpl<O, { O as u128 }> {}
| ^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error[E0308]: mismatched types
--> $DIR/abstract-const-as-cast-3.rs:35:5
|
LL | assert_impl::<HasCastInTraitImpl<{ N + 1 }, { N as u128 }>>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `{ N as u128 }`, found `{ O as u128 }`
|
= note: expected type `{ N as u128 }`
found type `{ O as u128 }`
error: unconstrained generic constant
--> $DIR/abstract-const-as-cast-3.rs:38:5
|
LL | fn assert_impl<T: Trait>() {}
| ----- required by this bound in `use_trait_impl_2::assert_impl`
...
LL | assert_impl::<HasCastInTraitImpl<{ N + 1 }, { N as _ }>>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: try adding a `where` bound using this expression: `where [(); { O as u128 }]:`
note: required because of the requirements on the impl of `Trait` for `HasCastInTraitImpl<{ N + 1 }, { N as _ }>`
--> $DIR/abstract-const-as-cast-3.rs:8:22
|
LL | impl<const O: usize> Trait for HasCastInTraitImpl<O, { O as u128 }> {}
| ^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error[E0308]: mismatched types
--> $DIR/abstract-const-as-cast-3.rs:38:5
|
LL | assert_impl::<HasCastInTraitImpl<{ N + 1 }, { N as _ }>>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `{ N as _ }`, found `{ O as u128 }`
|
= note: expected type `{ N as _ }`
found type `{ O as u128 }`
error[E0308]: mismatched types
--> $DIR/abstract-const-as-cast-3.rs:41:5
|
LL | assert_impl::<HasCastInTraitImpl<13, { 12 as u128 }>>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `12_u128`, found `13_u128`
|
= note: expected type `12_u128`
found type `13_u128`
error[E0308]: mismatched types
--> $DIR/abstract-const-as-cast-3.rs:43:5
|
LL | assert_impl::<HasCastInTraitImpl<14, 13>>();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `13_u128`, found `14_u128`
|
= note: expected type `13_u128`
found type `14_u128`
error: aborting due to 12 previous errors
For more information about this error, try `rustc --explain E0308`.

View file

@ -0,0 +1,29 @@
// check-pass
#![feature(const_evaluatable_checked, const_generics)]
#![allow(incomplete_features)]
trait Trait {}
pub struct EvaluatableU128<const N: u128>;
struct HasCastInTraitImpl<const N: usize, const M: u128>;
impl<const O: usize> Trait for HasCastInTraitImpl<O, { O as u128 }> {}
pub fn use_trait_impl<const N: usize>() where EvaluatableU128<{N as u128}>:, {
fn assert_impl<T: Trait>() {}
assert_impl::<HasCastInTraitImpl<N, { N as u128 }>>();
assert_impl::<HasCastInTraitImpl<N, { N as _ }>>();
assert_impl::<HasCastInTraitImpl<12, { 12 as u128 }>>();
assert_impl::<HasCastInTraitImpl<13, 13>>();
}
pub fn use_trait_impl_2<const N: usize>() where EvaluatableU128<{N as _}>:, {
fn assert_impl<T: Trait>() {}
assert_impl::<HasCastInTraitImpl<N, { N as u128 }>>();
assert_impl::<HasCastInTraitImpl<N, { N as _ }>>();
assert_impl::<HasCastInTraitImpl<12, { 12 as u128 }>>();
assert_impl::<HasCastInTraitImpl<13, 13>>();
}
fn main() {}