This trait has proven quite useful when defining marker traits to avoid the
semi-confusing `PhantomFn` trait and it looks like it will continue to be a
useful tool for defining these traits.
I often have to run `ast-json` or look into the pretty-printer source to figure out what the fields of an AST enum mean. I've tried to document most of what I know (and some semi-obvious stuff).
r? @steveklabnik
f? @eddyb
The alignment field is actually a \"pointer sized\" type instead of always i64,
requiring that the size of the padding field is also calculated slightly
differently.
Closes#23425
Very minor fix: in `std::net::Ipv6Addr::new`, the documentation had an incomplete representation of the resulting address, missing the last two groups.
This commit clarifies some of the unstable features in the `str` module by
moving them out of the blanket `core` and `collections` features.
The following methods were moved to the `str_char` feature which generally
encompasses decoding specific characters from a `str` and dealing with the
result. It is unclear if any of these methods need to be stabilized for 1.0 and
the most conservative route for now is to continue providing them but to leave
them as unstable under a more specific name.
* `is_char_boundary`
* `char_at`
* `char_range_at`
* `char_at_reverse`
* `char_range_at_reverse`
* `slice_shift_char`
The following methods were moved into the generic `unicode` feature as they are
specifically enabled by the `unicode` crate itself.
* `nfd_chars`
* `nfkd_chars`
* `nfc_chars`
* `graphemes`
* `grapheme_indices`
* `width`
This patch changes the type of byte string literals from `&[u8]` to `&[u8; N]`.
It also implements some necessary traits (`IntoBytes`, `Seek`, `Read`, `BufRead`) for fixed-size arrays (also related to #21725) and adds test for #17233, which seems to be resolved.
Fixes#18465
[breaking-change]
Safe fns are no longer subtypes of unsafe fns, but you can coerce from one to the other.
This is a [breaking-change] in that impl fns must now be declared `unsafe` if the trait is declared `unsafe`. In some rare cases, the subtyping change may also direct affect you, but no such cases were encountered in practice.
Fixes#23449.
r? @nrc
This commit stabilizes the `cloned` iterator after tweaking the signature to
require that the iterator is over `&T` instead of `U: Deref<T>`. This method has
had time to bake for awhile now and it's not clear whether the `Deref` bound is
worth it. Additionally, there aren't clear conventions on when to bound and/or
implement the `Deref` trait, so for now the conservative route is to require
references instead of `U: Deref<T>`.
To change this signature to using `Deref` would technically be a
backwards-incompatible change, but it is doubtful that any code will actually
break in practice.
This commit clarifies some of the unstable features in the `str` module by
moving them out of the blanket `core` and `collections` features.
The following methods were moved to the `str_char` feature which generally
encompasses decoding specific characters from a `str` and dealing with the
result. It is unclear if any of these methods need to be stabilized for 1.0 and
the most conservative route for now is to continue providing them but to leave
them as unstable under a more specific name.
* `is_char_boundary`
* `char_at`
* `char_range_at`
* `char_at_reverse`
* `char_range_at_reverse`
* `slice_shift_char`
The following methods were moved into the generic `unicode` feature as they are
specifically enabled by the `unicode` crate itself.
* `nfd_chars`
* `nfkd_chars`
* `nfc_chars`
* `graphemes`
* `grapheme_indices`
* `width`
Final remnant of reflection is gone. Also, virtual `Trait` destructors are no longer tied to `Box`.
That means they can be used to drop any instance of the type (used in libarena to replace TyDesc).
This is [breaking-change] for direct users of intrinsics:
* use `intrinsics::type_name::<T>()` instead of `(*intrinsics::get_tydesc::<T>()).name`
* the only way to get the destructor is from a trait object's vtable (see libarena changes)
r? @pcwalton f? @dotdash
The alignment field is actually a "pointer sized" type instead of always i64,
requiring that the size of the padding field is also calculated slightly
differently.
Closes#23425
This function is the current replacement for `std::old_io::timer` which will
soon be deprecated. This function is unstable and has its own feature gate as it
does not yet have an RFC nor has it existed for very long.
These two borrowing examples were confusing/misleading. This changes it
to more clearly show how you _can_ borrow a box, and also uses & instead
of &*.
This function is the current replacement for `std::old_io::timer` which will
soon be deprecated. This function is unstable and has its own feature gate as it
does not yet have an RFC nor has it existed for very long.
Very minor fix: in `std::net::Ipv6Addr::new`, the documentation had an incomplete representation of the resulting address, missing the last two groups.
This upcast coercion currently never requires vtable changes. It should be generalized.
This is a [breaking-change] -- if you have an impl on an object type like `impl SomeTrait`, then this will no longer be applicable to object types like `SomeTrait+Send`. In the standard library, this primarily affected `Any`, and this PR adds impls for `Any+Send` as to keep the API the same in practice. An alternate workaround is to use UFCS form or standalone fns. For more details, see <https://github.com/rust-lang/rust/issues/18737#issuecomment-78450798>.
r? @nrc
