Remove `cfg(bootstrap)` code for array implementations
In https://github.com/rust-lang/rust/pull/62435 ("Use const generics for array impls [part 1]") the old macro-based implementations were not removed but still used with `cfg(bootstrap)` since the bootstrap compiler had some problems with const generics at the time. This does not seem to be the case anymore, so there is no reason to keep the old code.
Unfortunately, the diff is pretty ugly because much of the code was indented by one level before. The change is pretty trivial, though.
PS: I did not run the full test suite locally. There are 40°C outside and 31°C inside my room. I don't want my notebook to melt. I hope that CI is green.
r? @scottmcm
In PR #62435 ("Use const generics for array impls [part 1]") the old
macro-based implementations were not removed but still used with
`cfg(bootstrap)` since the bootstrap compiler had some problems with
const generics at the time. This does not seem to be the case anymore,
so there is no reason to keep the old code.
- uses a never-stable core::array::LengthAtMost32 to bound the impls
- includes a custom error message to avoid mentioning LengthAtMost32 too often
- doesn't use macros for the slice implementations to avoid #62433
Remove the default type of `Rem::Output`
Associated type defaults are not yet stable, and `Rem` is the only trait that specifies a default. Let's see what breaks when it's removed.
cc https://github.com/rust-lang/rust/pull/61812#issuecomment-502394566
cc @Centril
@bors try
Refactor core::iter module
A while back, I refactored `core::ops` in #42523 because the module had become a giant mess and was difficult to modify. Now, I'm doing the same with the `core::iter` module.
Like the `core::ops` refactor, things have been split up into multiple commits to make rebasing easier, and so that you can follow changes. Although the diffs are hard to decipher, the only actual code changes I've made in the first few commits are to modify exports and imports. I save all of the actual code refactoring, e.g. modifying what methods are called, for the end.
Add core::iter::once_with()
Functions `iter::once()` and `iter::repeat()` construct iterators from values. The latter has the lazy variant `iter::repeat_with()`, but the former doesn't. This PR therefore adds `iter::once_with()`.
Another way to think of `iter::once_with()` is that it's a function that converts `FnOnce() -> T` into `Iterator<Item = T>`.
If this seems like a reasonable addition, I'll open a tracking issue and update the `#[feature(...)]` attributes.
