In 1.49.0, the definition of Box was modified to support an optional
Allocator[1]. Adapt the parsing of the `box` keyword to supply the
expected number of parameters to the constructor.
[1] f288cd2e17
7133: Proper handling $crate and local_inner_macros r=jonas-schievink a=edwin0cheng
This PR introduces `HygineFrames` to store the macro definition/call site hierarchy in hyginee and when resolving `local_inner_macros` and `$crate`, we use the token to look up the corresponding frame and return the correct value.
See also: https://rustc-dev-guide.rust-lang.org/macro-expansion.html#hygiene-and-hierarchies
fixe #6890 and #6788
r? @jonas-schievink
Co-authored-by: Edwin Cheng <edwin0cheng@gmail.com>
Without arbitrary self types, the self type could never refer to the method type
parameters, so this wasn't a problem; but with arbitrary self types, it can.
This fixes the crash from #6668; but it doesn't make method resolution work for
these methods.
5971: Implement async blocks r=flodiebold a=oxalica
Fix#4018
@flodiebold already gave a generic guide in the issue. Here's some concern about implementation detail:
- Chalk doesn't support generator type yet.
- Adding generator type as a brand new type (ctor) can be complex and need to *re-introduced* builtin impls. (Like how we implement closures before native closure support of chalk, which is already removed in #5401 )
- The output type of async block should be known after type inference of the whole body.
- We cannot directly get the type from source like return-positon-impl-trait. But we still need to provide trait bounds when chalk asking for `opaque_ty_data`.
- During the inference, the output type of async block can be temporary unknown and participate the later inference.
`let a = async { None }; let _: i32 = a.await.unwrap();`
So in this PR, the type of async blocks is inferred as an opaque type parameterized by the `Future::Output` type it should be, like what we do with closure type.
And it really works now.
Well, I still have some questions:
- The bounds `AsyncBlockImplType<T>: Future<Output = T>` is currently generated in `opaque_ty_data`. I'm not sure if we should put this code here.
- Type of async block is now rendered as `impl Future<Output = OutputType>`. Do we need to special display to hint that it's a async block? Note that closure type has its special format, instead of `impl Fn(..) -> ..` or function type.
Co-authored-by: oxalica <oxalicc@pm.me>
