Libs highlights
Full report
The following RFCs are entering their final comment period:
The following features are entering their final comment period:
Here are the decisions for last week’s FCP items:
-
FCP PR #1105:
RFC: Policy on semver and API evolution
-
FCP PR #1119:
Quick draft “Result::expect” rfc
-
FCP PR #1123:
RFC: introduce
split_at(mid: usize) on str
-
FCP PR #1034:
RFC: Deprecate
Iterator::size_hint and ExactSizeIterator for better named alternatives.
The following feature is going to the core team for final stabilization approval:
Lang highlights
Full report
The following RFCs are entering final comment period:
-
PR #1156:
Adjust default object bounds. (breaking change)
- Since time is of the essence here, this RFC is being
promoted to FCP immediately.
- This is a breaking change that is being suggested because the
current defaults have some shortcomings that seem worth
correcting, and all evidence indicates that making this change
will have negligible impact (details are in the RFC) in existing
code. This would be an exception from normal policy.
- Some prior discussion took place in a
thread on internals.
-
PR #873:
Allow macros in types
-
PR #865:
Amendment to associated items RFC to account for the const/static split.
-
PR #756:
Allow closure expressions to expand to a & or &mut temporary
The following RFCs have been around a long time without much
action. It is not clear whether we are ready to reach a final
decision, but I’d like to encourage comments. These RFCs are likely to
enter FCP next week.
-
PR #197:
ManuallyDrop trait, which allows types to disable the
"automatic drop" their inline content that currently occurs.
-
PR #638:
Specifies behavior during unwinding, particularly with respect
to non-Rust code.
-
PR #890:
RFC: Custom preludes.
Last week we moved a number of RFCs into the final comment
period. Here is the outcome:
-
PR #1131:
Add an expect intrinsic.
-
PR #1052:
Clarify cast rules, especially regarding fat pointers.
- Still hammering out final details.
-
PR #1122:
Semantic versioning for the language.
-
PR #987:
Modify RFC #803 (type ascription) to make type ascription expressions lvalues
Tools highlights
Full report
This was a fairly quiet week for tooling, but progress continues to be made on
various fronts. MSVC continues to be blocked on upgrading LLVM, which has
run into another segfault and may take some time to investigate
and fix. @nrc made some great progress on tracking performance metrics for the
compiler, and the frontend is looking quite nice! @brson also continues to
rewrite crater in Rust, soon enabling you to test a change against all of
crates.io from home.
Soon nightlies for MSVC will also be available (note that unwinding still does
not work), and shortly thereafter Cargo MSVC-host nightlies will also likely be
available. This support also lends itself nicely to generating MUSL nightlies
as well!
Compiler highlights
Full report
The major event this week is that @arielb1 has been added as a
contributor to the compiler subteam. @arielb1 has been making numerous
changes to the compiler, and in particular has landed a number of
patches lately making improvements to compilation time. Thanks
@arielb1!