fn add_const_impl(
acc: &mut Completions,
ctx: &CompletionContext<'_>,
replacement_range: TextRange,
const_: Const,
impl_def: Impl,
)fn add_const_impl(
acc: &mut Completions,
ctx: &CompletionContext<'_>,
replacement_range: TextRange,
const_: Const,
impl_def: Impl,
)