Implement RFC 2056 trivial constraints in where clauses
This is an implementation of the new behaviour for #48214. Tests are mostly updated to show the effects of this. Feature gate hasn't been added yet.
Some things that are worth noting and are maybe not want we want
* `&mut T: Copy` doesn't allow as much as someone might expect because there is often an implicit reborrow.
* ~There isn't a check that a where clause is well-formed any more, so `where Vec<str>: Debug` is now allowed (without a `str: Sized` bound).~
r? @nikomatsakis
In Copy derive, report all fulfillment erros when present and do not
report errors for types tainted with `TyErr`. Also report all fields
which are not Copy rather than just the first.
Also refactored `fn fully_normalize`, removing the not very useful
helper function along with a FIXME to the closed issue #26721 that's
looks out of context now.
Optimize layout of TypeVariants
This makes references to `Slice` use thin pointers by storing the slice length in the slice itself. `GeneratorInterior` is replaced by storing the movability of generators in `TyGenerator` and the interior witness is stored in `GeneratorSubsts` (which is just a wrapper around `&'tcx Substs`, like `ClosureSubsts`). Finally the fields of `TypeAndMut` is stored inline in `TyRef`. These changes combine to reduce `TypeVariants` from 48 bytes to 24 bytes on x86_64.
r? @michaelwoerister
Refactor auto trait handling in librustdoc to be accessible from librustc.
These commits transfer some of the functionality introduced in https://github.com/rust-lang/rust/pull/47833 to librustc with the intention of making the tools to work with auto traits accessible to third-party code, for example [rust-semverver](https://github.com/rust-lang-nursery/rust-semverver).
Some rough edges remain, and I'm certain some of the FIXMEs introduced will need some discussion, most notably the fairly ugly overall approach to pull out the core logic into librustc, which was previously fairly tightly coupled with various bits and bobs from librustdoc.
cc @Aaron1011
We store the obligation that caused the overflow as part of the OverflowError, and report it at the public API endpoints (rather than in the implementation internals).
Remove universes from `ty::ParamEnv`
This change was never meant to land. #48407 takes an alternate approach. However, that PR is now blocked on some issues with canonicalization, and rebasing these reverts gets harder each time, so let's just get this bit out of the way now.
r? @nikomatsakis
- `ParamEnv::empty()` -- does not reveal all, good for typeck
- `ParamEnv::reveal_all()` -- does, good for trans
- `param_env.with_reveal_all()` -- converts an existing parameter environment
Fix exponential projection complexity on nested types
This implements solution 1 from https://github.com/rust-lang/rust/issues/38528#issuecomment-366263076.
The code quality is currently extremely poor, but we can improve them during review.
Blocking issues:
- we probably don't want a quadratic deduplication for obligations.
- is there an alternative to deduplication?
Based on #48315.
Needs changelog. Noticable improvement on compile time is expected.
Fix#38528Close#39684Close#43757
detect wrong number of args when type-checking a closure
Instead of creating inference variables for those argument types, use
the trait error-reporting code to give a nicer error. This also
improves some other spans for existing tests.
Fixes#47244
r? @estebank
Irina Popa
bors
varkor
Matthew Jasper
leonardo.yvens
John Kåre Alsaker
Aravind Gollakota
Inokentiy Babushkin
Tyler Mandry
Niko Matsakis
Fabian Zaiser
Tatsuyuki Ishi
Alex Crichton
scalexm
Sean Griffin
csmoe
Andrew Cann
Oliver Schneider
kennytm
Mark Mansi
Manish Goregaokar