Commit graph

2 commits

Author SHA1 Message Date
Keith-Cancel
73a991fb9d Allow provisional mgca syntax of type const <IDENT> = <EXPR> to be reconized.
Revert, but without type const.

Update symbol for feature err, then update suggestion output, and lastly update tests that change because of those.

Update these new tests with the correct syntax, and few existing tests with the new outputs the merge with main added.

Fix for tidyfmt and some errors when manually resolving a merge conflicts.

Update these tests to use update error messages and type const syntax.

Update comments and error message to use new syntax instead of old type_const attribute.

Remove the type_const attribute

update some more tests to use the new syntax.

Update these test cases.

update feature gate test

Change gate logic for `mgca_type_const_syntax` to work also if `min_generic_const_args` is enabled.

Create a new feature gate that checks for the feature before expansion.

Make rustfmt handle the `type const` syntax correctly.

Add a convience method to check if a RhsKind is type const.

Rename `Const` discriminant to `Body` for `ConstItemRhsKind`

Give the `TraitItemKind` flag an enum instead of a simple bool to better describe what the flag is for.

Update formatting for these match statements.

Update clippy test to use type const syntax.

Update test to use type const syntax.

update rustfmt to match ast items.

Update clippy to match ast and hir items.

Few more test cases that used old attribute, instead of 'type const'

Update to match the output from the feature gate checks.

tidyfmt adjustments.

Update the is_type_const, so I can constrain record!(..) in encoder.rs

Update conditional compilation test.

Move the feature gate to after expansion to allow for cfg(...) to work.

Update some more tests to use the new syntax.

Update type const tests in associated-const-bindings to use new syntax.

Don't check based off the attribute, but the item here.

Update some tests outside of the const_generics folder that were using #[type_const]

update the tests in associated consts that use #[type_const] to use type const

Update these mgca tests with the type const syntax.

Add a flag to TraitItemKind for detecting type const for now. Maybe later change ItemConstRhs to have optional consts but that touches a lot more lines of code.

Don't need into for these now that it's a query.

Add is_type_const query to handle foreign def ids.

update this test to use type const syntax.

Fix logic here, we only want to lower if there is expression in this case.

Update built-in macros to use ConstItemRhsKind

Update more instance of the old ConstItemRhs.

Rename ConstItemKind to ConstItemRhsKind, I noticed there is a typed called ConstantItemKind, so add the Rhs to the name to avoid confusion.

Update lower to use ConstItemKind

Add an other helper method to check if the rhs kinda has an expr.

Update item parse to use ConstItemKind enum.

Felt the field name could a be little clear when editing a few other things.

Change the ConstItem struct see know if we have a type const or regular const.

Make sure this syntax is properly feature gated.
2026-02-09 07:59:24 -08:00
Noah Lev
9a30ec8149 Implement MVP for opaque generic const arguments
This is meant to be the interim successor to generic const expressions.
Essentially, const item RHS's will be allowed to do arbitrary const
operations using generics. The limitation is that these const items will
be treated opaquely, like ADTs in nominal typing, such that uses of them
will only be equal if the same const item is referenced. In other words,
two const items with the exact same RHS will not be considered equal.

I also added some logic to check feature gates that depend on others
being enabled (like oGCA depending on mGCA).

= Coherence =

During coherence, OGCA consts should be normalized ambiguously because
they are opaque but eventually resolved to a real value. We don't want
two OGCAs that have the same value to be treated as distinct for
coherence purposes. (Just like opaque types.)

This actually doesn't work yet because there are pre-existing
fundamental issues with equate relations involving consts that need to
be normalized. The problem is that we normalize only one layer of the
const item and don't actually process the resulting anon const. Normally
the created inference variable should be handled, which in this case
would cause us to hit the anon const, but that's not happening.
Specifically, `visit_const` on `Generalizer` should be updated to be
similar to `visit_ty`.
2026-02-08 18:15:11 +00:00