This commit improves the Clone trait documentation to address confusion
around what "duplication" means for different types, especially for smart
pointers like Arc<Mutex<T>>.
Signed-off-by: xizheyin <xizheyin@smail.nju.edu.cn>
* Clarify relationship to `dyn` after #133003.
* Add an example of using it with `dyn` as #133003 enabled.
* Add an example of implementing it.
* Add links to Rust Reference for the mentioned concepts.
* Mention that its method should rarely be called.
* Replace parameter name `dst` with `dest` to avoids confusion between
“DeSTination” and “Dynamically-Sized Type”.
* Various small corrections.
Use `std::mem::{size_of, size_of_val, align_of, align_of_val}` from the
prelude instead of importing or qualifying them.
These functions were added to all preludes in Rust 1.80.
This trait allows cloning DSTs, but is unsafe to implement and use
because it writes to possibly-uninitialized memory which must be of the
correct size, and must initialize that memory.
It is only implemented for `T: Clone` and `[T] where T: Clone`, but
additional implementations could be provided for specific `dyn Trait`
or custom-DST types.
This reverts commit 049a917535.
The resolution to <https://github.com/rust-lang/rust/issues/123282> is
that the `f16`/`f128` regression in the beta compiler was fixable
without a revert, so the commit adding `#[cfg(not(bootstrap))]` is no
longer useful (added in
<https://github.com/rust-lang/rust/pull/123390>).
Revert this commit because not having these basic impls bootstrap-gated
simplifies everything else that uses them.
detects redundant imports that can be eliminated.
for #117772 :
In order to facilitate review and modification, split the checking code and
removing redundant imports code into two PR.
