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| author | Esteban Küber <esteban@kuber.com.ar> | 2022-12-26 17:44:16 -0800 |
|---|---|---|
| committer | Esteban Küber <esteban@kuber.com.ar> | 2022-12-26 18:21:45 -0800 |
| commit | 1b341fe8a1ce3c4922b5e39aee6c4375e05b6750 (patch) | |
| tree | 6d1c5394974f67e1f4bdb314b3a492917678c506 /src | |
| parent | caa64e5b5e7605a1c1428b2a402021bef83f3e1e (diff) | |
| download | rust-1b341fe8a1ce3c4922b5e39aee6c4375e05b6750.tar.gz rust-1b341fe8a1ce3c4922b5e39aee6c4375e05b6750.zip | |
Suggest `impl Iterator` when possible for `_` return type
Address #106096.
Diffstat (limited to 'src')
| -rw-r--r-- | src/test/ui/typeck/typeck_type_placeholder_item.rs | 8 | ||||
| -rw-r--r-- | src/test/ui/typeck/typeck_type_placeholder_item.stderr | 23 |
2 files changed, 30 insertions, 1 deletions
diff --git a/src/test/ui/typeck/typeck_type_placeholder_item.rs b/src/test/ui/typeck/typeck_type_placeholder_item.rs index 22fedb22d66..b96c5271339 100644 --- a/src/test/ui/typeck/typeck_type_placeholder_item.rs +++ b/src/test/ui/typeck/typeck_type_placeholder_item.rs @@ -220,3 +220,11 @@ fn value() -> Option<&'static _> { const _: Option<_> = map(value); //~^ ERROR the placeholder `_` is not allowed within types on item signatures for constants + +fn evens_squared(n: usize) -> _ { +//~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types + (1..n).filter(|x| x % 2 == 0).map(|x| x * x) +} + +const _: _ = (1..10).filter(|x| x % 2 == 0).map(|x| x * x); +//~^ ERROR the placeholder `_` is not allowed within types on item signatures for constants diff --git a/src/test/ui/typeck/typeck_type_placeholder_item.stderr b/src/test/ui/typeck/typeck_type_placeholder_item.stderr index c57f71b8057..034bdae5f2e 100644 --- a/src/test/ui/typeck/typeck_type_placeholder_item.stderr +++ b/src/test/ui/typeck/typeck_type_placeholder_item.stderr @@ -428,6 +428,27 @@ LL | const _: Option<_> = map(value); | not allowed in type signatures | help: replace with the correct type: `Option<u8>` +error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types + --> $DIR/typeck_type_placeholder_item.rs:224:31 + | +LL | fn evens_squared(n: usize) -> _ { + | ^ + | | + | not allowed in type signatures + | help: replace with an appropriate return type: `impl Iterator<Item = usize>` + +error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants + --> $DIR/typeck_type_placeholder_item.rs:229:10 + | +LL | const _: _ = (1..10).filter(|x| x % 2 == 0).map(|x| x * x); + | ^ not allowed in type signatures + | +note: however, the inferred type `Map<Filter<std::ops::Range<i32>, [closure@$DIR/typeck_type_placeholder_item.rs:229:29: 229:32]>, [closure@$DIR/typeck_type_placeholder_item.rs:229:49: 229:52]>` cannot be named + --> $DIR/typeck_type_placeholder_item.rs:229:14 + | +LL | const _: _ = (1..10).filter(|x| x % 2 == 0).map(|x| x * x); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions --> $DIR/typeck_type_placeholder_item.rs:140:31 | @@ -636,7 +657,7 @@ LL | const D: _ = 42; | not allowed in type signatures | help: replace with the correct type: `i32` -error: aborting due to 69 previous errors +error: aborting due to 71 previous errors Some errors have detailed explanations: E0121, E0282, E0403. For more information about an error, try `rustc --explain E0121`. |