rust/library/core/tests/lib.rs
bors b33e234155 Auto merge of #79895 - Kerollmops:slice-group-by, r=m-ou-se
The return of the GroupBy and GroupByMut iterators on slice

According to https://github.com/rust-lang/rfcs/pull/2477#issuecomment-742034372, I am opening this PR again, this time I implemented it in safe Rust only, it is therefore much easier to read and is completely safe.

This PR proposes to add two new methods to the slice, the `group_by` and `group_by_mut`. These two methods provide a way to iterate over non-overlapping sub-slices of a base slice that are separated by the predicate given by the user (e.g. `Partial::eq`, `|a, b| a.abs() < b.abs()`).

```rust
let slice = &[1, 1, 1, 3, 3, 2, 2, 2];

let mut iter = slice.group_by(|a, b| a == b);
assert_eq!(iter.next(), Some(&[1, 1, 1][..]));
assert_eq!(iter.next(), Some(&[3, 3][..]));
assert_eq!(iter.next(), Some(&[2, 2, 2][..]));
assert_eq!(iter.next(), None);
```

[An RFC](https://github.com/rust-lang/rfcs/pull/2477) was open 2 years ago but wasn't necessary.
2020-12-31 12:00:43 +00:00

117 lines
2.6 KiB
Rust

#![feature(alloc_layout_extra)]
#![feature(array_chunks)]
#![feature(array_from_ref)]
#![feature(array_methods)]
#![feature(array_map)]
#![feature(array_windows)]
#![feature(bool_to_option)]
#![feature(bound_cloned)]
#![feature(box_syntax)]
#![feature(cell_update)]
#![feature(cfg_panic)]
#![feature(cfg_target_has_atomic)]
#![feature(const_assume)]
#![feature(const_cell_into_inner)]
#![feature(const_maybe_uninit_assume_init)]
#![feature(const_ptr_read)]
#![feature(const_ptr_offset)]
#![feature(core_intrinsics)]
#![feature(core_private_bignum)]
#![feature(core_private_diy_float)]
#![feature(debug_non_exhaustive)]
#![feature(dec2flt)]
#![feature(div_duration)]
#![feature(duration_consts_2)]
#![feature(duration_constants)]
#![feature(duration_saturating_ops)]
#![feature(duration_zero)]
#![feature(exact_size_is_empty)]
#![feature(fixed_size_array)]
#![feature(flt2dec)]
#![feature(fmt_internals)]
#![feature(hashmap_internals)]
#![feature(try_find)]
#![feature(is_sorted)]
#![feature(pattern)]
#![feature(raw)]
#![feature(sort_internals)]
#![feature(slice_partition_at_index)]
#![feature(maybe_uninit_extra)]
#![feature(maybe_uninit_write_slice)]
#![feature(min_specialization)]
#![feature(step_trait)]
#![feature(step_trait_ext)]
#![feature(str_internals)]
#![feature(test)]
#![feature(trusted_len)]
#![feature(try_trait)]
#![feature(slice_internals)]
#![feature(slice_partition_dedup)]
#![feature(int_error_matching)]
#![feature(array_value_iter)]
#![feature(iter_advance_by)]
#![feature(iter_partition_in_place)]
#![feature(iter_intersperse)]
#![feature(iter_is_partitioned)]
#![feature(iter_order_by)]
#![feature(cmp_min_max_by)]
#![feature(iter_map_while)]
#![feature(const_mut_refs)]
#![feature(const_pin)]
#![feature(const_slice_from_raw_parts)]
#![feature(const_raw_ptr_deref)]
#![feature(never_type)]
#![feature(unwrap_infallible)]
#![feature(option_unwrap_none)]
#![feature(peekable_next_if)]
#![feature(peekable_peek_mut)]
#![feature(partition_point)]
#![feature(once_cell)]
#![feature(unsafe_block_in_unsafe_fn)]
#![feature(int_bits_const)]
#![feature(nonzero_leading_trailing_zeros)]
#![feature(const_option)]
#![feature(integer_atomics)]
#![feature(slice_group_by)]
#![deny(unsafe_op_in_unsafe_fn)]
extern crate test;
mod alloc;
mod any;
mod array;
mod ascii;
mod atomic;
mod bool;
mod cell;
mod char;
mod clone;
mod cmp;
#[cfg(not(bootstrap))]
mod const_ptr;
mod fmt;
mod hash;
mod intrinsics;
mod iter;
mod lazy;
mod macros;
mod manually_drop;
mod mem;
mod nonzero;
mod num;
mod ops;
mod option;
mod pattern;
mod pin;
mod ptr;
mod result;
mod slice;
mod str;
mod str_lossy;
mod task;
mod time;
mod tuple;
mod unicode;