forked from rust-lang/rust
-
Notifications
You must be signed in to change notification settings - Fork 1
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Rollup merge of rust-lang#23025 - huonw:better-iter-infer, r=Gankro
This concretely improves type inference of some cases (see included test). I assume the compiler struggles to reason about multiple layers of generic type parameters (even with associated-type equalities) but *can* understand pure associated types, since they are always directly computable from the input types. Thanks to @shepmaster for noticing the issue with `Cloned` (I took that example as a test case).
- Loading branch information
Showing
2 changed files
with
73 additions
and
46 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,25 @@ | ||
// 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. | ||
|
||
// Test to see that the element type of .cloned() can be inferred | ||
// properly. Previously this would fail to deduce the type of `sum`. | ||
|
||
#![feature(core)] | ||
|
||
use std::iter::AdditiveIterator; | ||
|
||
fn square_sum(v: &[i64]) -> i64 { | ||
let sum = v.iter().cloned().sum(); | ||
sum * sum | ||
} | ||
|
||
fn main() { | ||
assert_eq!(36, square_sum(&[1,2,3])); | ||
} |