3918: Add support for feature attributes in struct literal r=matklad a=bnjjj
As promised here is the next PR to solve 2 different scenarios with feature flag on struct literal.
close#3870
Co-authored-by: Benjamin Coenen <5719034+bnjjj@users.noreply.github.com>
We treat macro calls as expressions (there's appropriate Into impl),
which causes problem if there's expresison and non-expression macro in
the same node (like in the match arm).
We fix this problem by nesting macor patterns into another node (the
same way we nest path into PathExpr or PathPat). Ideally, we probably
should add a similar nesting for macro expressions, but that needs
some careful thinking about macros in blocks: `{ am_i_expression!() }`.
It improves compile time in `--release` mode quite a bit, it doesn't
really slow things down and, conceptually, it seems closer to what we
want the physical architecture to look like (we don't want to
monomorphise EVERYTHING in a single leaf crate).
E.g. in `match x { None => ... }`, `None` is a path pattern (resolving to the
option variant), not a binding. To determine this, we need to try to resolve the
name during lowering. This isn't too hard since we already need to resolve names
for macro expansion anyway (though maybe a bit hacky).
Fixes#1618.
3062: Implement slice pattern AST > HIR lowering r=jplatte a=jplatte
WIP. The necessary changes for parsing are implemented, but actual inference is not yet. Just wanted to upload what I've got so far so it doesn't get duplicated :)
Will fix#3043
Co-authored-by: Jonas Platte <jplatte+git@posteo.de>
