Adds `impl<T, U> TryFrom<T> for U where U: From<T>`.
Removes `impl<'a, T> TryFrom<&'a str> for T where T: FromStr` due to
overlapping impls caused by the new blanket impl. This removal is to
be discussed further on the tracking issue for TryFrom.
Refs #33417.
Fix inconsistent doc headings
This fixes headings reading "Unsafety" and "Example", they should be "Safety" and "Examples" according to RFC 1574.
r? @steveklabnik
Generate builtin impls for `Clone`
This fixes a long-standing ICE and limitation where some builtin types implement `Copy` but not `Clone` (whereas `Clone` is a super trait of `Copy`).
However, this PR has a few side-effects:
* `Clone` is now marked as a lang item.
* `[T; N]` is now `Clone` if `T: Clone` (currently, only if `T: Copy` and for `N <= 32`).
* `fn foo<'a>() where &'a mut (): Clone { }` won't compile anymore because of how bounds for builtin traits are handled (e.g. same thing currently if you replace `Clone` by `Copy` in this example). Of course this function is unusable anyway, an error would pop as soon as it is called.
Hence, I'm wondering wether this PR would need an RFC...
Also, cc-ing @nikomatsakis, @arielb1.
Related issues: #28229, #24000.
Document that `std:#️⃣:Hasher::finish()` does not reset the hasher.
Clarifies the fact that `finish()` doesn’t in fact end or reset the hasher. This was surprising to me …
Follows up on and fixes#43763
Fix for issue #39827
*Cause of the issue*
While preparing for `trans_intrinsic_call()` invoke arguments are processed with `trans_argument()` method which excludes zero-sized types from argument list (to be more correct - all arguments for which `ArgKind` is `Ignore` are filtered out). As result `volatile_store()` intrinsic gets one argument instead of expected address and value.
*How it is fixed*
Modification of the `trans_argument()` method may cause side effects, therefore change was implemented in `volatile_store()` intrinsic building code itself. Now it checks function signature and if it was specialised with zero-sized type, then emits `C_nil()` instead of accessing non-existing second argument.
Improve std::ops docs
Fixes#29365. (This fixes all but one point from @steveklabnik's list, but that point was referring to examples of implementing range traits, but there are no range traits in std::ops.)
The main changes are quite a bit of copyediting, adding more "real" examples for some of the traits, incorporating some guidance from the API docs, more linking (cross-docs and to the book & reference), cleaning up examples, moving things around, and so on. Refer to the commit messages for more details.
Note: I decided to link to the second edition of the book since I think it's more appropriate now for the sections I linked, if this is not okay, please say so!
* fixed link typos and copy-paster errors
* rewrote Fn* explanations
* `RHS = Self` -> `RHS` is `Self` (added that to all applicable places as
well)
* fixed up some links
* s/MutDeref/DerefMut
* removed remaining superfluous `fn main()`s
* fixed some minor phrasings and factual errors and inaccuracies
std::ops docs: Fix phrasing and factual errors/inaccuracies
- updates documentation on volatile memory intrinsics, now the case of
zero-sized types is mentioned explicitly.
Volatile memory operations which doesn't affect memory at all are omitted
in LLVM backend, e.g. if number of elements is zero or type used in
generic specialisation is zero-sized, then LLVM intrinsic or related code
is not generated. This was not explicitly documented before in Rust
documentation and potentially could cause issues.
