Compiler
Full report
Perhaps the most exciting thing going on right now is @huon’s PR
implementing the groundwork for SIMD. We’ve also decided
to merge the MIR RFC.
Lang
Full report
The following RFCs were promoted to final comment period:
-
RFC #1229, which
specifies that when the compiler is doing constant evaluation as a
form of optimization, it should not report compilation errors for
overflows or other problems that are encountered (warnings are ok).
Otherwise, improvements in the constant evaluator can become
breaking changes.
-
RFC #1234, which
modifies the DST coercion rules to permit
PhantomData. The
discussion has primarily focused on whether we can indeed make the
rules even more accepting than that; conclusion was to leave this
for future work.
Full list of T-lang RFCs in FCP.
Some fine fellow (ahem) also started a scintillating discussion on
the interaction of type parameter fallback with integral fallback
started on internals, which would benefit from more eyeballs:
Last week, we had a number of RFCs enter FCP. Unfortunately, we did
not reach final decisions on very many of them, due to Felix Klock
being out for some well-earned R&R. However, we did merge a few
noncontroversial items:
-
RFC #1209 updates
the follow set for types in macros to include
;.
-
RFC #1189 fixes
some typos.
We also decided to close several RFCs for prioritization reasons, even
if the ideas espoused had merit:
Libs
Full report
Starting with the current release cycle (for 1.4), we are making some
changes to the stabilization process:
-
All unstable APIs
now map to tracking issues. The
APIs will be tagged with the issue tracking them, so when you get an
error that you need a feature gate, the compiler can also tell you
which issue to subscribe to for stabilization. We’ll use these
issues as a centralized place for discussing questions/concerns
about APIs before they are stabilized.
-
Stabilization will be tied to our 6 week release cycles: at the
beginning of the cycle, the team will announce a number of unstable
features undergoing “final comment period” (heading either toward
stabilization or deprecation). The comment period will last for the
entire release cycle. One week before the release is cut, the team
will make final decisions and land a PR accordingly.
This new process such give much more visibility into the feature
pipeline and make the stabilization process easier to follow.
With that in mind, here are the features undergoing FCP for this cycle:
In addition, this week we made the following decisions:
-
FCP PR #1195:
ordered query API
- Close, with the hope that we can find a way to achieve these goals
with a smaller API surface
-
FCP PR #1192:
RFC for inclusive ranges with …
- Merge, with the extra field for
Iterator being kept unstable for
the time being.
Finally, the following RFC is entering FCP this week:
-
FCP PR #1198:
pretty print
Debug of tuples, tuple structs and enum variants in a single line
Tools
Full report
These past two weeks saw a number of exciting events!
