OpenE2K/rust
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Rollup merge of #74977 - GuillaumeGomez:cleanup-e0741, r=pickfire

Browse Source 
Clean up E0741 error explanation

r? @Dylan-DPC
This commit is contained in:
Manish Goregaokar 2020-08-01 09:30:11 -07:00 committed by GitHub
commit 60bf83d215
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 8 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
src/librustc_error_codes/error_codes/E0741.md
View File

@ -1,5 +1,6 @@
Only structural-match types (that is, types that derive `PartialEq` and `Eq`)
may be used as the types of const generic parameters.
A non-structural-match type was used as the type of a const generic parameter.
Erroneous code example:
```compile_fail,E0741
#![feature(const_generics)]
@ -9,12 +10,15 @@ struct A;
struct B<const X: A>; // error!
```
To fix this example, we derive `PartialEq` and `Eq`.
Only structural-match types (that is, types that derive `PartialEq` and `Eq`)
may be used as the types of const generic parameters.
To fix the previous code example, we derive `PartialEq` and `Eq`:
```
#![feature(const_generics)]
#[derive(PartialEq, Eq)]
#[derive(PartialEq, Eq)] // We derive both traits here.
struct A;
struct B<const X: A>; // ok!