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Diffstat (limited to 'crates/hir-ty/src/generics.rs')
| -rw-r--r-- | crates/hir-ty/src/generics.rs | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/crates/hir-ty/src/generics.rs b/crates/hir-ty/src/generics.rs index a96c101a38..89ca707c2e 100644 --- a/crates/hir-ty/src/generics.rs +++ b/crates/hir-ty/src/generics.rs @@ -225,6 +225,23 @@ impl Generics { } } +pub(crate) fn trait_self_param_idx(db: &dyn DefDatabase, def: GenericDefId) -> Option<usize> { + match def { + GenericDefId::TraitId(_) | GenericDefId::TraitAliasId(_) => { + let params = db.generic_params(def); + params.trait_self_param().map(|idx| idx.into_raw().into_u32() as usize) + } + GenericDefId::ImplId(_) => None, + _ => { + let parent_def = parent_generic_def(db, def)?; + let parent_params = db.generic_params(parent_def); + let parent_self_idx = parent_params.trait_self_param()?.into_raw().into_u32() as usize; + let self_params = db.generic_params(def); + Some(self_params.len() + parent_self_idx) + } + } +} + fn parent_generic_def(db: &dyn DefDatabase, def: GenericDefId) -> Option<GenericDefId> { let container = match def { GenericDefId::FunctionId(it) => it.lookup(db).container, |