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Clean up E0741 error explanation

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Guillaume Gomez 2020-07-31 13:15:47 +02:00
parent 9e92106d45
commit 1a6730e31c
1 changed files with 8 additions and 4 deletions
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12
src/librustc_error_codes/error_codes/E0741.md
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@ -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!