closes#21630
Overloaded indexing (`&[mut] foo[bar]`) only works when `<Self as Index>::Output` is the same as `<Self as IndexMut>::Output` (see issue above). To restrict implementations of `IndexMut` that doesn't work, this PR makes `IndexMut` a supertrait over `Index`, i.e. `trait IndexMut<I>: Index<I>`, just like in the `trait DerefMut: Deref` case.
This breaks all downstream implementations of `IndexMut`, in most cases this simply means removing the `type Output = ..` bit, which is now redundant, from `IndexMut` implementations:
``` diff
impl Index<Foo> for Bar {
type Output = Baz;
..
}
impl IndexMut<Foo> for Bar {
- type Output = Baz;
..
}
```
[breaking-change]
---
r? @nikomatsakis
New functions, `slice::from_raw_parts` and `slice::from_raw_parts_mut`,
are added to implement the lifetime convention as agreed in rust-lang/rfcs#556.
The functions `slice::from_raw_buf` and `slice::from_raw_mut_buf` are
left deprecated for the time being.
Holding back on changing the signature of `std::ffi::c_str_to_bytes` as consensus in rust-lang/rfcs#592 is building to replace it with a composition of other functions.
Contribution to #21923.
If you were still using `MaybeOwnedVector`, update your code to use `CowVec`.
[breaking-change]
---
We already removed `MaybeOwned` (the string equivalent) long time ago and with a much shorter deprecation period. It's time to let go.
The word is repeated twice in the message like:
error: obsolete syntax: `:`, `&mut:`, or `&:` syntax
This removes the word syntax that appears in messages after the second colon (:).
Second try to address https://github.com/rust-lang/rust/issues/21196 . A lot that was removed at the end basically seemed repetitive showing simple variations on the same type. It seems more effective to just show more variants at the beginning instead.
If you want to pack values into an example, better to use `i32` or some digit than `String` because you don't need the `to_string()` method.
I didn't mention `derive` because:
* I can't explain it (only use it)
* I don't have a link to a good description (maybe rustbyexample but you probably want links internal)
* Giving more detail especially stating that `==` won't work and why should help quite a bit
I didn't `make test` or check links but I will if this will be merged.
@steveklabnik
The word is repeated twice in the message like
error: obsolete syntax: `:`, `&mut:`, or `&:` syntax
This removes the word syntax that appears in messages after the second colon (:).
....
The 'stable_features' lint helps people progress from unstable to
stable Rust by telling them when they no longer need a `feature`
attribute because upstream Rust has declared it stable.
This compares to the existing 'unstable_features' lint, which is used
to implement feature staging, and triggers on *any* use
of `#[feature]`.
New functions, `slice::from_raw_parts` and `slice::from_raw_parts_mut`,
are added to implement the lifetime convention as agreed in rust-lang/rfcs#556.
The functions `slice::from_raw_buf` and `slice::from_raw_mut_buf` are
left deprecated for the time being.
Holding back on changing the signature of `std::ffi::c_str_to_bytes` as consensus in rust-lang/rfcs#592 is building to replace it with a composition of other functions.
Contribution to #21923.
This is 99% burning ints to the ground, but I also got rid of useless annotations or made code more \"idiomatic\" as I went along. Mostly changes in tests.
This was particularly helpful in the time just after OIBIT's
implementation to make sure things that were supposed to be Copy
continued to be, but it's now creates a lot of noise for types that
intentionally don't want to be Copy.
r? @alexcrichton
Currently \"k / 2\" generates one (k: uint) or two (k: int) \"br false,
...\" instructions and the corresponding basic blocks, producing quite
some noise and making the code unnecessarily hard to read.
Additionally we can skip translation if the code would end up
unreachable anyway.
This also removes two erroneous re-exports of the Entry variants, and so is incidentally a [breaking-change], though presumably no one should have been using those.
r? @aturon
- add `_SC_GETPW_R_SIZE_MAX` constant
- declare `struct passwd`
- convert `load_self` to `current_exe`
Note: OpenBSD don't provide system function to return a valuable Path
for `env::current_exe`. The implementation is currently based on the
value of `argv[0]`, which couldn't be used when executable is called via
PATH.
This can be considered partial work on #8256.
The main observable change: macro expansion sometimes results in spans where `lo > hi`; so for now, when we have such a span, do not attempt to return a snippet result.
(Longer term, we might think about whether we could still present a snippet for the cases where this arises, e.g. perhaps by showing the whole macro as the snippet, assuming that is the sole cause of such spans; or by somehow looking up the closest AST node that holds both `lo` and `hi`, and showing that.)
As a drive-by, revised the API to return a `Result` rather than an `Option`, with better information-packed error value that should help us (and maybe also our users) identify the causes of such problems in the future. Ideally the call-sites that really want an actual snippet would be updated to catch the newly added `Err` case and print something meaningful about it, but that is not part of this PR.
improve `compiletest` error message when path option missing.
I often run `compiletest` by hand by cut-and-pasting from what `make` runs, (which I observe via `remake --trace`), but then I need to tweak it (cut out options) and its useful to be told when I have removed an option that is actually required, such as `--android-cross-path=path`.)
Ported regions-mock-tcx to use TypedArena rather than Arena since it holds cyclic structure (which the Arena API updated for the Drop-Check-Rule cannot handle).
Plus, the use of `arena::Arena` here really is not justified; the allocated values are all the same type anyway.
