bors 6672c16afc Auto merge of #121204 - cuviper:flatten-one-shot, r=the8472 ... Specialize flattening iterators with only one inner item For iterators like `Once` and `option::IntoIter` that only ever have a single item at most, the front and back iterator states in `FlatMap` and `Flatten` are a waste, as they're always consumed already. We can use specialization for these types to simplify the iterator methods. It's a somewhat common pattern to use `flatten()` for options and results, even recommended by [multiple][1] [clippy][2] [lints][3]. The implementation is more efficient with `filter_map`, as mentioned in [clippy#9377], but this new specialization should close some of that gap for existing code that flattens. [1]: https://rust-lang.github.io/rust-clippy/master/#filter_map_identity [2]: https://rust-lang.github.io/rust-clippy/master/#option_filter_map [3]: https://rust-lang.github.io/rust-clippy/master/#result_filter_map [clippy#9377]: https://github.com/rust-lang/rust-clippy/issues/9377		2024-02-17 20:18:54 +00:00
..
alloc	Rollup merge of #121149 - SebastianJL:patch-1, r=Mark-Simulacrum	2024-02-17 18:47:41 +01:00
backtrace@6145fe6bac	Update backtrace submodule	2023-11-21 16:33:42 +01:00
core	Auto merge of #121204 - cuviper:flatten-one-shot, r=the8472	2024-02-17 20:18:54 +00:00
panic_abort	rustc: implement support for riscv32im_risc0_zkvm_elf	2024-01-22 10:07:36 -08:00
panic_unwind	Step all bootstrap cfgs forward	2024-02-08 07:44:34 -05:00
portable-simd	Disable conversions between portable_simd and stdarch on big-endian ARM	2024-01-30 04:47:01 +00:00
proc_macro	Auto merge of #116385 - kornelski:maybe-rename, r=Amanieu	2024-02-16 14:11:10 +00:00
profiler_builtins	Add support for custom JSON targets when using build-std.	2024-02-05 10:20:42 +00:00
rtstartup	library: Fix warnings in rtstartup	2024-01-06 01:32:03 +03:00
rustc-std-workspace-alloc	Replace libstd, libcore, liballoc in line comments.	2022-12-30 14:00:42 +01:00
rustc-std-workspace-core
rustc-std-workspace-std
std	Rollup merge of #119032 - smmalis37:patch-1, r=ChrisDenton	2024-02-17 11:23:03 +01:00
stdarch@5ef6eb42bd	Update stdarch submodule	2024-01-30 03:33:12 +00:00
sysroot	Expose compiler-builtins-weak-intrinsics feature for -Zbuild-std	2023-06-23 11:15:34 +01:00
test	Actually abort in panic-abort-tests	2024-01-30 18:19:49 -08:00
unwind	Enable Static Builds for FreeBSD	2024-01-11 15:26:16 +00:00