Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Rollup of 6 pull requests #39833

Closed
wants to merge 13 commits into from
Closed
Changes from 2 commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
9 changes: 6 additions & 3 deletions src/librustc/traits/error_reporting.rs
Original file line number Diff line number Diff line change
@@ -36,7 +36,6 @@ use ty::fold::TypeFolder;
use ty::subst::Subst;
use util::nodemap::{FxHashMap, FxHashSet};

use std::cmp;
use std::fmt;
use syntax::ast;
use hir::{intravisit, Local, Pat};
@@ -392,12 +391,16 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
return;
}

let end = cmp::min(4, impl_candidates.len());
let end = if impl_candidates.len() <= 5 {
impl_candidates.len()
} else {
4
};
err.help(&format!("the following implementations were found:{}{}",
&impl_candidates[0..end].iter().map(|candidate| {
format!("\n {:?}", candidate)
}).collect::<String>(),
if impl_candidates.len() > 4 {
if impl_candidates.len() > 5 {
format!("\nand {} others", impl_candidates.len() - 4)
} else {
"".to_owned()
37 changes: 37 additions & 0 deletions src/test/ui/did_you_mean/issue-39802-show-5-trait-impls.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,37 @@
// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

trait Foo<B> {
fn bar(&self){}
}

impl Foo<u8> for i8 {}
impl Foo<u16> for i8 {}
impl Foo<u32> for i8 {}
impl Foo<u64> for i8 {}
impl Foo<bool> for i8 {}

impl Foo<u16> for u8 {}
impl Foo<u32> for u8 {}
impl Foo<u64> for u8 {}
impl Foo<bool> for u8 {}

impl Foo<u8> for bool {}
impl Foo<u16> for bool {}
impl Foo<u32> for bool {}
impl Foo<u64> for bool {}
impl Foo<bool> for bool {}
impl Foo<i8> for bool {}

fn main() {
Foo::<i32>::bar(&1i8);
Foo::<i32>::bar(&1u8);
Foo::<i32>::bar(&true);
}
43 changes: 43 additions & 0 deletions src/test/ui/did_you_mean/issue-39802-show-5-trait-impls.stderr
Original file line number Diff line number Diff line change
@@ -0,0 +1,43 @@
error[E0277]: the trait bound `i8: Foo<i32>` is not satisfied
--> $DIR/issue-39802-show-5-trait-impls.rs:34:5
|
34 | Foo::<i32>::bar(&1i8);
| ^^^^^^^^^^^^^^^ the trait `Foo<i32>` is not implemented for `i8`
|
= help: the following implementations were found:
<i8 as Foo<u8>>
<i8 as Foo<u16>>
<i8 as Foo<u32>>
<i8 as Foo<u64>>
<i8 as Foo<bool>>
= note: required by `Foo::bar`

error[E0277]: the trait bound `u8: Foo<i32>` is not satisfied
--> $DIR/issue-39802-show-5-trait-impls.rs:35:5
|
35 | Foo::<i32>::bar(&1u8);
| ^^^^^^^^^^^^^^^ the trait `Foo<i32>` is not implemented for `u8`
|
= help: the following implementations were found:
<u8 as Foo<u16>>
<u8 as Foo<u32>>
<u8 as Foo<u64>>
<u8 as Foo<bool>>
= note: required by `Foo::bar`

error[E0277]: the trait bound `bool: Foo<i32>` is not satisfied
--> $DIR/issue-39802-show-5-trait-impls.rs:36:5
|
36 | Foo::<i32>::bar(&true);
| ^^^^^^^^^^^^^^^ the trait `Foo<i32>` is not implemented for `bool`
|
= help: the following implementations were found:
<bool as Foo<u8>>
<bool as Foo<u16>>
<bool as Foo<u32>>
<bool as Foo<u64>>
and 2 others
= note: required by `Foo::bar`

error: aborting due to 3 previous errors