diff options
Diffstat (limited to 'src/libcore/slice')
| -rw-r--r-- | src/libcore/slice/mod.rs | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/src/libcore/slice/mod.rs b/src/libcore/slice/mod.rs index df4d97ee6a4..9f9515e6d9b 100644 --- a/src/libcore/slice/mod.rs +++ b/src/libcore/slice/mod.rs @@ -2383,7 +2383,6 @@ impl [u8] { } #[stable(feature = "rust1", since = "1.0.0")] -#[rustc_on_unimplemented = "slice indices are of type `usize` or ranges of `usize`"] impl<T, I> ops::Index<I> for [T] where I: SliceIndex<[T]> { @@ -2396,7 +2395,6 @@ impl<T, I> ops::Index<I> for [T] } #[stable(feature = "rust1", since = "1.0.0")] -#[rustc_on_unimplemented = "slice indices are of type `usize` or ranges of `usize`"] impl<T, I> ops::IndexMut<I> for [T] where I: SliceIndex<[T]> { @@ -2447,7 +2445,19 @@ mod private_slice_index { /// A helper trait used for indexing operations. #[stable(feature = "slice_get_slice", since = "1.28.0")] -#[rustc_on_unimplemented = "slice indices are of type `usize` or ranges of `usize`"] +#[rustc_on_unimplemented( + on( + T = "str", + label = "string indices are ranges of `usize`", + ), + on( + all(any(T = "str", T = "&str", T = "std::string::String"), _Self="{integer}"), + note="you can use `.chars().nth()` or `.bytes().nth()` +see chapter in The Book <https://doc.rust-lang.org/book/ch08-02-strings.html#indexing-into-strings>" + ), + message = "the type `{T}` cannot be indexed by `{Self}`", + label = "slice indices are of type `usize` or ranges of `usize`", +)] pub trait SliceIndex<T: ?Sized>: private_slice_index::Sealed { /// The output type returned by methods. #[stable(feature = "slice_get_slice", since = "1.28.0")] |