Tracking issue for ambiguous_associated_items compatibility lint
#57644
Labels
A-lint
Area: Lints (warnings about flaws in source code) such as unused_mut.
C-future-compatibility
Category: Future-compatibility lints
T-compiler
Relevant to the compiler team, which will review and decide on the PR/issue.
T-lang
Relevant to the language team, which will review and decide on the PR/issue.
Comments
petrochenkov
added
A-lint
This was referenced Apr 30, 2019
kennytm
added a commit
to kennytm/rust
that referenced
this issue
May 2, 2019
Make deprecation lint `ambiguous_associated_items` deny-by-default As requested by r? @Centril cc rust-lang#57644
Centril
added a commit
to Centril/rust
that referenced
this issue
May 2, 2019
Make deprecation lint `ambiguous_associated_items` deny-by-default As requested by r? @Centril cc rust-lang#57644
Centril
added a commit
to Centril/rust
that referenced
this issue
May 3, 2019
Make deprecation lint `ambiguous_associated_items` deny-by-default As requested by r? @Centril cc rust-lang#57644
illicitonion
pushed a commit
to illicitonion/num_enum
that referenced
this issue
Jun 30, 2019
Hello,
my enum looks like that:
```rust
#[derive(IntoPrimitive, TryFromPrimitive, Copy, Clone, PartialEq, Debug)]
#[repr(u8)]
pub enum BasicTokenNoPrefix {
EndOfTokenisedLine = 0,
StatementSeparator = 1,
[...]
Error,
[...]
}
```
and I obtain this compilation error when using it:
```
error: ambiguous associated item
--> src/basic/tokens.rs:7:10
|
7 | #[derive(IntoPrimitive, TryFromPrimitive, Copy, Clone, PartialEq, Debug)]
| ^^^^^^^^^^^^^^^^
|
= note: #[deny(ambiguous_associated_items)] on by default
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #57644 <rust-lang/rust#57644>
note: `Error` could refer to variant defined here
--> src/basic/tokens.rs:145:5
|
14| Error,
| ^^^^^
note: `Error` could also refer to associated type defined here
```
This patch allows to fix this issue.
How is a variant present in type namespace? Syntactically only type is possible in that position, a function can't return a variant of an enum. |
tylerwhall
added a commit
to tylerwhall/strum
that referenced
this issue
Nov 18, 2021
The addition of TryFrom<&str> for EnumString breaks for enums that have
a variant called "Error". Rewrite as <Self as Trait> where associated
types are used as the return type for trait functions.
Example:
```rust
pub enum Test {
Error,
}
```
error: ambiguous associated item
--> src/lib.rs:3:10
|
3 | #[derive(EnumString)]
| ^^^^^^^^^^
|
= note: `#[deny(ambiguous_associated_items)]` on by default
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #57644 <rust-lang/rust#57644>
tylerwhall
added a commit
to tylerwhall/strum
that referenced
this issue
Nov 18, 2021
The addition of TryFrom<&str> for EnumString breaks for enums that have
a variant called "Error". Rewrite as <Self as Trait> where associated
types are used as the return type for trait functions.
Example:
```rust
pub enum Test {
Error,
}
```
error: ambiguous associated item
--> src/lib.rs:3:10
|
3 | #[derive(EnumString)]
| ^^^^^^^^^^
|
= note: `#[deny(ambiguous_associated_items)]` on by default
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #57644 <rust-lang/rust#57644>
tylerwhall
added a commit
to tylerwhall/strum
that referenced
this issue
Nov 18, 2021
The addition of TryFrom<&str> for EnumString breaks for enums that have
a variant called "Error". Rewrite as <Self as Trait> where associated
types are used as the return type for trait functions.
Example:
```rust
#[derive(EnumString)]
pub enum Test {
Error,
}
```
error: ambiguous associated item
--> src/lib.rs:3:10
|
3 | #[derive(EnumString)]
| ^^^^^^^^^^
|
= note: `#[deny(ambiguous_associated_items)]` on by default
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #57644 <rust-lang/rust#57644>
tylerwhall
added a commit
to tylerwhall/strum
that referenced
this issue
Nov 18, 2021
The addition of TryFrom<&str> for EnumString breaks for enums that have
a variant called "Error". Rewrite as <Self as Trait> where associated
types are used as the return type for trait functions.
Example:
```rust
#[derive(EnumString)]
pub enum Test {
Error,
}
```
error: ambiguous associated item
--> src/lib.rs:3:10
|
3 | #[derive(EnumString)]
| ^^^^^^^^^^
|
= note: `#[deny(ambiguous_associated_items)]` on by default
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #57644 <rust-lang/rust#57644>
tylerwhall
added a commit
to tylerwhall/strum
that referenced
this issue
Nov 19, 2021
The addition of TryFrom<&str> for EnumString breaks for enums that have
a variant called "Error". Rewrite as <Self as Trait> where associated
types are used as the return type for trait functions.
Example:
```rust
pub enum Test {
Error,
}
```
error: ambiguous associated item
--> src/lib.rs:3:10
|
3 | #[derive(EnumString)]
| ^^^^^^^^^^
|
= note: `#[deny(ambiguous_associated_items)]` on by default
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #57644 <rust-lang/rust#57644>
Peternator7
pushed a commit
to Peternator7/strum
that referenced
this issue
Nov 19, 2021
The addition of TryFrom<&str> for EnumString breaks for enums that have
a variant called "Error". Rewrite as <Self as Trait> where associated
types are used as the return type for trait functions.
Example:
```rust
pub enum Test {
Error,
}
```
error: ambiguous associated item
--> src/lib.rs:3:10
|
3 | #[derive(EnumString)]
| ^^^^^^^^^^
|
= note: `#[deny(ambiguous_associated_items)]` on by default
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #57644 <rust-lang/rust#57644>
hunts
pushed a commit
to hunts/capnproto-rust
that referenced
this issue
Jan 30, 2023
This was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! See also: rust-lang/rust#57644
hunts
added a commit
to hunts/capnproto-rust
that referenced
this issue
Jan 30, 2023
This was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! See also: rust-lang/rust#57644
hunts
added a commit
to hunts/capnproto-rust
that referenced
this issue
Jan 30, 2023
This was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! See also: rust-lang/rust#57644
hunts
added a commit
to hunts/capnproto-rust
that referenced
this issue
Jan 30, 2023
This was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! See also: rust-lang/rust#57644
caspermeijn
added a commit
to caspermeijn/prost
that referenced
this issue
Jul 9, 2024
The generated code uses `Self::Error` to refer to `::prost::UnknownEnumValue`, but the term `Error` is not unique when an enum variant is called `Error`. Use the full type name to resolve the ambiguity.
The compiler reported:
```
error: ambiguous associated item
--> /home/ircdev/src/prost/target/debug/build/tests-no-std-e27db7197924752f/out/enum_keyword_variant.rs:2:68
|
2 | #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord, ::prost::Enumeration)]
| ^^^^^^^^^^^^^^^^^^^^
|
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #57644 <rust-lang/rust#57644>
note: `Error` could refer to the variant defined here
--> /home/ircdev/src/prost/target/debug/build/tests-no-std-e27db7197924752f/out/enum_keyword_variant.rs:10:5
|
10 | Error = 4,
| ^^^^^
note: `Error` could also refer to the associated type defined here
--> /home/ircdev/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/convert/mod.rs:682:5
|
682 | type Error;
| ^^^^^^^^^^
= note: `#[deny(ambiguous_associated_items)]` on by default
= note: this error originates in the derive macro `::prost::Enumeration` (in Nightly builds, run with -Z macro-backtrace for more info)
```
github-merge-queue bot
pushed a commit
to tokio-rs/prost
that referenced
this issue
Jul 9, 2024
The generated code uses `Self::Error` to refer to `::prost::UnknownEnumValue`, but the term `Error` is not unique when an enum variant is called `Error`. Use the full type name to resolve the ambiguity.
The compiler reported:
```
error: ambiguous associated item
--> /home/ircdev/src/prost/target/debug/build/tests-no-std-e27db7197924752f/out/enum_keyword_variant.rs:2:68
|
2 | #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord, ::prost::Enumeration)]
| ^^^^^^^^^^^^^^^^^^^^
|
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #57644 <rust-lang/rust#57644>
note: `Error` could refer to the variant defined here
--> /home/ircdev/src/prost/target/debug/build/tests-no-std-e27db7197924752f/out/enum_keyword_variant.rs:10:5
|
10 | Error = 4,
| ^^^^^
note: `Error` could also refer to the associated type defined here
--> /home/ircdev/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/convert/mod.rs:682:5
|
682 | type Error;
| ^^^^^^^^^^
= note: `#[deny(ambiguous_associated_items)]` on by default
= note: this error originates in the derive macro `::prost::Enumeration` (in Nightly builds, run with -Z macro-backtrace for more info)
```
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
What is this lint about
With variants being resolved as inherent associated items (rust-lang/rfcs#2338) code like this become ambiguous:
This is not a problem right now, because variants cannot be used in type positions, but it may become a problem in the future if rust-lang/rfcs#2593 is accepted.
So this lints warns against cases like this and recommends to rewrite them as
<Self as Tr>::V.How to fix this warning/error
Explicitly disambiguate in favor of associated types from traits:
<Type as Trait>::Ambiguous.Current status
ambiguous_associated_itemslint as warn-by-defaultambiguous_associated_itemsdeny-by-default #59928 makes theambiguous_associated_itemslint deny-by-defaultambiguous_associated_itemslint a hard errorThe text was updated successfully, but these errors were encountered: