Don't have Vec<T> delegate to [T]'s bounds for indexing

This commit is contained in:
Jonathan Behrens
2018-03-02 23:23:00 -05:00
parent ae73a21081
commit 370df40dab
2 changed files with 12 additions and 8 deletions

View File

@@ -1527,23 +1527,27 @@ impl<T: Hash> Hash for Vec<T> {
#[stable(feature = "rust1", since = "1.0.0")] #[stable(feature = "rust1", since = "1.0.0")]
#[rustc_on_unimplemented = "vector indices are of type `usize` or ranges of `usize`"] #[rustc_on_unimplemented = "vector indices are of type `usize` or ranges of `usize`"]
impl<T, I> Index<I> for Vec<T> where [T]: Index<I> { impl<T, I> Index<I> for Vec<T>
type Output = <[T] as Index<I>>::Output; where
I: ::core::slice::SliceIndex<[T]>,
{
type Output = I::Output;
#[inline] #[inline]
fn index(&self, index: I) -> &Self::Output { fn index(&self, index: I) -> &Self::Output {
// NB indexing via implementation on slice Index::index(&**self, index)
&(**self)[index]
} }
} }
#[stable(feature = "rust1", since = "1.0.0")] #[stable(feature = "rust1", since = "1.0.0")]
#[rustc_on_unimplemented = "vector indices are of type `usize` or ranges of `usize`"] #[rustc_on_unimplemented = "vector indices are of type `usize` or ranges of `usize`"]
impl<T, I> IndexMut<I> for Vec<T> where [T]: IndexMut<I> { impl<T, I> IndexMut<I> for Vec<T>
where
I: ::core::slice::SliceIndex<[T]>,
{
#[inline] #[inline]
fn index_mut(&mut self, index: I) -> &mut Self::Output { fn index_mut(&mut self, index: I) -> &mut Self::Output {
// NB indexing via implementation on slice IndexMut::index_mut(&mut **self, index)
&mut (**self)[index]
} }
} }

View File

@@ -5,7 +5,7 @@ LL | x[0i32]; //~ ERROR E0277
| ^^^^^^^ slice indices are of type `usize` or ranges of `usize` | ^^^^^^^ slice indices are of type `usize` or ranges of `usize`
| |
= help: the trait `std::slice::SliceIndex<[{integer}]>` is not implemented for `i32` = help: the trait `std::slice::SliceIndex<[{integer}]>` is not implemented for `i32`
= note: required because of the requirements on the impl of `std::ops::Index<i32>` for `[{integer}]` = note: required because of the requirements on the impl of `std::ops::Index<i32>` for `std::vec::Vec<{integer}>`
error: aborting due to previous error error: aborting due to previous error