Added doc about behavior of extend on HashMap
It was unclear what the implementation does when it encounters existing keys. This change makes it clear by documenting the trait impl.
Research suggests that we are not properly testing this case anyway, and
even if we were, it is unlikely that we will regress here -- or, perhaps
more accurately, if we do, I am uncertain that we care too much. It
definitely seems like an edge case, and one that is particularly
unlikely to occur as time goes on.
Currently rustdoc does not forward `-Z` options to rustc when building
test executables. This makes impossible to use rustdoc to run test
samples when crate under test is instrumented with one of sanitizers
`-Zsanitizer=...`, since the final linking step will not include
sanitizer runtime library.
Forward `-Z` options to rustc to solve the issue.
Helps with #43031.
File handles shouldn't be inheritable in general.
`std::process::Command` takes care of making them inheritable when child
processes are spawned, and the `CREATE_PROCESS_LOCK` protects against
races in that section on Windows. But `File::try_clone` has been
creating inheritable file descriptors outside of that lock, which could
be leaking into other child processes unintentionally.
See also https://github.com/rust-lang/rust/pull/31069#discussion_r334117665.
The dummy Span pointed to the beginning of the source file instead to
where the `#[derive]` is located. Later, it tripped the
`in_derive_expansion(span)` check at `src/librustc/middle/stability.rs`,
causing a span-less deprecation warning to be emitted.
Fixes#56195, #55417.
Union fields may now never have a type with attached destructor.
This for example allows unions to use arbitrary field types only by
wrapping
them in ManuallyDrop.
The stable rule remains, that union fields must be Copy. We use the new
rule for the `untagged_union` feature.
See RFC 2514.
Note for ui tests:
We can't test move out through Box's deref-move since we can't
have a Box in a union anymore.
minimize the rust-std component
This changes the `rust-std` dist component to only include the artifacts of compiling the `libstd` step, as listed in `.libstd.stamp`. This does include `test` and `proc-macro` as well. The remaining _unstable_ libraries that are built as part of `rustc` are packaged into a new `rustc-dev` component, intended for use in the development of closely related tools (clippy, miri, rls).
Here are the component sizes from the [try build](https://dev-static.rust-lang.org/dist/2019-10-07/index.html):
| Name | Size
| --- | ---
| rust-std-nightly-x86_64-unknown-linux-gnu.tar.gz | 23.94 MiB
| rust-std-nightly-x86_64-unknown-linux-gnu.tar.xz | 17.4 MiB
| rustc-dev-nightly-x86_64-unknown-linux-gnu.tar.gz | 182.03 MiB
| rustc-dev-nightly-x86_64-unknown-linux-gnu.tar.xz | 157.91 MiB
Fixes#61978Fixes#62486
